[
  {
    "path": ".github/FUNDING.yml",
    "content": "custom: https://paypal.me/angelocomp/10\n"
  },
  {
    "path": "README.md",
    "content": "# SimpleModbus NG\n\nSimpleModbus is a collection of Arduino libraries that enables you to communicate serially using the Modicon Modbus RTU protocol.\n\nThis project was born as an updated version of http://code.google.com/p/simple-modbus/ by Bester Juan because it lacks support for commands other than 3 and 16. More important the code is now on github, so you can contribute more easily.\n\nThis projects is actively maintained, so feel free to ask for features or reporting bugs!\n\n## Features\n\nThis library adds support for command 6 and provides a more extensive support for arduino pins. \nThe goal of the project is to support all usable MODBUS commands on arduino and expose all arduino pins so you can use an arduino as an advanced automation controller for both analog/digital in/out.\n\nNEW: Support for SoftwareSerial, really useful on AtTiny85. You can find both library and an example that works reliable on attiny85 microcontroller.\n\n## Usage\nSimply copy the SimpleModbusMaster or SimpleModbusSlave or both into your Arduino IDE **libraries** folder. Than restart the ide and open the corresponding example into the example_master or example_slave folder.\n"
  },
  {
    "path": "SimpleModbusMaster/SimpleModbusMaster.cpp",
    "content": "#include \"SimpleModbusMaster.h\"\r\n\r\n#define BUFFER_SIZE 128\r\n\r\n// modbus specific exceptions\r\n#define ILLEGAL_FUNCTION 1\r\n#define ILLEGAL_DATA_ADDRESS 2\r\n#define ILLEGAL_DATA_VALUE 3\r\n\r\nunsigned char transmission_ready_Flag;\r\nunsigned char messageOkFlag, messageErrFlag;\r\nunsigned char retry_count;\r\nunsigned char TxEnablePin;\r\n// frame[] is used to recieve and transmit packages.\r\n// The maximum number of bytes in a modbus packet is 256 bytes\r\n// This is limited to the serial buffer of 128 bytes\r\nunsigned char frame[BUFFER_SIZE];\r\nunsigned int timeout, polling;\r\nunsigned int T1_5; // inter character time out in microseconds\r\nunsigned int T3_5; // frame delay in microseconds\r\nunsigned long previousTimeout, previousPolling;\r\nunsigned int total_no_of_packets;\r\nPacket* packet; // current packet\r\n\r\n// function definitions\r\nvoid constructPacket();\r\nvoid checkResponse();\r\nvoid check_F3_data(unsigned char buffer);\r\nvoid check_F16_data();\r\nunsigned char getData();\r\nvoid check_packet_status();\r\nunsigned int calculateCRC(unsigned char bufferSize);\r\nvoid sendPacket(unsigned char bufferSize);\r\n\r\n\r\nunsigned int modbus_update(Packet* packets)\r\n{\r\n    // Initialize the connection_status variable to the\r\n    // total_no_of_packets. This value cannot be used as\r\n    // an index (and normally you won't). Returning this\r\n    // value to the main skecth informs the user that the\r\n    // previously scanned packet has no connection error.\r\n\r\n    unsigned int connection_status = total_no_of_packets;\r\n\r\n    if (transmission_ready_Flag) {\r\n\r\n        static unsigned int packet_index;\r\n\r\n        unsigned int failed_connections = 0;\r\n\r\n        unsigned char current_connection;\r\n\r\n        do {\r\n\r\n            if (packet_index == total_no_of_packets) // wrap around to the beginning\r\n                packet_index = 0;\r\n\r\n            // proceed to the next packet\r\n            packet = &packets[packet_index];\r\n\r\n            // get the current connection status\r\n            current_connection = packet->connection;\r\n\r\n            if (!current_connection) {\r\n                connection_status = packet_index;\r\n\r\n                // If all the connection attributes are false return\r\n                // immediately to the main sketch\r\n                if (++failed_connections == total_no_of_packets)\r\n                    return connection_status;\r\n            }\r\n\r\n            packet_index++;\r\n\r\n        } while (!current_connection); // while a packet has no connection get the next one\r\n\r\n        constructPacket();\r\n    }\r\n\r\n    checkResponse();\r\n\r\n    check_packet_status();\r\n\r\n    return connection_status;\r\n}\r\n\r\nvoid constructPacket()\r\n{\r\n    transmission_ready_Flag = 0; // disable the next transmission\r\n\r\n    packet->requests++;\r\n    frame[0] = packet->id;\r\n    frame[1] = packet->function;\r\n    frame[2] = packet->address >> 8; // address Hi\r\n    frame[3] = packet->address & 0xFF; // address Lo\r\n    frame[4] = packet->no_of_registers >> 8; // no_of_registers Hi\r\n    frame[5] = packet->no_of_registers & 0xFF; // no_of_registers Lo\r\n\r\n    unsigned int crc16;\r\n\r\n    // construct the frame according to the modbus function\r\n    if (packet->function == PRESET_MULTIPLE_REGISTERS) {\r\n        unsigned char no_of_bytes = packet->no_of_registers * 2;\r\n        unsigned char frameSize = 9 + no_of_bytes; // first 7 bytes of the array + 2 bytes CRC+ noOfBytes\r\n        frame[6] = no_of_bytes; // number of bytes\r\n        unsigned char index = 7; // user data starts at index 7\r\n        unsigned int temp;\r\n        unsigned char no_of_registers = packet->no_of_registers;\r\n        for (unsigned char i = 0; i < no_of_registers; i++) {\r\n            temp = packet->register_array[i]; // get the data\r\n            frame[index] = temp >> 8;\r\n            index++;\r\n            frame[index] = temp & 0xFF;\r\n            index++;\r\n        }\r\n        crc16 = calculateCRC(frameSize - 2);\r\n        frame[frameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n        frame[frameSize - 1] = crc16 & 0xFF;\r\n        sendPacket(frameSize);\r\n\r\n        if (packet->id == 0) { // check broadcast id\r\n            messageOkFlag = 1; // message successful, there will be no response on a broadcast\r\n            previousPolling = millis(); // start the polling delay\r\n        }\r\n    } else { // READ_HOLDING_REGISTERS is assumed\r\n        crc16 = calculateCRC(6); // the first 6 bytes of the frame is used in the CRC calculation\r\n        frame[6] = crc16 >> 8; // crc Lo\r\n        frame[7] = crc16 & 0xFF; // crc Hi\r\n        sendPacket(8); // a request with function 3, 4 & 6 is always 8 bytes in size\r\n    }\r\n}\r\n\r\nvoid checkResponse()\r\n{\r\n    if (!messageOkFlag && !messageErrFlag) { // check for response\r\n        unsigned char buffer = getData();\r\n\r\n        if (buffer > 0) { // if there's something in the buffer continue\r\n            if (frame[0] == packet->id) { // check id returned\r\n                // to indicate an exception response a slave will 'OR'\r\n                // the requested function with 0x80\r\n                if ((frame[1] & 0x80) == 0x80) { // exctract 0x80\r\n                    // the third byte in the exception response packet is the actual exception\r\n                    switch (frame[2]) {\r\n                    case ILLEGAL_FUNCTION:\r\n                        packet->illegal_function++;\r\n                        break;\r\n                    case ILLEGAL_DATA_ADDRESS:\r\n                        packet->illegal_data_address++;\r\n                        break;\r\n                    case ILLEGAL_DATA_VALUE:\r\n                        packet->illegal_data_value++;\r\n                        break;\r\n                    default:\r\n                        packet->misc_exceptions++;\r\n                    }\r\n                    messageErrFlag = 1; // set an error\r\n                    previousPolling = millis(); // start the polling delay\r\n                } else { // the response is valid\r\n                    if (frame[1] == packet->function) { // check function number returned\r\n                        // receive the frame according to the modbus function\r\n                        if (packet->function == PRESET_MULTIPLE_REGISTERS)\r\n                            check_F16_data();\r\n                        else // READ_HOLDING_REGISTERS is assumed\r\n                            check_F3_data(buffer);\r\n                    } else { // incorrect function number returned\r\n                        packet->incorrect_function_returned++;\r\n                        messageErrFlag = 1; // set an error\r\n                        previousPolling = millis(); // start the polling delay\r\n                    }\r\n                } // check exception response\r\n            } else { // incorrect id returned\r\n                packet->incorrect_id_returned++;\r\n                messageErrFlag = 1; // set an error\r\n                previousPolling = millis(); // start the polling delay\r\n            }\r\n        } // check buffer\r\n    } // check message booleans\r\n}\r\n\r\n// checks the time out and polling delay and if a message has been recieved succesfully\r\nvoid check_packet_status()\r\n{\r\n    unsigned char pollingFinished = (millis() - previousPolling) > polling;\r\n\r\n    if (messageOkFlag && pollingFinished) { // if a valid message was recieved and the polling delay has expired clear the flag\r\n        messageOkFlag = 0;\r\n        packet->successful_requests++; // transaction sent successfully\r\n        packet->retries = 0; // if a request was successful reset the retry counter\r\n        transmission_ready_Flag = 1;\r\n    }\r\n\r\n    // if an error message was recieved and the polling delay has expired clear the flag\r\n    if (messageErrFlag && pollingFinished) {\r\n        messageErrFlag = 0; // clear error flag\r\n        packet->retries++;\r\n        transmission_ready_Flag = 1;\r\n    }\r\n\r\n    // if the timeout delay has past clear the slot number for next request\r\n    if (!transmission_ready_Flag && ((millis() - previousTimeout) > timeout)) {\r\n        packet->timeout++;\r\n        packet->retries++;\r\n        transmission_ready_Flag = 1;\r\n    }\r\n\r\n    // if the number of retries have reached the max number of retries\r\n    // allowable, stop requesting the specific packet\r\n    if (packet->retries == retry_count) {\r\n        packet->connection = 0;\r\n        packet->retries = 0;\r\n    }\r\n\r\n    if (transmission_ready_Flag) {\r\n        // update the total_errors atribute of the\r\n        // packet before requesting a new one\r\n        packet->total_errors = packet->timeout +\r\n                               packet->incorrect_id_returned +\r\n                               packet->incorrect_function_returned +\r\n                               packet->incorrect_bytes_returned +\r\n                               packet->checksum_failed +\r\n                               packet->buffer_errors +\r\n                               packet->illegal_function +\r\n                               packet->illegal_data_address +\r\n                               packet->illegal_data_value;\r\n    }\r\n}\r\n\r\nvoid check_F3_data(unsigned char buffer)\r\n{\r\n    unsigned char no_of_registers = packet->no_of_registers;\r\n    unsigned char no_of_bytes = no_of_registers * 2;\r\n    if (frame[2] == no_of_bytes) { // check number of bytes returned\r\n        // combine the crc Low & High bytes\r\n        unsigned int recieved_crc = ((frame[buffer - 2] << 8) | frame[buffer - 1]);\r\n        unsigned int calculated_crc = calculateCRC(buffer - 2);\r\n\r\n        if (calculated_crc == recieved_crc) { // verify checksum\r\n            unsigned char index = 3;\r\n            for (unsigned char i = 0; i < no_of_registers; i++) {\r\n                // start at the 4th element in the recieveFrame and combine the Lo byte\r\n                packet->register_array[i] = (frame[index] << 8) | frame[index + 1];\r\n                index += 2;\r\n            }\r\n            messageOkFlag = 1; // message successful\r\n        } else { // checksum failed\r\n            packet->checksum_failed++;\r\n            messageErrFlag = 1; // set an error\r\n        }\r\n\r\n        // start the polling delay for messageOkFlag & messageErrFlag\r\n        previousPolling = millis();\r\n    } else { // incorrect number of bytes returned\r\n        packet->incorrect_bytes_returned++;\r\n        messageErrFlag = 1; // set an error\r\n        previousPolling = millis(); // start the polling delay\r\n    }\r\n}\r\n\r\nvoid check_F16_data()\r\n{\r\n    unsigned int recieved_address = ((frame[2] << 8) | frame[3]);\r\n    unsigned int recieved_registers = ((frame[4] << 8) | frame[5]);\r\n    unsigned int recieved_crc = ((frame[6] << 8) | frame[7]); // combine the crc Low & High bytes\r\n    unsigned int calculated_crc = calculateCRC(6); // only the first 6 bytes are used for crc calculation\r\n\r\n    // check the whole packet\r\n    if (recieved_address == packet->address &&\r\n        recieved_registers == packet->no_of_registers &&\r\n        recieved_crc == calculated_crc)\r\n        messageOkFlag = 1; // message successful\r\n    else {\r\n        packet->checksum_failed++;\r\n        messageErrFlag = 1;\r\n    }\r\n\r\n    // start the polling delay for messageOkFlag & messageErrFlag\r\n    previousPolling = millis();\r\n}\r\n\r\n// get the serial data from the buffer\r\nunsigned char getData()\r\n{\r\n    unsigned char buffer = 0;\r\n    unsigned char overflowFlag = 0;\r\n\r\n    while (Serial.available()) {\r\n        // The maximum number of bytes is limited to the serial buffer size of 128 bytes\r\n        // If more bytes is received than the BUFFER_SIZE the overflow flag will be set and the\r\n        // serial buffer will be red untill all the data is cleared from the receive buffer,\r\n        // while the slave is still responding.\r\n        if (overflowFlag)\r\n            Serial.read();\r\n        else {\r\n            if (buffer == BUFFER_SIZE)\r\n                overflowFlag = 1;\r\n\r\n            frame[buffer] = Serial.read();\r\n            buffer++;\r\n        }\r\n\r\n        delayMicroseconds(T1_5); // inter character time out\r\n    }\r\n\r\n    // The minimum buffer size from a slave can be an exception response of 5 bytes\r\n    // If the buffer was partialy filled clear the buffer.\r\n    // The maximum number of bytes in a modbus packet is 256 bytes.\r\n    // The serial buffer limits this to 128 bytes.\r\n    // If the buffer overflows than clear the buffer and set\r\n    // a packet error.\r\n    if ((buffer > 0 && buffer < 5) || overflowFlag) {\r\n        buffer = 0;\r\n        packet->buffer_errors++;\r\n        messageErrFlag = 1; // set an error\r\n        previousPolling = millis(); // start the polling delay\r\n    }\r\n\r\n    return buffer;\r\n}\r\n\r\nvoid modbus_configure(long baud, unsigned int _timeout, unsigned int _polling,\r\n                      unsigned char _retry_count, unsigned char _TxEnablePin,\r\n                      Packet* _packet, unsigned int _total_no_of_packets)\r\n{\r\n    Serial.begin(baud);\r\n\r\n    if (_TxEnablePin > 1) {\r\n        // pin 0 & pin 1 are reserved for RX/TX. To disable set _TxEnablePin < 2\r\n        TxEnablePin = _TxEnablePin;\r\n        pinMode(TxEnablePin, OUTPUT);\r\n        digitalWrite(TxEnablePin, LOW);\r\n    }\r\n\r\n    // Modbus states that a baud rate higher than 19200 must use a fixed 750 us\r\n    // for inter character time out and 1.75 ms for a frame delay.\r\n    // For baud rates below 19200 the timeing is more critical and has to be calculated.\r\n    // E.g. 9600 baud in a 10 bit packet is 960 characters per second\r\n    // In milliseconds this will be 960characters per 1000ms. So for 1 character\r\n    // 1000ms/960characters is 1.04167ms per character and finaly modbus states an\r\n    // intercharacter must be 1.5T or 1.5 times longer than a normal character and thus\r\n    // 1.5T = 1.04167ms * 1.5 = 1.5625ms. A frame delay is 3.5T.\r\n\r\n    if (baud > 19200) {\r\n        T1_5 = 750;\r\n        T3_5 = 1750;\r\n    } else {\r\n        T1_5 = 15000000/baud; // 1T * 1.5 = T1.5\r\n        T3_5 = 35000000/baud; // 1T * 3.5 = T3.5\r\n    }\r\n\r\n    // initialize connection status of each packet\r\n    for (unsigned char i = 0; i < _total_no_of_packets; i++) {\r\n        _packet->connection = 1;\r\n        _packet++;\r\n    }\r\n\r\n    // initialize\r\n    transmission_ready_Flag = 1;\r\n    messageOkFlag = 0;\r\n    messageErrFlag = 0;\r\n    timeout = _timeout;\r\n    polling = _polling;\r\n    retry_count = _retry_count;\r\n    TxEnablePin = _TxEnablePin;\r\n    total_no_of_packets = _total_no_of_packets;\r\n    previousTimeout = 0;\r\n    previousPolling = 0;\r\n}\r\n\r\nunsigned int calculateCRC(unsigned char bufferSize)\r\n{\r\n    unsigned int temp, temp2, flag;\r\n    temp = 0xFFFF;\r\n    for (unsigned char i = 0; i < bufferSize; i++) {\r\n        temp = temp ^ frame[i];\r\n        for (unsigned char j = 1; j <= 8; j++) {\r\n            flag = temp & 0x0001;\r\n            temp >>= 1;\r\n            if (flag)\r\n                temp ^= 0xA001;\r\n        }\r\n    }\r\n    // Reverse byte order.\r\n    temp2 = temp >> 8;\r\n    temp = (temp << 8) | temp2;\r\n    temp &= 0xFFFF;\r\n    return temp; // the returned value is already swopped - crcLo byte is first & crcHi byte is last\r\n}\r\n\r\nvoid sendPacket(unsigned char bufferSize)\r\n{\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, HIGH);\r\n\r\n    for (unsigned char i = 0; i < bufferSize; i++)\r\n        Serial.write(frame[i]);\r\n\r\n    Serial.flush();\r\n\r\n    // allow a frame delay to indicate end of transmission\r\n    delayMicroseconds(T3_5);\r\n\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, LOW);\r\n\r\n    previousTimeout = millis(); // initialize timeout delay\r\n}"
  },
  {
    "path": "SimpleModbusMaster/SimpleModbusMaster.h",
    "content": "#ifndef SIMPLE_MODBUS_MASTER_H\r\n#define SIMPLE_MODBUS_MASTER_H\r\n\r\n/*\r\n  SimpleModbusMaster allows you to communicate\r\n  to any slave using the Modbus RTU protocol.\r\n  \r\n  To communicate with a slave you need to create a\r\n  packet that will contain all the information\r\n  required to communicate to the slave. There are\r\n  numerous counters for easy diagnostic.\r\n  These are variables already implemented in a\r\n  packet. You can set and clear these variables\r\n  as needed.\r\n  \r\n  There are general modbus information counters:\r\n  requests - contains the total requests to a slave\r\n  successful_requests - contains the total successful requests\r\n  total_errors - contains the total errors as a sum\r\n  timeout - contains the total time out errors\r\n  incorrect_id_returned - contains the total incorrect id returned errors\r\n  incorrect_function_returned - contains the total incorrect function returned errors\r\n  incorrect_bytes_returned - contains the total incorrect bytes returned errors\r\n  checksum_failed - contains the total checksum failed errors\r\n  buffer_errors - contains the total buffer errors\r\n  \r\n  And there are modbus specific exception counters:\r\n  illegal_function - contains the total illegal_function errors\r\n  illegal_data_address - contains the total illegal_data_address errors\r\n  illegal_data_value - contains the total illegal_data_value errors\r\n  misc_exceptions - contains the total miscellaneous returned exceptions\r\n  \r\n  And finally there is variable called \"connection\" that\r\n  at any given moment contains the current connection\r\n  status of the packet. If true then the connection is\r\n  active. If false then communication will be stopped\r\n  on this packet untill the programmer sets the connections\r\n  variable to true explicitly. The reason for this is\r\n  because of the time out involved in modbus communication.\r\n  EACH faulty slave that's not communicating will slow down\r\n  communication on the line with the time out value. E.g.\r\n  Using a time out of 1500ms, if you have 10 slaves and 9 of them\r\n  stops communicating the latency burden placed on communication\r\n  will be 1500ms * 9 = 13,5 seconds!!!!\r\n  \r\n  In addition to this when all the packets are scanned and\r\n  all of them have a false connection a value is returned\r\n  from modbus_port() to inform you something is wrong with\r\n  the port. This is most likely to happen when there is\r\n  something physically wrong with the RS485 line.\r\n  This is only for information. You have to explicitly set\r\n  each packets connection attribute to false.\r\n  Packets scanning and communication will automatically\r\n  revert to normal.\r\n  \r\n  All the error checking, updating and communication multitasking\r\n  takes place in the background!\r\n  \r\n  In general to communicate with to a slave using modbus\r\n  RTU you will request information using the specific\r\n  slave id, the function request, the starting address\r\n  and lastly the number of registers to request.\r\n  Function 3 & 16 are supported. In addition to\r\n  this broadcasting (id = 0) is supported for function 16.\r\n  Constants are provided for:\r\n  Function 3 -  READ_HOLDING_REGISTERS\r\n  Function 16 - PRESET_MULTIPLE_REGISTERS\r\n  \r\n      Note:\r\n  The Arduino serial ring buffer is 128 bytes or 64 registers.\r\n  Most of the time you will connect the arduino to a master via serial\r\n  using a MAX485 or similar.\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 122 bytes or 61 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  118 bytes or 59 registers.\r\n  \r\n  Using the FTDI USB to Serial converter the maximum bytes you can send is limited\r\n  to its internal buffer which is 60 bytes or 30 unsigned int registers.\r\n  \r\n  Thus:\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 54 bytes or 27 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  50 bytes or 25 registers.\r\n  \r\n  Since it is assumed that you will mostly use the Arduino to connect to a\r\n  master without using a USB to Serial converter the internal buffer is set\r\n  the same as the Arduino Serial ring buffer which is 128 bytes.\r\n*/\r\n\r\n#include \"Arduino.h\"\r\n\r\n#define READ_HOLDING_REGISTERS 3\r\n#define\tPRESET_MULTIPLE_REGISTERS 16\r\n\r\ntypedef struct {\r\n    // specific packet info\r\n    unsigned char id;\r\n    unsigned char function;\r\n    unsigned int address;\r\n    unsigned int no_of_registers;\r\n    unsigned int* register_array;\r\n\r\n    // modbus information counters\r\n    unsigned int requests;\r\n    unsigned int successful_requests;\r\n    unsigned long total_errors;\r\n    unsigned int retries;\r\n    unsigned int timeout;\r\n    unsigned int incorrect_id_returned;\r\n    unsigned int incorrect_function_returned;\r\n    unsigned int incorrect_bytes_returned;\r\n    unsigned int checksum_failed;\r\n    unsigned int buffer_errors;\r\n\r\n    // modbus specific exception counters\r\n    unsigned int illegal_function;\r\n    unsigned int illegal_data_address;\r\n    unsigned int illegal_data_value;\r\n    unsigned char misc_exceptions;\r\n\r\n    // connection status of packet\r\n    unsigned char connection;\r\n\r\n} Packet;\r\n\r\ntypedef Packet* packetPointer;\r\n\r\n// function definitions\r\nunsigned int modbus_update(Packet* packets);\r\nvoid modbus_configure(long baud, unsigned int _timeout, unsigned int _polling,\r\n                      unsigned char _retry_count, unsigned char _TxEnablePin,\r\n                      Packet* packets, unsigned int _total_no_of_packets);\r\n\r\n#endif\r\n"
  },
  {
    "path": "SimpleModbusMaster/examples/SimpleModbusMasterExample/SimpleModbusMasterExample.ino",
    "content": "#include <SimpleModbusMaster.h>\n\n/* To communicate with a slave you need to create a\n   packet that will contain all the information\n   required to communicate to that slave.\n\n   There are numerous counters for easy diagnostic.\n   These are variables already implemented in a\n   packet. You can set and clear these variables\n   as needed.\n\n   There are general modbus information counters:\n   requests - contains the total requests to a slave\n   successful_requests - contains the total successful requests\n   total_errors - contains the total errors as a sum\n   timeout - contains the total time out errors\n   incorrect_id_returned - contains the total incorrect id returned errors\n   incorrect_function_returned - contains the total incorrect function returned errors\n   incorrect_bytes_returned - contains the total incorrect bytes returned errors\n   checksum_failed - contains the total checksum failed errors\n   buffer_errors - contains the total buffer errors\n\n   And there are modbus specific exception counters:\n   illegal_function - contains the total illegal function errors\n   illegal_data_address - contains the total illegal data_address errors\n   illegal_data_value - contains the total illegal data value errors\n   misc_exceptions - contains the total miscellaneous returned exceptions\n\n   And finally there is a variable called \"connection\" that\n   at any given moment contains the current connection\n   status of the packet. If true then the connection is\n   active if false then communication will be stopped\n   on this packet untill the programmer sets the \"connection\"\n   variable to true explicitly. The reason for this is\n   because of the time out involved in modbus communication.\n   EACH faulty slave that's not communicating will slow down\n   communication on the line with the time out value. E.g.\n   Using a time out of 1500ms, if you have 10 slaves and 9 of them\n   stops communicating the latency burden placed on communication\n   will be 1500ms * 9 = 13,5 seconds!!!!\n\n   modbus_update() returns the previously scanned false connection.\n   You can use this as the index to your packet array to find out\n   if the connection has failed in that packet and then react to it.\n   You can then try to re-enable the connecion by setting the\n   packet->connection attribute to true.\n   The index will only be available for one loop cycle, after that\n   it's cleared and ready to return the next false connection index\n   if there is one else it will return the packet array size indicating\n   everything is ok.\n\n   All the error checking, updating and communication multitasking\n   takes place in the background!\n\n   In general to communicate with to a slave using modbus\n   RTU you will request information using the specific\n   slave id, the function request, the starting address\n   and lastly the number of registers to request.\n   Function 3 and 16 are supported. In addition to\n   this broadcasting (id = 0) is supported on function 16.\n   Constants are provided for:\n   Function 3 -  READ_HOLDING_REGISTERS\n   Function 16 - PRESET_MULTIPLE_REGISTERS\n\n   The example sketch will read a packet consisting\n   of 9 registers from address 0 using function 3 from\n   the SimpleModbusSlave example and then write\n   another packet containing a value to toggle the led.s\n*/\n\n// led to indicate that a communication error is present\n#define connection_error_led 13\n\n//////////////////// Port information ///////////////////\n#define baud 115200\n#define timeout 1000\n#define polling 200 // the scan rate\n\n// If the packets internal retry register matches\n// the set retry count then communication is stopped\n// on that packet. To re-enable the packet you must\n// set the \"connection\" variable to true.\n#define retry_count 10\n\n// used to toggle the receive/transmit pin on the driver\n#define TxEnablePin 2\n\n// This is the easiest way to create new packets\n// Add as many as you want. TOTAL_NO_OF_PACKETS\n// is automatically updated.\nenum {\n    PACKET1,\n    PACKET2,\n    // leave this last entry\n    TOTAL_NO_OF_PACKETS\n};\n\n// Create an array of Packets for modbus_update()\nPacket packets[TOTAL_NO_OF_PACKETS];\n\n// Create a packetPointer to access each packet\n// individually. This is not required you can access\n// the array explicitly. E.g. packets[PACKET1].id = 2;\n// This does become tedious though...\npacketPointer packet1 = &packets[PACKET1];\npacketPointer packet2 = &packets[PACKET2];\n\n// The data from the PLC will be stored\n// in the regs array\nunsigned int regs[9];\nunsigned int write_regs[1];\n\nunsigned long last_toggle = 0;\n\nvoid setup()\n{\n    // read 3 registers starting at address 0\n    packet1->id = 2;\n    packet1->function = READ_HOLDING_REGISTERS;\n    packet1->address = 0;\n    packet1->no_of_registers = 9;\n    packet1->register_array = regs;\n\n    // write the 9 registers to the PLC starting at address 3\n    packet2->id = 2;\n    packet2->function = PRESET_MULTIPLE_REGISTERS;\n    packet2->address = 6;\n    packet2->no_of_registers = 1;\n    packet2->register_array = write_regs;\n    \n    // Initialize communication settings etc...\n    modbus_configure(baud, timeout, polling, retry_count, TxEnablePin, packets, TOTAL_NO_OF_PACKETS);\n\n    pinMode(connection_error_led, OUTPUT);\n}\n\nvoid loop()\n{\n    unsigned int connection_status = modbus_update(packets);\n\n    if (millis() - last_toggle > 1000) {\n        last_toggle = millis();\n        write_regs[0] = led_on;\n    }\n\n    if (connection_status != TOTAL_NO_OF_PACKETS) {\n        digitalWrite(connection_error_led, HIGH);\n        // You could re-enable the connection by:\n        //packets[connection_status].connection = true;\n    } else {\n        digitalWrite(connection_error_led, LOW);\n    }\n}\n"
  },
  {
    "path": "SimpleModbusMaster/keywords.txt",
    "content": "Packet\tKEYWORD1\r\npacketPointer\tKEYWORD1\r\nmodbus_configure\tKEYWORD2\r\nmodbus_port\tKEYWORD2\r\n\r\n###### Constants ######\r\nREAD_HOLDING_REGISTERS\tLITERAL1\r\nPRESET_MULTIPLE_REGISTERS\tLITERAL1\r\n"
  },
  {
    "path": "SimpleModbusMasterSoftwareSerial/SimpleModbusMasterSoftwareSerial.cpp",
    "content": "#include \"SimpleModbusMasterSoftwareSerial.h\"\r\n\r\n#define BUFFER_SIZE 128\r\n\r\n// modbus specific exceptions\r\n#define ILLEGAL_FUNCTION 1\r\n#define ILLEGAL_DATA_ADDRESS 2\r\n#define ILLEGAL_DATA_VALUE 3\r\n\r\nunsigned char transmission_ready_Flag;\r\nunsigned char messageOkFlag, messageErrFlag;\r\nunsigned char retry_count;\r\nunsigned char TxEnablePin;\r\n// frame[] is used to recieve and transmit packages. \r\n// The maximum number of bytes in a modbus packet is 256 bytes\r\n// This is limited to the serial buffer of 128 bytes\r\nunsigned char frame[BUFFER_SIZE]; \r\nunsigned int timeout, polling;\r\nunsigned int T1_5; // inter character time out in microseconds\r\nunsigned int T3_5; // frame delay in microseconds\r\nunsigned long previousTimeout, previousPolling;\r\nunsigned int total_no_of_packets;\r\nPacket* packet; // current packet\r\nSoftwareSerial* _port;\r\n\r\n// function definitions\r\nvoid constructPacket();\r\nvoid checkResponse();\r\nvoid check_F3_data(unsigned char buffer);\r\nvoid check_F16_data();\r\nunsigned char getData();\r\nvoid check_packet_status();\r\nunsigned int calculateCRC(unsigned char bufferSize);\r\nvoid sendPacket(unsigned char bufferSize);\r\n\r\n// use this function create packets\r\nvoid modbus_packet_init(Packet *packet, unsigned char id, unsigned char function, unsigned int dest_register, unsigned int num_registers, unsigned int *reg) {\r\n  packet->id = id;\r\n  packet->function = function;\r\n  packet->address = dest_register; // first slave register to write to\r\n  packet->no_of_registers = num_registers; // number of registers to write\r\n  packet->register_array = reg; // first master register to read from\r\n}\r\n\r\nunsigned int modbus_update(Packet* packets) \r\n{\r\n  // Initialize the connection_status variable to the\r\n  // total_no_of_packets. This value cannot be used as \r\n  // an index (and normally you won't). Returning this \r\n  // value to the main skecth informs the user that the \r\n  // previously scanned packet has no connection error.\r\n  unsigned int connection_status = total_no_of_packets;\r\n\r\n  if (transmission_ready_Flag) \r\n  {\r\n    static unsigned int packet_index;  \r\n    unsigned int failed_connections = 0;\r\n    unsigned char current_connection;\r\n    do\r\n    {    \r\n      if (packet_index == total_no_of_packets) // wrap around to the beginning\r\n        packet_index = 0;\r\n\r\n      // proceed to the next packet\r\n      packet = &packets[packet_index];\r\n      // get the current connection status\r\n      current_connection = packet->connection;\r\n\r\n      if (!current_connection)\r\n      {\r\n        connection_status = packet_index;\r\n        // If all the connection attributes are false return\r\n        // immediately to the main sketch\r\n        if (++failed_connections == total_no_of_packets)\r\n          return connection_status;\r\n      }\r\n      packet_index++;\r\n\r\n    }while (!current_connection); // while a packet has no connection get the next one\r\n    constructPacket();\r\n  }\r\n  checkResponse();\r\n  check_packet_status();  \r\n\r\n  return connection_status; \r\n}\r\n  \r\nvoid constructPacket()\r\n{   \r\n  unsigned int crc16;\r\n\r\n  transmission_ready_Flag = 0; // disable the next transmission\r\n  packet->requests++;\r\n  frame[0] = packet->id;\r\n  frame[1] = packet->function;\r\n  frame[2] = packet->address >> 8; // address Hi\r\n  frame[3] = packet->address & 0xFF; // address Lo\r\n  frame[4] = packet->no_of_registers >> 8; // no_of_registers Hi\r\n  frame[5] = packet->no_of_registers & 0xFF; // no_of_registers Lo\r\n\r\n  // construct the frame according to the modbus function  \r\n  if (packet->function == PRESET_MULTIPLE_REGISTERS) \r\n  {\r\n    unsigned char no_of_bytes = packet->no_of_registers * 2;\r\n    unsigned char frameSize = 9 + no_of_bytes; // first 7 bytes of the array + 2 bytes CRC+ noOfBytes\r\n    frame[6] = no_of_bytes; // number of bytes\r\n    unsigned char index = 7; // user data starts at index 7\r\n    unsigned int temp;\r\n    // should be unsigned int but we will never send more than 255 registers in 1 packet\r\n    unsigned char no_of_registers = packet->no_of_registers;\r\n    for (unsigned char i = 0; i < no_of_registers; i++)\r\n    {\r\n      temp = packet->register_array[i]; // get the data\r\n      frame[index] = temp >> 8;\r\n      index++;\r\n      frame[index] = temp & 0xFF;\r\n      index++;\r\n    }\r\n    crc16 = calculateCRC(frameSize - 2);  \r\n    frame[frameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n    frame[frameSize - 1] = crc16 & 0xFF;\r\n    sendPacket(frameSize);\r\n \r\n    if (packet->id == 0) // check broadcast id \r\n    {\r\n      messageOkFlag = 1; // message successful, there will be no response on a broadcast\r\n      previousPolling = millis(); // start the polling delay\r\n    }\r\n  }\r\n  else // READ_HOLDING_REGISTERS is assumed\r\n  {\r\n    crc16 = calculateCRC(6); // the first 6 bytes of the frame is used in the CRC calculation\r\n    frame[6] = crc16 >> 8; // crc Lo\r\n    frame[7] = crc16 & 0xFF; // crc Hi\r\n    sendPacket(8); // a request with function 3, 4 & 6 is always 8 bytes in size \r\n  }\r\n}\r\n\r\nvoid checkResponse()\r\n{\r\n  if (!messageOkFlag && !messageErrFlag) // check for response\r\n  {\r\n    unsigned char buffer = getData();\r\n \r\n    if (buffer > 0) // if there's something in the buffer continue\r\n    {\r\n      if (frame[0] == packet->id) // check id returned\r\n      {\r\n        // to indicate an exception response a slave will 'OR' \r\n        // the requested function with 0x80 \r\n        if ((frame[1] & 0x80) == 0x80) // exctract 0x80\r\n        {\r\n          // the third byte in the exception response packet is the actual exception\r\n          switch (frame[2])\r\n          {\r\n            case ILLEGAL_FUNCTION: packet->illegal_function++; break;\r\n            case ILLEGAL_DATA_ADDRESS: packet->illegal_data_address++; break;\r\n            case ILLEGAL_DATA_VALUE: packet->illegal_data_value++; break;\r\n            default: packet->misc_exceptions++;\r\n          }\r\n          messageErrFlag = 1; // set an error\r\n          previousPolling = millis(); // start the polling delay\r\n        }\r\n        else // the response is valid\r\n        {\r\n          if (frame[1] == packet->function) // check function number returned\r\n          {\r\n            // receive the frame according to the modbus function\r\n            if (packet->function == PRESET_MULTIPLE_REGISTERS) \r\n              check_F16_data();\r\n            else // READ_HOLDING_REGISTERS is assumed\r\n              check_F3_data(buffer);\r\n          }\r\n          else // incorrect function number returned\r\n          {\r\n            packet->incorrect_function_returned++; \r\n            messageErrFlag = 1; // set an error\r\n            previousPolling = millis(); // start the polling delay\r\n          } \r\n        } // check exception response\r\n      } \r\n      else // incorrect id returned\r\n      {\r\n        packet->incorrect_id_returned++; \r\n        messageErrFlag = 1; // set an error\r\n        previousPolling = millis(); // start the polling delay\r\n      }\r\n    } // check buffer\r\n  } // check message booleans\r\n}\r\n\r\n// checks the time out and polling delay and if a message has been recieved succesfully \r\nvoid check_packet_status()\r\n{\r\n  unsigned char pollingFinished = (millis() - previousPolling) > polling;\r\n\r\n  // if a valid message was recieved and the polling delay has expired clear the flag\r\n  if (messageOkFlag && pollingFinished)\r\n  {\r\n    messageOkFlag = 0;\r\n    packet->successful_requests++; // transaction sent successfully\r\n    packet->retries = 0; // if a request was successful reset the retry counter\r\n    transmission_ready_Flag = 1; \r\n  }  \r\n\r\n  // if an error message was recieved and the polling delay has expired clear the flag\r\n  if (messageErrFlag && pollingFinished) \r\n  {\r\n    messageErrFlag = 0; // clear error flag \r\n    packet->retries++;\r\n    transmission_ready_Flag = 1;\r\n  } \r\n \r\n  // if the timeout delay has past clear the slot number for next request\r\n  if (!transmission_ready_Flag && ((millis() - previousTimeout) > timeout)) \r\n  {\r\n    packet->timeout++;\r\n    packet->retries++;\r\n    transmission_ready_Flag = 1; \r\n  }\r\n\r\n  // if the number of retries have reached the max number of retries \r\n  // allowable, stop requesting the specific packet\r\n  if (packet->retries == retry_count)\r\n  {\r\n    packet->connection = 0;\r\n    packet->retries = 0;\r\n  }\r\n\r\n  if (transmission_ready_Flag)\r\n  {\r\n    // update the total_errors atribute of the \r\n    // packet before requesting a new one\r\n    packet->total_errors = packet->timeout + \r\n                           packet->incorrect_id_returned +\r\n                           packet->incorrect_function_returned +\r\n                           packet->incorrect_bytes_returned +\r\n                           packet->checksum_failed +\r\n                           packet->buffer_errors +\r\n                           packet->illegal_function +\r\n                           packet->illegal_data_address +\r\n                           packet->illegal_data_value;\r\n  }\r\n}\r\n\r\nvoid check_F3_data(unsigned char buffer)\r\n{\r\n  unsigned char no_of_registers = packet->no_of_registers;\r\n  unsigned char no_of_bytes = no_of_registers * 2;\r\n  if (frame[2] == no_of_bytes) // check number of bytes returned\r\n  {\r\n    // combine the crc Low & High bytes\r\n    unsigned int recieved_crc = ((frame[buffer - 2] << 8) | frame[buffer - 1]); \r\n    unsigned int calculated_crc = calculateCRC(buffer - 2);\r\n        \r\n    if (calculated_crc == recieved_crc) // verify checksum\r\n    {\r\n      unsigned char index = 3;\r\n      for (unsigned char i = 0; i < no_of_registers; i++)\r\n      {\r\n        // start at the 4th element in the recieveFrame and combine the Lo byte \r\n        packet->register_array[i] = (frame[index] << 8) | frame[index + 1]; \r\n        index += 2;\r\n      }\r\n      messageOkFlag = 1; // message successful\r\n    }\r\n    else // checksum failed\r\n    {\r\n      packet->checksum_failed++; \r\n      messageErrFlag = 1; // set an error\r\n    }\r\n      \r\n    // start the polling delay for messageOkFlag & messageErrFlag\r\n    previousPolling = millis(); \r\n  }\r\n  else // incorrect number of bytes returned  \r\n  {\r\n    packet->incorrect_bytes_returned++; \r\n    messageErrFlag = 1; // set an error\r\n    previousPolling = millis(); // start the polling delay\r\n  }                       \r\n}\r\n\r\nvoid check_F16_data()\r\n{\r\n  unsigned int recieved_address = ((frame[2] << 8) | frame[3]);\r\n  unsigned int recieved_registers = ((frame[4] << 8) | frame[5]); \r\n  unsigned int recieved_crc = ((frame[6] << 8) | frame[7]); // combine the crc Low & High bytes\r\n  unsigned int calculated_crc = calculateCRC(6); // only the first 6 bytes are used for crc calculation\r\n\r\n  // check the whole packet    \r\n  if (recieved_address == packet->address && \r\n      recieved_registers == packet->no_of_registers && \r\n      recieved_crc == calculated_crc)\r\n      messageOkFlag = 1; // message successful\r\n  else\r\n  {\r\n    packet->checksum_failed++; \r\n    messageErrFlag = 1;\r\n  }\r\n\r\n  // start the polling delay for messageOkFlag & messageErrFlag\r\n  previousPolling = millis();\r\n}\r\n\r\n// get the serial data from the buffer\r\nunsigned char getData()\r\n{\r\n  unsigned char buffer = 0;\r\n  unsigned char overflowFlag = 0;\r\n\r\n  while ((*_port).available())\r\n  {\r\n    // The maximum number of bytes is limited to the serial buffer size of 128 bytes\r\n    // If more bytes is received than the BUFFER_SIZE the overflow flag will be set and the \r\n    // serial buffer will be red untill all the data is cleared from the receive buffer,\r\n    // while the slave is still responding.\r\n    if (overflowFlag) \r\n      (*_port).read();\r\n    else\r\n    {\r\n      if (buffer == BUFFER_SIZE)\r\n        overflowFlag = 1;\r\n        \r\n      frame[buffer] = (*_port).read();\r\n      buffer++;\r\n    }\r\n\r\n    delayMicroseconds(T1_5); // inter character time out\r\n  }\r\n\r\n  // The minimum buffer size from a slave can be an exception response of 5 bytes \r\n  // If the buffer was partialy filled clear the buffer.\r\n  // The maximum number of bytes in a modbus packet is 256 bytes.\r\n  // The serial buffer limits this to 128 bytes.\r\n  // If the buffer overflows than clear the buffer and set\r\n  // a packet error.\r\n  if ((buffer > 0 && buffer < 5) || overflowFlag)\r\n  {\r\n    buffer = 0;\r\n    packet->buffer_errors++; \r\n    messageErrFlag = 1; // set an error\r\n    previousPolling = millis(); // start the polling delay \r\n  }\r\n\r\n  return buffer;\r\n}\r\n\r\nvoid modbus_configure(SoftwareSerial* comPort, long baud,\r\n                    unsigned int _timeout, unsigned int _polling, \r\n                    unsigned char _retry_count, unsigned char _TxEnablePin, \r\n                    Packet* _packet, unsigned int _total_no_of_packets)\r\n{\r\n  _port = comPort;\r\n  (*_port).begin(baud);\r\n  // pin 0 & pin 1 are reserved for RX/TX. To disable set _TxEnablePin < 2\r\n  if (_TxEnablePin > 1)\r\n  {\r\n    TxEnablePin = _TxEnablePin; \r\n    pinMode(TxEnablePin, OUTPUT);\r\n    digitalWrite(TxEnablePin, LOW);\r\n  }\r\n\r\n  // Modbus states that a baud rate higher than 19200 must use a fixed 750 us \r\n  // for inter character time out and 1.75 ms for a frame delay.\r\n  // For baud rates below 19200 the timeing is more critical and has to be calculated.\r\n  // E.g. 9600 baud in a 10 bit packet is 960 characters per second\r\n  // In milliseconds this will be 960characters per 1000ms. So for 1 character\r\n  // 1000ms/960characters is 1.04167ms per character and finaly modbus states an\r\n  // intercharacter must be 1.5T or 1.5 times longer than a normal character and thus\r\n  // 1.5T = 1.04167ms * 1.5 = 1.5625ms. A frame delay is 3.5T.\r\n\r\n  if (baud > 19200)\r\n  {\r\n    T1_5 = 750; \r\n    T3_5 = 1750; \r\n  }\r\n  else \r\n  {\r\n    T1_5 = 15000000/baud; // 1T * 1.5 = T1.5\r\n    T3_5 = 35000000/baud; // 1T * 3.5 = T3.5\r\n  }\r\n\r\n  // initialize connection status of each packet\r\n  for (unsigned char i = 0; i < _total_no_of_packets; i++)\r\n  {\r\n    _packet->connection = 1;\r\n    _packet++;\r\n  }\r\n\r\n  // initialize\r\n  transmission_ready_Flag = 1;\r\n  messageOkFlag = 0; \r\n  messageErrFlag = 0;\r\n  timeout = _timeout;\r\n  polling = _polling;\r\n  retry_count = _retry_count;\r\n  TxEnablePin = _TxEnablePin;\r\n  total_no_of_packets = _total_no_of_packets;\r\n  previousTimeout = 0; \r\n  previousPolling = 0; \r\n} \r\n\r\nunsigned int calculateCRC(unsigned char bufferSize) \r\n{\r\n  unsigned int temp, temp2, flag;\r\n  temp = 0xFFFF;\r\n  for (unsigned char i = 0; i < bufferSize; i++)\r\n  {\r\n    temp = temp ^ frame[i];\r\n    for (unsigned char j = 1; j <= 8; j++)\r\n    {\r\n      flag = temp & 0x0001;\r\n      temp >>= 1;\r\n      if (flag)\r\n        temp ^= 0xA001;\r\n    }\r\n  }\r\n  // Reverse byte order. \r\n  temp2 = temp >> 8;\r\n  temp = (temp << 8) | temp2;\r\n  temp &= 0xFFFF;\r\n  return temp; // the returned value is already swopped - crcLo byte is first & crcHi byte is last\r\n}\r\n\r\nvoid sendPacket(unsigned char bufferSize)\r\n{\r\n  if (TxEnablePin > 1)\r\n    digitalWrite(TxEnablePin, HIGH);\r\n\r\n  for (unsigned char i = 0; i < bufferSize; i++)\r\n    (*_port).write(frame[i]);\r\n\r\n  // finish writing buffer to the wire, only works for HardwareSerial\r\n  (*_port).flush();\r\n  // allow a frame delay to indicate end of transmission\r\n  delayMicroseconds(T3_5); \r\n\r\n  if (TxEnablePin > 1)\r\n    digitalWrite(TxEnablePin, LOW);\r\n\r\n  previousTimeout = millis(); // initialize timeout delay  \r\n}\r\n"
  },
  {
    "path": "SimpleModbusMasterSoftwareSerial/SimpleModbusMasterSoftwareSerial.h",
    "content": "#ifndef SIMPLE_MODBUS_MASTER_H\r\n#define SIMPLE_MODBUS_MASTER_H\r\n\r\n/* \r\n   SoftwareSerial has limitations and is NOT SUPPORTED ON ALL PINS.\r\n\r\n   SimpleModbusMaster allows you to communicate\r\n   to any slave using the Modbus RTU protocol.\r\n\r\n   To communicate with a slave you need to create a \r\n   packet that will contain all the information\r\n   required to communicate to the slave. There are \r\n   numerous counters for easy diagnostic.\r\n   These are variables already implemented in a \r\n   packet. You can set and clear these variables\r\n   as needed.\r\n\r\n   There are general modbus information counters:\r\n   requests - contains the total requests to a slave\r\n   successful_requests - contains the total successful requests\r\n   total_errors - contains the total errors as a sum\r\n   timeout - contains the total time out errors\r\n   incorrect_id_returned - contains the total incorrect id returned errors\r\n   incorrect_function_returned - contains the total incorrect function returned errors\r\n   incorrect_bytes_returned - contains the total incorrect bytes returned errors\r\n   checksum_failed - contains the total checksum failed errors\r\n   buffer_errors - contains the total buffer errors\r\n\r\n   And there are modbus specific exception counters:\r\n   illegal_function - contains the total illegal_function errors\r\n   illegal_data_address - contains the total illegal_data_address errors\r\n   illegal_data_value - contains the total illegal_data_value errors\r\n   misc_exceptions - contains the total miscellaneous returned exceptions \r\n\r\n   And finally there is variable called \"connection\" that \r\n   at any given moment contains the current connection \r\n   status of the packet. If true then the connection is \r\n   active. If false then communication will be stopped\r\n   on this packet untill the programmer sets the connections\r\n   variable to true explicitly. The reason for this is \r\n   because of the time out involved in modbus communication.\r\n   EACH faulty slave that's not communicating will slow down\r\n   communication on the line with the time out value. E.g.\r\n   Using a time out of 1500ms, if you have 10 slaves and 9 of them\r\n   stops communicating the latency burden placed on communication\r\n   will be 1500ms * 9 = 13,5 seconds!!!!\r\n\r\n   In addition to this when all the packets are scanned and \r\n   all of them have a false connection a value is returned\r\n   from modbus_port() to inform you something is wrong with \r\n   the port. This is most likely to happen when there is \r\n   something physically wrong with the RS485 line. \r\n   This is only for information. You have to explicitly set \r\n   each packets connection attribute to false. \r\n   Packets scanning and communication will automatically\r\n   revert to normal.\r\n\r\n   All the error checking, updating and communication multitasking\r\n   takes place in the background!\r\n\r\n   In general to communicate with to a slave using modbus\r\n   RTU you will request information using the specific\r\n   slave id, the function request, the starting address\r\n   and lastly the number of registers to request.\r\n   Function 3 & 16 are supported. In addition to\r\n   this broadcasting (id = 0) is supported for function 16.\r\n   Constants are provided for:\r\n   Function 3 -  READ_HOLDING_REGISTERS \r\n   Function 16 - PRESET_MULTIPLE_REGISTERS \r\n\r\n   Note:  \r\n   The Arduino serial ring buffer is 128 bytes or 64 registers.\r\n   Most of the time you will connect the arduino to a master via serial\r\n   using a MAX485 or similar.\r\n\r\n   In a function 3 request the master will attempt to read from your\r\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n   and two BYTES CRC the master can only request 122 bytes or 61 registers.\r\n\r\n   In a function 16 request the master will attempt to write to your \r\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS, \r\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n   118 bytes or 59 registers.\r\n\r\n   Using the FTDI USB to Serial converter the maximum bytes you can send is limited \r\n   to its internal buffer which is 60 bytes or 30 unsigned int registers. \r\n   Thus:\r\n   In a function 3 request the master will attempt to read from your\r\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n   and two BYTES CRC the master can only request 54 bytes or 27 registers.\r\n\r\n   In a function 16 request the master will attempt to write to your \r\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS, \r\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n   50 bytes or 25 registers.\r\n\r\n   Since it is assumed that you will mostly use the Arduino to connect to a \r\n   master without using a USB to Serial converter the internal buffer is set\r\n   the same as the Arduino Serial ring buffer which is 128 bytes.\r\n*/\r\n\r\n#include \"Arduino.h\"\r\n#include \"SoftwareSerial.h\"\r\n\r\n#define READ_HOLDING_REGISTERS 3\r\n#define PRESET_MULTIPLE_REGISTERS 16\r\n\r\ntypedef struct\r\n{\r\n  // specific packet info\r\n  unsigned char id;\r\n  unsigned char function;\r\n  unsigned int address;\r\n  unsigned int no_of_registers; \r\n  unsigned int* register_array;\r\n\r\n  // modbus information counters\r\n  unsigned int requests;\r\n  unsigned int successful_requests;\r\n  unsigned long total_errors;\r\n  unsigned int retries;\r\n  unsigned int timeout;\r\n  unsigned int incorrect_id_returned;\r\n  unsigned int incorrect_function_returned;\r\n  unsigned int incorrect_bytes_returned;\r\n  unsigned int checksum_failed;\r\n  unsigned int buffer_errors;\r\n\r\n  // modbus specific exception counters\r\n  unsigned int illegal_function;\r\n  unsigned int illegal_data_address;\r\n  unsigned int illegal_data_value;\r\n  unsigned char misc_exceptions;\r\n\r\n  // connection status of packet\r\n  unsigned char connection; \r\n}Packet;\r\n\r\ntypedef Packet* packetPointer;\r\n\r\nunsigned int modbus_update(Packet* packets);\r\nvoid modbus_configure(\r\n  SoftwareSerial* comPort,\r\n  long baud,\r\n  unsigned int _timeout,\r\n  unsigned int _polling, \r\n  unsigned char _retry_count,\r\n  unsigned char _TxEnablePin,\r\n  Packet* packets,\r\n  unsigned int _total_no_of_packets);\r\nvoid modbus_packet_init(\r\n  Packet *packet,\r\n  unsigned char id,\r\n  unsigned char function,\r\n  unsigned int dest_register,\r\n  unsigned int num_registers,\r\n  unsigned int *reg);\r\n\r\n#endif\r\n"
  },
  {
    "path": "SimpleModbusSlave/SimpleModbusSlave.cpp",
    "content": "#include \"SimpleModbusSlave.h\"\r\n\r\n#define BUFFER_SIZE 128\r\n\r\n// frame[] is used to recieve and transmit packages.\r\n// The maximum serial ring buffer size is 128\r\nunsigned char frame[BUFFER_SIZE];\r\nunsigned int holdingRegsSize; // size of the register array\r\nunsigned char broadcastFlag;\r\nunsigned char slaveID;\r\nunsigned char function;\r\nunsigned char TxEnablePin;\r\nunsigned int errorCount;\r\nunsigned int T1_5; // inter character time out\r\nunsigned int T3_5; // frame delay\r\n\r\n// function definitions\r\nvoid exceptionResponse(unsigned char exception);\r\nunsigned int calculateCRC(unsigned char bufferSize);\r\nvoid sendPacket(unsigned char bufferSize);\r\n\r\nunsigned int modbus_update(unsigned int *holdingRegs)\r\n{\r\n    unsigned char buffer = 0;\r\n    unsigned char overflow = 0;\r\n\r\n    while (Serial.available()) {\r\n        // The maximum number of bytes is limited to the serial buffer size of 128 bytes\r\n        // If more bytes is received than the BUFFER_SIZE the overflow flag will be set and the\r\n        // serial buffer will be red untill all the data is cleared from the receive buffer.\r\n        if (overflow)\r\n            Serial.read();\r\n        else {\r\n            if (buffer == BUFFER_SIZE)\r\n                overflow = 1;\r\n            frame[buffer] = Serial.read();\r\n            buffer++;\r\n        }\r\n        delayMicroseconds(T1_5); // inter character time out\r\n    }\r\n\r\n    // If an overflow occurred increment the errorCount\r\n    // variable and return to the main sketch without\r\n    // responding to the request i.e. force a timeout\r\n    if (overflow)\r\n        return errorCount++;\r\n\r\n    // The minimum request packet is 8 bytes for function 3 & 16\r\n    if (buffer > 6) {\r\n        unsigned char id = frame[0];\r\n\r\n        broadcastFlag = 0;\r\n\r\n        if (id == 0)\r\n            broadcastFlag = 1;\r\n\r\n        if (id == slaveID || broadcastFlag) { // if the recieved ID matches the slaveID or broadcasting id (0), continue\r\n            unsigned int crc = ((frame[buffer - 2] << 8) | frame[buffer - 1]); // combine the crc Low & High bytes\r\n            if (calculateCRC(buffer - 2) == crc) { // if the calculated crc matches the recieved crc continue\r\n                function = frame[1];\r\n                unsigned int startingAddress = ((frame[2] << 8) | frame[3]); // combine the starting address bytes\r\n                unsigned int no_of_registers = ((frame[4] << 8) | frame[5]); // combine the number of register bytes\r\n                unsigned int maxData = startingAddress + no_of_registers;\r\n                unsigned char index;\r\n                unsigned char address;\r\n                unsigned int crc16;\r\n\r\n                // broadcasting is not supported for function 3\r\n                if (!broadcastFlag && (function == 3)) {\r\n                    if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                        if (maxData <= holdingRegsSize) { // check exception 3 ILLEGAL DATA VALUE\r\n                            unsigned char noOfBytes = no_of_registers * 2;\r\n                            unsigned char responseFrameSize = 5 + noOfBytes; // ID, function, noOfBytes, (dataLo + dataHi) * number of registers, crcLo, crcHi\r\n                            frame[0] = slaveID;\r\n                            frame[1] = function;\r\n                            frame[2] = noOfBytes;\r\n                            address = 3; // PDU starts at the 4th byte\r\n                            unsigned int temp;\r\n\r\n                            for (index = startingAddress; index < maxData; index++) {\r\n                                temp = holdingRegs[index];\r\n                                frame[address] = temp >> 8; // split the register into 2 bytes\r\n                                address++;\r\n                                frame[address] = temp & 0xFF;\r\n                                address++;\r\n                            }\r\n\r\n                            crc16 = calculateCRC(responseFrameSize - 2);\r\n                            frame[responseFrameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n                            frame[responseFrameSize - 1] = crc16 & 0xFF;\r\n                            sendPacket(responseFrameSize);\r\n                        } else\r\n                            exceptionResponse(3); // exception 3 ILLEGAL DATA VALUE\r\n                    } else\r\n                        exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                } else if (function == 6) {\r\n                    if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                        unsigned int startingAddress = ((frame[2] << 8) | frame[3]);\r\n                        unsigned int regStatus = ((frame[4] << 8) | frame[5]);\r\n                        unsigned char responseFrameSize = 8;\r\n\r\n                        holdingRegs[startingAddress] = regStatus;\r\n\r\n                        crc16 = calculateCRC(responseFrameSize - 2);\r\n                        frame[responseFrameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n                        frame[responseFrameSize - 1] = crc16 & 0xFF;\r\n                        sendPacket(responseFrameSize);\r\n                    } else\r\n                        exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                } else if (function == 16) {\r\n                    // check if the recieved number of bytes matches the calculated bytes minus the request bytes\r\n                    // id + function + (2 * address bytes) + (2 * no of register bytes) + byte count + (2 * CRC bytes) = 9 bytes\r\n                    if (frame[6] == (buffer - 9)) {\r\n                        if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                            if (maxData <= holdingRegsSize) { // check exception 3 ILLEGAL DATA VALUE\r\n                                address = 7; // start at the 8th byte in the frame\r\n\r\n                                for (index = startingAddress; index < maxData; index++) {\r\n                                    holdingRegs[index] = ((frame[address] << 8) | frame[address + 1]);\r\n                                    address += 2;\r\n                                }\r\n\r\n                                // only the first 6 bytes are used for CRC calculation\r\n                                crc16 = calculateCRC(6);\r\n                                frame[6] = crc16 >> 8; // split crc into 2 bytes\r\n                                frame[7] = crc16 & 0xFF;\r\n\r\n                                // a function 16 response is an echo of the first 6 bytes from the request + 2 crc bytes\r\n                                if (!broadcastFlag) // don't respond if it's a broadcast message\r\n                                    sendPacket(8);\r\n                            } else\r\n                                exceptionResponse(3); // exception 3 ILLEGAL DATA VALUE\r\n                        } else\r\n                            exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                    } else\r\n                        errorCount++; // corrupted packet\r\n                } else\r\n                    exceptionResponse(1); // exception 1 ILLEGAL FUNCTION\r\n            } else // checksum failed\r\n                errorCount++;\r\n        } // incorrect id\r\n    } else if (buffer > 0 && buffer < 8)\r\n        errorCount++; // corrupted packet\r\n\r\n    return errorCount;\r\n}\r\n\r\nvoid exceptionResponse(unsigned char exception)\r\n{\r\n    errorCount++; // each call to exceptionResponse() will increment the errorCount\r\n    if (!broadcastFlag) { // don't respond if its a broadcast message\r\n        frame[0] = slaveID;\r\n        frame[1] = (function | 0x80); // set the MSB bit high, informs the master of an exception\r\n        frame[2] = exception;\r\n        unsigned int crc16 = calculateCRC(3); // ID, function + 0x80, exception code == 3 bytes\r\n        frame[3] = crc16 >> 8;\r\n        frame[4] = crc16 & 0xFF;\r\n        sendPacket(5); // exception response is always 5 bytes ID, function + 0x80, exception code, 2 bytes crc\r\n    }\r\n}\r\n\r\nvoid modbus_configure(long baud, unsigned char _slaveID, unsigned char _TxEnablePin, unsigned int _holdingRegsSize, unsigned char _lowLatency)\r\n{\r\n    slaveID = _slaveID;\r\n    Serial.begin(baud);\r\n\r\n    if (_TxEnablePin > 1) {\r\n        // pin 0 & pin 1 are reserved for RX/TX. To disable set txenpin < 2\r\n        TxEnablePin = _TxEnablePin;\r\n        pinMode(TxEnablePin, OUTPUT);\r\n        digitalWrite(TxEnablePin, LOW);\r\n    }\r\n\r\n    // Modbus states that a baud rate higher than 19200 must use a fixed 750 us\r\n    // for inter character time out and 1.75 ms for a frame delay.\r\n    // For baud rates below 19200 the timeing is more critical and has to be calculated.\r\n    // E.g. 9600 baud in a 10 bit packet is 960 characters per second\r\n    // In milliseconds this will be 960characters per 1000ms. So for 1 character\r\n    // 1000ms/960characters is 1.04167ms per character and finaly modbus states an\r\n    // intercharacter must be 1.5T or 1.5 times longer than a normal character and thus\r\n    // 1.5T = 1.04167ms * 1.5 = 1.5625ms. A frame delay is 3.5T.\r\n    // Added experimental low latency delays. This makes the implementation\r\n    // non-standard but practically it works with all major modbus master implementations.\r\n\r\n    if (baud == 1000000 && _lowLatency) {\r\n        T1_5 = 1;\r\n        T3_5 = 10;\r\n    } else if (baud >= 115200 && _lowLatency) {\r\n        T1_5 = 75;\r\n        T3_5 = 175;\r\n    } else if (baud > 19200) {\r\n        T1_5 = 750;\r\n        T3_5 = 1750;\r\n    } else {\r\n        T1_5 = 15000000/baud; // 1T * 1.5 = T1.5\r\n        T3_5 = 35000000/baud; // 1T * 3.5 = T3.5\r\n    }\r\n\r\n    holdingRegsSize = _holdingRegsSize;\r\n    errorCount = 0; // initialize errorCount\r\n}\r\n\r\nunsigned int calculateCRC(byte bufferSize)\r\n{\r\n    unsigned int temp, temp2, flag;\r\n    temp = 0xFFFF;\r\n    for (unsigned char i = 0; i < bufferSize; i++) {\r\n        temp = temp ^ frame[i];\r\n        for (unsigned char j = 1; j <= 8; j++) {\r\n            flag = temp & 0x0001;\r\n            temp >>= 1;\r\n            if (flag)\r\n                temp ^= 0xA001;\r\n        }\r\n    }\r\n    // Reverse byte order.\r\n    temp2 = temp >> 8;\r\n    temp = (temp << 8) | temp2;\r\n    temp &= 0xFFFF;\r\n    return temp; // the returned value is already swopped - crcLo byte is first & crcHi byte is last\r\n}\r\n\r\nvoid sendPacket(unsigned char bufferSize)\r\n{\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, HIGH);\r\n\r\n    for (unsigned char i = 0; i < bufferSize; i++)\r\n        Serial.write(frame[i]);\r\n\r\n    Serial.flush();\r\n\r\n    // allow a frame delay to indicate end of transmission\r\n    delayMicroseconds(T3_5);\r\n\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, LOW);\r\n}\r\n"
  },
  {
    "path": "SimpleModbusSlave/SimpleModbusSlave.h",
    "content": "#ifndef SIMPLE_MODBUS_SLAVE_H\r\n#define SIMPLE_MODBUS_SLAVE_H\r\n\r\n/*\r\n  SimpleModbusSlave allows you to communicate\r\n  to any slave using the Modbus RTU protocol.\r\n  \r\n  The crc calculation is based on the work published\r\n  by jpmzometa at\r\n  http://sites.google.com/site/jpmzometa/arduino-mbrt\r\n  \r\n  By Juan Bester : bester.juan@gmail.com\r\n  \r\n  The functions implemented are functions 3 and 16.\r\n  read holding registers and preset multiple registers\r\n  of the Modbus RTU Protocol, to be used over the Arduino serial connection.\r\n  \r\n  This implementation DOES NOT fully comply with the Modbus specifications.\r\n  \r\n  Specifically the frame time out have not been implemented according\r\n  to Modbus standards. The code does however combine the check for\r\n  inter character time out and frame time out by incorporating a maximum\r\n  time out allowable when reading from the message stream.\r\n  \r\n  These library of functions are designed to enable a program send and\r\n  receive data from a device that communicates using the Modbus protocol.\r\n  \r\n  SimpleModbusSlave implements an unsigned int return value on a call to modbus_update().\r\n  This value is the total error count since the slave started. It's useful for fault finding.\r\n  \r\n  This code is for a Modbus slave implementing functions 3 and 16\r\n  function 3: Reads the binary contents of holding registers (4X references)\r\n  function 16: Presets values into a sequence of holding registers (4X references)\r\n  \r\n  All the functions share the same register array.\r\n  \r\n  Exception responses:\r\n  1 ILLEGAL FUNCTION\r\n  2 ILLEGAL DATA ADDRESS\r\n  3 ILLEGAL DATA VALUE\r\n  \r\n  Note:\r\n  The Arduino serial ring buffer is 128 bytes or 64 registers.\r\n  Most of the time you will connect the arduino to a master via serial\r\n  using a MAX485 or similar.\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 122 bytes or 61 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  118 bytes or 59 registers.\r\n  \r\n  Using the FTDI converter ic the maximum bytes you can send is limited\r\n  to its internal buffer which is 60 bytes or 30 unsigned int registers.\r\n  \r\n  Thus:\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 54 bytes or 27 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  50 bytes or 25 registers.\r\n  \r\n  Since it is assumed that you will mostly use the Arduino to connect to a\r\n  master without using a USB to Serial converter the internal buffer is set\r\n  the same as the Arduino Serial ring buffer which is 128 bytes.\r\n  \r\n  The functions included here have been derived from the\r\n  Modbus Specifications and Implementation Guides\r\n  \r\n  http://www.modbus.org/docs/Modbus_over_serial_line_V1_02.pdf\r\n  http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf\r\n  http://www.modbus.org/docs/PI_MBUS_300.pdf\r\n*/\r\n\r\n#include \"Arduino.h\"\r\n\r\n// function definitions\r\nvoid modbus_configure(long baud, byte _slaveID, byte _TxEnablePin, unsigned int _holdingRegsSize, unsigned char _lowLatency);\r\nunsigned int modbus_update(unsigned int *holdingRegs);\r\n\r\n\r\n#endif\r\n"
  },
  {
    "path": "SimpleModbusSlave/examples/SimpleModbusSlaveExample/SimpleModbusSlaveExample.ino",
    "content": "#include <SimpleModbusSlave.h>\n\n#define  ledPin  13 // onboard led \n#define  buttonPin  7 // push button\n\n/* This example code has 9 holding registers. 6 analogue inputs, 1 button, 1 digital output\n   and 1 register to indicate errors encountered since started.\n   Function 5 (write single coil) is not implemented so I'm using a whole register\n   and function 16 to set the onboard Led on the Atmega328P.\n\n   The modbus_update() method updates the holdingRegs register array and checks communication.\n\n   Note:\n   The Arduino serial ring buffer is 128 bytes or 64 registers.\n   Most of the time you will connect the arduino to a master via serial\n   using a MAX485 or similar.\n\n   In a function 3 request the master will attempt to read from your\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\n   and two BYTES CRC the master can only request 122 bytes or 61 registers.\n\n   In a function 16 request the master will attempt to write to your\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\n   118 bytes or 59 registers.\n\n   Using the FTDI USB to Serial converter the maximum bytes you can send is limited\n   to its internal buffer which is 60 bytes or 30 unsigned int registers.\n\n   Thus:\n\n   In a function 3 request the master will attempt to read from your\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\n   and two BYTES CRC the master can only request 54 bytes or 27 registers.\n\n   In a function 16 request the master will attempt to write to your\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\n   50 bytes or 25 registers.\n\n   Since it is assumed that you will mostly use the Arduino to connect to a\n   master without using a USB to Serial converter the internal buffer is set\n   the same as the Arduino Serial ring buffer which is 128 bytes.\n*/\n\n\n// Using the enum instruction allows for an easy method for adding and\n// removing registers. Doing it this way saves you #defining the size\n// of your slaves register array each time you want to add more registers\n// and at a glimpse informs you of your slaves register layout.\n\n//////////////// registers of your slave ///////////////////\nenum {\n    // just add or remove registers and you're good to go...\n    // The first register starts at address 0\n    ADC0,\n    ADC1,\n    ADC2,\n    ADC3,\n    ADC4,\n    ADC5,\n    LED_STATE,\n    BUTTON_STATE,\n    TOTAL_ERRORS,\n    // leave this one\n    TOTAL_REGS_SIZE\n    // total number of registers for function 3 and 16 share the same register array\n};\n\nunsigned int holdingRegs[TOTAL_REGS_SIZE]; // function 3 and 16 register array\n////////////////////////////////////////////////////////////\n\nvoid setup()\n{\n    /* parameters(long baudrate,\n                  unsigned char ID,\n                  unsigned char transmit enable pin,\n                  unsigned int holding registers size,\n                  unsigned char low latency)\n\n       The transmit enable pin is used in half duplex communication to activate a MAX485 or similar\n       to deactivate this mode use any value < 2 because 0 & 1 is reserved for Rx & Tx.\n       Low latency delays makes the implementation non-standard\n       but practically it works with all major modbus master implementations.\n    */\n\n    modbus_configure(115200, 2, 2, TOTAL_REGS_SIZE, 0);\n    pinMode(ledPin, OUTPUT);\n    pinMode(buttonPin, INPUT);\n}\n\nvoid loop()\n{\n    // modbus_update() is the only method used in loop(). It returns the total error\n    // count since the slave started. You don't have to use it but it's useful\n    // for fault finding by the modbus master.\n    holdingRegs[TOTAL_ERRORS] = modbus_update(holdingRegs);\n    for (byte i = 0; i < 6; i++) {\n        holdingRegs[i] = analogRead(i);\n        delayMicroseconds(50);\n    }\n\n    byte buttonState = digitalRead(buttonPin); // read button states\n\n    // assign the buttonState value to the holding register\n    holdingRegs[BUTTON_STATE] = buttonState;\n\n    // read the LED_STATE register value and set the onboard LED high or low with function 16\n    byte ledState = holdingRegs[LED_STATE];\n\n    if (ledState) // set led\n        digitalWrite(ledPin, HIGH);\n    if (ledState == 0) { // reset led\n        digitalWrite(ledPin, LOW);\n    }\n}\n\n"
  },
  {
    "path": "SimpleModbusSlave/keywords.txt",
    "content": "modbus_configure KEYWORD2\r\nmodbus_update\t KEYWORD2\r\n"
  },
  {
    "path": "SimpleModbusSlaveSoftwareSerial/SimpleModbusSlaveSoftwareSerial.cpp",
    "content": "#include \"SimpleModbusSlaveSoftwareSerial.h\"\r\n\r\n#define BUFFER_SIZE 128\r\n\r\n// frame[] is used to recieve and transmit packages.\r\n// The maximum serial ring buffer size is 128\r\nunsigned char frame[BUFFER_SIZE];\r\nunsigned int holdingRegsSize; // size of the register array\r\nunsigned char broadcastFlag;\r\nunsigned char slaveID;\r\nunsigned char function;\r\nunsigned char TxEnablePin;\r\nunsigned int errorCount;\r\nunsigned int T1_5; // inter character time out\r\nunsigned int T3_5; // frame delay\r\nSoftwareSerial* _port;\r\n\r\n// function definitions\r\nvoid exceptionResponse(unsigned char exception);\r\nunsigned int calculateCRC(unsigned char bufferSize);\r\nvoid sendPacket(unsigned char bufferSize);\r\n\r\nunsigned int modbus_update(unsigned int *holdingRegs)\r\n{\r\n    unsigned char buffer = 0;\r\n    unsigned char overflow = 0;\r\n\r\n    while ((*_port).available()) {\r\n        // The maximum number of bytes is limited to the serial buffer size of 128 bytes\r\n        // If more bytes is received than the BUFFER_SIZE the overflow flag will be set and the\r\n        // serial buffer will be red untill all the data is cleared from the receive buffer.\r\n        if (overflow)\r\n            (*_port).read();\r\n        else {\r\n            if (buffer == BUFFER_SIZE)\r\n                overflow = 1;\r\n            frame[buffer] = (*_port).read();\r\n            buffer++;\r\n        }\r\n        delayMicroseconds(T1_5); // inter character time out\r\n    }\r\n\r\n    // If an overflow occurred increment the errorCount\r\n    // variable and return to the main sketch without\r\n    // responding to the request i.e. force a timeout\r\n    if (overflow)\r\n        return errorCount++;\r\n\r\n    // The minimum request packet is 8 bytes for function 3 & 16\r\n    if (buffer > 6) {\r\n        unsigned char id = frame[0];\r\n\r\n        broadcastFlag = 0;\r\n\r\n        if (id == 0)\r\n            broadcastFlag = 1;\r\n\r\n        if (id == slaveID || broadcastFlag) { // if the recieved ID matches the slaveID or broadcasting id (0), continue\r\n            unsigned int crc = ((frame[buffer - 2] << 8) | frame[buffer - 1]); // combine the crc Low & High bytes\r\n            if (calculateCRC(buffer - 2) == crc) { // if the calculated crc matches the recieved crc continue\r\n                function = frame[1];\r\n                unsigned int startingAddress = ((frame[2] << 8) | frame[3]); // combine the starting address bytes\r\n                unsigned int no_of_registers = ((frame[4] << 8) | frame[5]); // combine the number of register bytes\r\n                unsigned int maxData = startingAddress + no_of_registers;\r\n                unsigned char index;\r\n                unsigned char address;\r\n                unsigned int crc16;\r\n\r\n                // broadcasting is not supported for function 3\r\n                if (!broadcastFlag && (function == 3)) {\r\n                    if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                        if (maxData <= holdingRegsSize) { // check exception 3 ILLEGAL DATA VALUE\r\n                            unsigned char noOfBytes = no_of_registers * 2;\r\n                            unsigned char responseFrameSize = 5 + noOfBytes; // ID, function, noOfBytes, (dataLo + dataHi) * number of registers, crcLo, crcHi\r\n                            frame[0] = slaveID;\r\n                            frame[1] = function;\r\n                            frame[2] = noOfBytes;\r\n                            address = 3; // PDU starts at the 4th byte\r\n                            unsigned int temp;\r\n\r\n                            for (index = startingAddress; index < maxData; index++) {\r\n                                temp = holdingRegs[index];\r\n                                frame[address] = temp >> 8; // split the register into 2 bytes\r\n                                address++;\r\n                                frame[address] = temp & 0xFF;\r\n                                address++;\r\n                            }\r\n\r\n                            crc16 = calculateCRC(responseFrameSize - 2);\r\n                            frame[responseFrameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n                            frame[responseFrameSize - 1] = crc16 & 0xFF;\r\n                            sendPacket(responseFrameSize);\r\n                        } else\r\n                            exceptionResponse(3); // exception 3 ILLEGAL DATA VALUE\r\n                    } else\r\n                        exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                } else if (function == 6) {\r\n                    if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                        unsigned int startingAddress = ((frame[2] << 8) | frame[3]);\r\n                        unsigned int regStatus = ((frame[4] << 8) | frame[5]);\r\n                        unsigned char responseFrameSize = 8;\r\n\r\n                        holdingRegs[startingAddress] = regStatus;\r\n\r\n                        crc16 = calculateCRC(responseFrameSize - 2);\r\n                        frame[responseFrameSize - 2] = crc16 >> 8; // split crc into 2 bytes\r\n                        frame[responseFrameSize - 1] = crc16 & 0xFF;\r\n                        sendPacket(responseFrameSize);\r\n                    } else\r\n                        exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                } else if (function == 16) {\r\n                    // check if the recieved number of bytes matches the calculated bytes minus the request bytes\r\n                    // id + function + (2 * address bytes) + (2 * no of register bytes) + byte count + (2 * CRC bytes) = 9 bytes\r\n                    if (frame[6] == (buffer - 9)) {\r\n                        if (startingAddress < holdingRegsSize) { // check exception 2 ILLEGAL DATA ADDRESS\r\n                            if (maxData <= holdingRegsSize) { // check exception 3 ILLEGAL DATA VALUE\r\n                                address = 7; // start at the 8th byte in the frame\r\n\r\n                                for (index = startingAddress; index < maxData; index++) {\r\n                                    holdingRegs[index] = ((frame[address] << 8) | frame[address + 1]);\r\n                                    address += 2;\r\n                                }\r\n\r\n                                // only the first 6 bytes are used for CRC calculation\r\n                                crc16 = calculateCRC(6);\r\n                                frame[6] = crc16 >> 8; // split crc into 2 bytes\r\n                                frame[7] = crc16 & 0xFF;\r\n\r\n                                // a function 16 response is an echo of the first 6 bytes from the request + 2 crc bytes\r\n                                if (!broadcastFlag) // don't respond if it's a broadcast message\r\n                                    sendPacket(8);\r\n                            } else\r\n                                exceptionResponse(3); // exception 3 ILLEGAL DATA VALUE\r\n                        } else\r\n                            exceptionResponse(2); // exception 2 ILLEGAL DATA ADDRESS\r\n                    } else\r\n                        errorCount++; // corrupted packet\r\n                } else\r\n                    exceptionResponse(1); // exception 1 ILLEGAL FUNCTION\r\n            } else // checksum failed\r\n                errorCount++;\r\n        } // incorrect id\r\n    } else if (buffer > 0 && buffer < 8)\r\n        errorCount++; // corrupted packet\r\n\r\n    return errorCount;\r\n}\r\n\r\nvoid exceptionResponse(unsigned char exception)\r\n{\r\n    errorCount++; // each call to exceptionResponse() will increment the errorCount\r\n    if (!broadcastFlag) { // don't respond if its a broadcast message\r\n        frame[0] = slaveID;\r\n        frame[1] = (function | 0x80); // set the MSB bit high, informs the master of an exception\r\n        frame[2] = exception;\r\n        unsigned int crc16 = calculateCRC(3); // ID, function + 0x80, exception code == 3 bytes\r\n        frame[3] = crc16 >> 8;\r\n        frame[4] = crc16 & 0xFF;\r\n        sendPacket(5); // exception response is always 5 bytes ID, function + 0x80, exception code, 2 bytes crc\r\n    }\r\n}\r\n\r\nvoid modbus_configure(SoftwareSerial* comPort, long baud, unsigned char _slaveID, unsigned char _TxEnablePin, unsigned int _holdingRegsSize)\r\n{\r\n    _port = comPort;\r\n    slaveID = _slaveID;\r\n    (*_port).begin(baud);\r\n\r\n    if (_TxEnablePin > 1) {\r\n        // pin 0 & pin 1 are reserved for RX/TX. To disable set txenpin < 2\r\n        TxEnablePin = _TxEnablePin;\r\n        pinMode(TxEnablePin, OUTPUT);\r\n        digitalWrite(TxEnablePin, LOW);\r\n    }\r\n\r\n    // Modbus states that a baud rate higher than 19200 must use a fixed 750 us\r\n    // for inter character time out and 1.75 ms for a frame delay.\r\n    // For baud rates below 19200 the timeing is more critical and has to be calculated.\r\n    // E.g. 9600 baud in a 10 bit packet is 960 characters per second\r\n    // In milliseconds this will be 960characters per 1000ms. So for 1 character\r\n    // 1000ms/960characters is 1.04167ms per character and finaly modbus states an\r\n    // intercharacter must be 1.5T or 1.5 times longer than a normal character and thus\r\n    // 1.5T = 1.04167ms * 1.5 = 1.5625ms. A frame delay is 3.5T.\r\n\r\n    if (baud > 19200) {\r\n        T1_5 = 150;\r\n        T3_5 = 350;\r\n    } else {\r\n        T1_5 = 15000000/baud; // 1T * 1.5 = T1.5\r\n        T3_5 = 35000000/baud; // 1T * 3.5 = T3.5\r\n    }\r\n\r\n    holdingRegsSize = _holdingRegsSize;\r\n    errorCount = 0; // initialize errorCount\r\n}\r\n\r\nunsigned int calculateCRC(byte bufferSize)\r\n{\r\n    unsigned int temp, temp2, flag;\r\n    temp = 0xFFFF;\r\n    for (unsigned char i = 0; i < bufferSize; i++) {\r\n        temp = temp ^ frame[i];\r\n        for (unsigned char j = 1; j <= 8; j++) {\r\n            flag = temp & 0x0001;\r\n            temp >>= 1;\r\n            if (flag)\r\n                temp ^= 0xA001;\r\n        }\r\n    }\r\n    // Reverse byte order.\r\n    temp2 = temp >> 8;\r\n    temp = (temp << 8) | temp2;\r\n    temp &= 0xFFFF;\r\n    return temp; // the returned value is already swopped - crcLo byte is first & crcHi byte is last\r\n}\r\n\r\nvoid sendPacket(unsigned char bufferSize)\r\n{\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, HIGH);\r\n\r\n    for (unsigned char i = 0; i < bufferSize; i++)\r\n        (*_port).write(frame[i]);\r\n\r\n    (*_port).flush();\r\n\r\n    // allow a frame delay to indicate end of transmission\r\n    delayMicroseconds(T3_5);\r\n\r\n    if (TxEnablePin > 1)\r\n        digitalWrite(TxEnablePin, LOW);\r\n}\r\n"
  },
  {
    "path": "SimpleModbusSlaveSoftwareSerial/SimpleModbusSlaveSoftwareSerial.h",
    "content": "#ifndef SIMPLE_MODBUS_SLAVE_H\r\n#define SIMPLE_MODBUS_SLAVE_H\r\n\r\n/*\r\n  SimpleModbusSlave allows you to communicate\r\n  to any slave using the Modbus RTU protocol.\r\n  \r\n  The crc calculation is based on the work published\r\n  by jpmzometa at\r\n  http://sites.google.com/site/jpmzometa/arduino-mbrt\r\n  \r\n  By Juan Bester : bester.juan@gmail.com\r\n  \r\n  The functions implemented are functions 3 and 16.\r\n  read holding registers and preset multiple registers\r\n  of the Modbus RTU Protocol, to be used over the Arduino serial connection.\r\n  \r\n  This implementation DOES NOT fully comply with the Modbus specifications.\r\n  \r\n  Specifically the frame time out have not been implemented according\r\n  to Modbus standards. The code does however combine the check for\r\n  inter character time out and frame time out by incorporating a maximum\r\n  time out allowable when reading from the message stream.\r\n  \r\n  These library of functions are designed to enable a program send and\r\n  receive data from a device that communicates using the Modbus protocol.\r\n  \r\n  SimpleModbusSlave implements an unsigned int return value on a call to modbus_update().\r\n  This value is the total error count since the slave started. It's useful for fault finding.\r\n  \r\n  This code is for a Modbus slave implementing functions 3 and 16\r\n  function 3: Reads the binary contents of holding registers (4X references)\r\n  function 16: Presets values into a sequence of holding registers (4X references)\r\n  \r\n  All the functions share the same register array.\r\n  \r\n  Exception responses:\r\n  1 ILLEGAL FUNCTION\r\n  2 ILLEGAL DATA ADDRESS\r\n  3 ILLEGAL DATA VALUE\r\n  \r\n  Note:\r\n  The Arduino serial ring buffer is 128 bytes or 64 registers.\r\n  Most of the time you will connect the arduino to a master via serial\r\n  using a MAX485 or similar.\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 122 bytes or 61 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  118 bytes or 59 registers.\r\n  \r\n  Using the FTDI converter ic the maximum bytes you can send is limited\r\n  to its internal buffer which is 60 bytes or 30 unsigned int registers.\r\n  \r\n  Thus:\r\n  \r\n  In a function 3 request the master will attempt to read from your\r\n  slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\r\n  and two BYTES CRC the master can only request 54 bytes or 27 registers.\r\n  \r\n  In a function 16 request the master will attempt to write to your\r\n  slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\r\n  NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\r\n  50 bytes or 25 registers.\r\n  \r\n  Since it is assumed that you will mostly use the Arduino to connect to a\r\n  master without using a USB to Serial converter the internal buffer is set\r\n  the same as the Arduino Serial ring buffer which is 128 bytes.\r\n  \r\n  The functions included here have been derived from the\r\n  Modbus Specifications and Implementation Guides\r\n  \r\n  http://www.modbus.org/docs/Modbus_over_serial_line_V1_02.pdf\r\n  http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf\r\n  http://www.modbus.org/docs/PI_MBUS_300.pdf\r\n*/\r\n\r\n#include \"Arduino.h\"\r\n#include \"SoftwareSerial.h\"\r\n\r\n// function definitions\r\nvoid modbus_configure(SoftwareSerial* comPort, long baud, unsigned char _slaveID, unsigned char _TxEnablePin, unsigned int _holdingRegsSize);\r\nunsigned int modbus_update(unsigned int *holdingRegs);\r\n\r\n#endif\r\n"
  },
  {
    "path": "SimpleModbusSlaveSoftwareSerial/examples/SimpleModbusTinyExample/SimpleModbusTinyExample.ino",
    "content": "#include <SoftwareSerial.h>\n#include <SimpleModbusSlaveSoftwareSerial.h>\n\n#define  buttonPin0  2 // push button\n#define  buttonPin1  3 // push button\n\n/* This example code has 2 holding registers. 2 buttons,\n   and 1 register to indicate errors encountered since started.\n\n   The modbus_update() method updates the holdingRegs register array\n   and checks communication.\n\n   Note:\n   The Arduino serial ring buffer is 128 bytes or 64 registers.\n   Most of the time you will connect the arduino to a master via serial\n   using a MAX485 or similar.\n\n   In a function 3 request the master will attempt to read from your\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\n   and two BYTES CRC the master can only request 122 bytes or 61 registers.\n\n   In a function 16 request the master will attempt to write to your\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\n   118 bytes or 59 registers.\n\n   Using the FTDI USB to Serial converter the maximum bytes you can send is limited\n   to its internal buffer which is 60 bytes or 30 unsigned int registers.\n\n   Thus:\n\n   In a function 3 request the master will attempt to read from your\n   slave and since 5 bytes is already used for ID, FUNCTION, NO OF BYTES\n   and two BYTES CRC the master can only request 54 bytes or 27 registers.\n\n   In a function 16 request the master will attempt to write to your\n   slave and since a 9 bytes is already used for ID, FUNCTION, ADDRESS,\n   NO OF REGISTERS, NO OF BYTES and two BYTES CRC the master can only write\n   50 bytes or 25 registers.\n\n   Since it is assumed that you will mostly use the Arduino to connect to a\n   master without using a USB to Serial converter the internal buffer is set\n   the same as the Arduino Serial ring buffer which is 128 bytes.\n*/\n\n\n// Using the enum instruction allows for an easy method for adding and\n// removing registers. Doing it this way saves you #defining the size\n// of your slaves register array each time you want to add more registers\n// and at a glimpse informs you of your slaves register layout.\n\n//////////////// registers of your slave ///////////////////\nenum {\n    // just add or remove registers and your good to go...\n    // The first register starts at address 0\n    BUTTON0,\n    BUTTON1,\n    TOTAL_ERRORS,\n    // leave this one\n    TOTAL_REGS_SIZE\n    // total number of registers for function 3 and 16 share the same register array\n};\n\nunsigned int holdingRegs[TOTAL_REGS_SIZE]; // function 3 and 16 register array\n////////////////////////////////////////////////////////////\n\n#define RX            0       // Arduino defined pin (PB0, package pin #5)\n#define TX            1       // Arduino defined pin (PB1, package pin #6)\n#define RS485_EN      2       // pin to set transmission mode on RS485 chip (PB2, package pin #7)\n#define BAUD_RATE     115200  // baud rate for serial communication\n#define deviceID      3       // this device address\n\nSoftwareSerial mySerial(RX, TX);\n\nvoid setup()\n{\n    /* parameters(\n                  SoftwareSerial* comPort\n                  long baudrate,\n                  unsigned char ID,\n                  unsigned char transmit enable pin,\n                  unsigned int holding registers size)\n\n       The transmit enable pin is used in half duplex communication to activate a MAX485 or similar\n       to deactivate this mode use any value < 2 because 0 & 1 is reserved for Rx & Tx\n    */\n\n    modbus_configure(&mySerial, BAUD_RATE, deviceID, RS485_EN, TOTAL_REGS_SIZE);\n    pinMode(buttonPin0, INPUT);\n    pinMode(buttonPin1, INPUT);\n}\n\nvoid loop()\n{\n    // modbus_update() is the only method used in loop(). It returns the total error\n    // count since the slave started. You don't have to use it but it's useful\n    // for fault finding by the modbus master.\n    holdingRegs[TOTAL_ERRORS] = modbus_update(holdingRegs);\n    holdingRegs[BUTTON0] = analogRead(buttonPin0);\n    delayMicroseconds(50);\n    holdingRegs[BUTTON1] = analogRead(buttonPin1);\n    delayMicroseconds(50);\n}\n\n"
  },
  {
    "path": "SimpleModbusSlaveSoftwareSerial/keywords.txt",
    "content": "modbus_configure KEYWORD2\r\nmodbus_update\t KEYWORD2\r\n"
  },
  {
    "path": "gpl-3.0.txt",
    "content": "                    GNU GENERAL PUBLIC LICENSE\n                       Version 3, 29 June 2007\n\n Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>\n Everyone is permitted to copy and distribute verbatim copies\n of this license document, but changing it is not allowed.\n\n                            Preamble\n\n  The GNU General Public License is a free, copyleft license for\nsoftware and other kinds of works.\n\n  The licenses for most software and other practical works are designed\nto take away your freedom to share and change the works.  By contrast,\nthe GNU General Public License is intended to guarantee your freedom to\nshare and change all versions of a program--to make sure it remains free\nsoftware for all its users.  We, the Free Software Foundation, use the\nGNU General Public License for most of our software; it applies also to\nany other work released this way by its authors.  You can apply it to\nyour programs, too.\n\n  When we speak of free software, we are referring to freedom, not\nprice.  Our General Public Licenses are designed to make sure that you\nhave the freedom to distribute copies of free software (and charge for\nthem if you wish), that you receive source code or can get it if you\nwant it, that you can change the software or use pieces of it in new\nfree programs, and that you know you can do these things.\n\n  To protect your rights, we need to prevent others from denying you\nthese rights or asking you to surrender the rights.  Therefore, you have\ncertain responsibilities if you distribute copies of the software, or if\nyou modify it: responsibilities to respect the freedom of others.\n\n  For example, if you distribute copies of such a program, whether\ngratis or for a fee, you must pass on to the recipients the same\nfreedoms that you received.  You must make sure that they, too, receive\nor can get the source code.  And you must show them these terms so they\nknow their rights.\n\n  Developers that use the GNU GPL protect your rights with two steps:\n(1) assert copyright on the software, and (2) offer you this License\ngiving you legal permission to copy, distribute and/or modify it.\n\n  For the developers' and authors' protection, the GPL clearly explains\nthat there is no warranty for this free software.  For both users' and\nauthors' sake, the GPL requires that modified versions be marked as\nchanged, so that their problems will not be attributed erroneously to\nauthors of previous versions.\n\n  Some devices are designed to deny users access to install or run\nmodified versions of the software inside them, although the manufacturer\ncan do so.  This is fundamentally incompatible with the aim of\nprotecting users' freedom to change the software.  The systematic\npattern of such abuse occurs in the area of products for individuals to\nuse, which is precisely where it is most unacceptable.  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Conveying Verbatim Copies.\n\n  You may convey verbatim copies of the Program's source code as you\nreceive it, in any medium, provided that you conspicuously and\nappropriately publish on each copy an appropriate copyright notice;\nkeep intact all notices stating that this License and any\nnon-permissive terms added in accord with section 7 apply to the code;\nkeep intact all notices of the absence of any warranty; and give all\nrecipients a copy of this License along with the Program.\n\n  You may charge any price or no price for each copy that you convey,\nand you may offer support or warranty protection for a fee.\n\n  5. Conveying Modified Source Versions.\n\n  You may convey a work based on the Program, or the modifications to\nproduce it from the Program, in the form of source code under the\nterms of section 4, provided that you also meet all of these conditions:\n\n    a) The work must carry prominent notices stating that you modified\n    it, and giving a relevant date.\n\n    b) The work must carry prominent notices stating that it is\n    released under this License and any conditions added under section\n    7.  This requirement modifies the requirement in section 4 to\n    \"keep intact all notices\".\n\n    c) You must license the entire work, as a whole, under this\n    License to anyone who comes into possession of a copy.  This\n    License will therefore apply, along with any applicable section 7\n    additional terms, to the whole of the work, and all its parts,\n    regardless of how they are packaged.  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Conveying Non-Source Forms.\n\n  You may convey a covered work in object code form under the terms\nof sections 4 and 5, provided that you also convey the\nmachine-readable Corresponding Source under the terms of this License,\nin one of these ways:\n\n    a) Convey the object code in, or embodied in, a physical product\n    (including a physical distribution medium), accompanied by the\n    Corresponding Source fixed on a durable physical medium\n    customarily used for software interchange.\n\n    b) Convey the object code in, or embodied in, a physical product\n    (including a physical distribution medium), accompanied by a\n    written offer, valid for at least three years and valid for as\n    long as you offer spare parts or customer support for that product\n    model, to give anyone who possesses the object code either (1) a\n    copy of the Corresponding Source for all the software in the\n    product that is covered by this License, on a durable physical\n    medium customarily used for software interchange, for a price no\n    more than your reasonable cost of physically performing this\n    conveying of source, or (2) access to copy the\n    Corresponding Source from a network server at no charge.\n\n    c) Convey individual copies of the object code with a copy of the\n    written offer to provide the Corresponding Source.  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Regardless of what server hosts the\n    Corresponding Source, you remain obligated to ensure that it is\n    available for as long as needed to satisfy these requirements.\n\n    e) Convey the object code using peer-to-peer transmission, provided\n    you inform other peers where the object code and Corresponding\n    Source of the work are being offered to the general public at no\n    charge under subsection 6d.\n\n  A separable portion of the object code, whose source code is excluded\nfrom the Corresponding Source as a System Library, need not be\nincluded in conveying the object code work.\n\n  A \"User Product\" is either (1) a \"consumer product\", which means any\ntangible personal property which is normally used for personal, family,\nor household purposes, or (2) anything designed or sold for incorporation\ninto a dwelling.  In determining whether a product is a consumer product,\ndoubtful cases shall be resolved in favor of coverage.  For a particular\nproduct received by a particular user, \"normally used\" refers to a\ntypical or common use of that class of product, regardless of the status\nof the particular user or of the way in which the particular user\nactually uses, or expects or is expected to use, the product.  A product\nis a consumer product regardless of whether the product has substantial\ncommercial, industrial or non-consumer uses, unless such uses represent\nthe only significant mode of use of the product.\n\n  \"Installation Information\" for a User Product means any methods,\nprocedures, authorization keys, or other information required to install\nand execute modified versions of a covered work in that User Product from\na modified version of its Corresponding Source.  The information must\nsuffice to ensure that the continued functioning of the modified object\ncode is in no case prevented or interfered with solely because\nmodification has been made.\n\n  If you convey an object code work under this section in, or with, or\nspecifically for use in, a User Product, and the conveying occurs as\npart of a transaction in which the right of possession and use of the\nUser Product is transferred to the recipient in perpetuity or for a\nfixed term (regardless of how the transaction is characterized), the\nCorresponding Source conveyed under this section must be accompanied\nby the Installation Information.  But this requirement does not apply\nif neither you nor any third party retains the ability to install\nmodified object code on the User Product (for example, the work has\nbeen installed in ROM).\n\n  The requirement to provide Installation Information does not include a\nrequirement to continue to provide support service, warranty, or updates\nfor a work that has been modified or installed by the recipient, or for\nthe User Product in which it has been modified or installed.  Access to a\nnetwork may be denied when the modification itself materially and\nadversely affects the operation of the network or violates the rules and\nprotocols for communication across the network.\n\n  Corresponding Source conveyed, and Installation Information provided,\nin accord with this section must be in a format that is publicly\ndocumented (and with an implementation available to the public in\nsource code form), and must require no special password or key for\nunpacking, reading or copying.\n\n  7. Additional Terms.\n\n  \"Additional permissions\" are terms that supplement the terms of this\nLicense by making exceptions from one or more of its conditions.\nAdditional permissions that are applicable to the entire Program shall\nbe treated as though they were included in this License, to the extent\nthat they are valid under applicable law.  If additional permissions\napply only to part of the Program, that part may be used separately\nunder those permissions, but the entire Program remains governed by\nthis License without regard to the additional permissions.\n\n  When you convey a copy of a covered work, you may at your option\nremove any additional permissions from that copy, or from any part of\nit.  (Additional permissions may be written to require their own\nremoval in certain cases when you modify the work.)  You may place\nadditional permissions on material, added by you to a covered work,\nfor which you have or can give appropriate copyright permission.\n\n  Notwithstanding any other provision of this License, for material you\nadd to a covered work, you may (if authorized by the copyright holders of\nthat material) supplement the terms of this License with terms:\n\n    a) Disclaiming warranty or limiting liability differently from the\n    terms of sections 15 and 16 of this License; or\n\n    b) Requiring preservation of specified reasonable legal notices or\n    author attributions in that material or in the Appropriate Legal\n    Notices displayed by works containing it; or\n\n    c) Prohibiting misrepresentation of the origin of that material, or\n    requiring that modified versions of such material be marked in\n    reasonable ways as different from the original version; or\n\n    d) Limiting the use for publicity purposes of names of licensors or\n    authors of the material; or\n\n    e) Declining to grant rights under trademark law for use of some\n    trade names, trademarks, or service marks; or\n\n    f) Requiring indemnification of licensors and authors of that\n    material by anyone who conveys the material (or modified versions of\n    it) with contractual assumptions of liability to the recipient, for\n    any liability that these contractual assumptions directly impose on\n    those licensors and authors.\n\n  All other non-permissive additional terms are considered \"further\nrestrictions\" within the meaning of section 10.  If the Program as you\nreceived it, or any part of it, contains a notice stating that it is\ngoverned by this License along with a term that is a further\nrestriction, you may remove that term.  If a license document contains\na further restriction but permits relicensing or conveying under this\nLicense, you may add to a covered work material governed by the terms\nof that license document, provided that the further restriction does\nnot survive such relicensing or conveying.\n\n  If you add terms to a covered work in accord with this section, you\nmust place, in the relevant source files, a statement of the\nadditional terms that apply to those files, or a notice indicating\nwhere to find the applicable terms.\n\n  Additional terms, permissive or non-permissive, may be stated in the\nform of a separately written license, or stated as exceptions;\nthe above requirements apply either way.\n\n  8. Termination.\n\n  You may not propagate or modify a covered work except as expressly\nprovided under this License.  Any attempt otherwise to propagate or\nmodify it is void, and will automatically terminate your rights under\nthis License (including any patent licenses granted under the third\nparagraph of section 11).\n\n  However, if you cease all violation of this License, then your\nlicense from a particular copyright holder is reinstated (a)\nprovisionally, unless and until the copyright holder explicitly and\nfinally terminates your license, and (b) permanently, if the copyright\nholder fails to notify you of the violation by some reasonable means\nprior to 60 days after the cessation.\n\n  Moreover, your license from a particular copyright holder is\nreinstated permanently if the copyright holder notifies you of the\nviolation by some reasonable means, this is the first time you have\nreceived notice of violation of this License (for any work) from that\ncopyright holder, and you cure the violation prior to 30 days after\nyour receipt of the notice.\n\n  Termination of your rights under this section does not terminate the\nlicenses of parties who have received copies or rights from you under\nthis License.  If your rights have been terminated and not permanently\nreinstated, you do not qualify to receive new licenses for the same\nmaterial under section 10.\n\n  9. Acceptance Not Required for Having Copies.\n\n  You are not required to accept this License in order to receive or\nrun a copy of the Program.  Ancillary propagation of a covered work\noccurring solely as a consequence of using peer-to-peer transmission\nto receive a copy likewise does not require acceptance.  However,\nnothing other than this License grants you permission to propagate or\nmodify any covered work.  These actions infringe copyright if you do\nnot accept this License.  Therefore, by modifying or propagating a\ncovered work, you indicate your acceptance of this License to do so.\n\n  10. Automatic Licensing of Downstream Recipients.\n\n  Each time you convey a covered work, the recipient automatically\nreceives a license from the original licensors, to run, modify and\npropagate that work, subject to this License.  You are not responsible\nfor enforcing compliance by third parties with this License.\n\n  An \"entity transaction\" is a transaction transferring control of an\norganization, or substantially all assets of one, or subdividing an\norganization, or merging organizations.  If propagation of a covered\nwork results from an entity transaction, each party to that\ntransaction who receives a copy of the work also receives whatever\nlicenses to the work the party's predecessor in interest had or could\ngive under the previous paragraph, plus a right to possession of the\nCorresponding Source of the work from the predecessor in interest, if\nthe predecessor has it or can get it with reasonable efforts.\n\n  You may not impose any further restrictions on the exercise of the\nrights granted or affirmed under this License.  For example, you may\nnot impose a license fee, royalty, or other charge for exercise of\nrights granted under this License, and you may not initiate litigation\n(including a cross-claim or counterclaim in a lawsuit) alleging that\nany patent claim is infringed by making, using, selling, offering for\nsale, or importing the Program or any portion of it.\n\n  11. Patents.\n\n  A \"contributor\" is a copyright holder who authorizes use under this\nLicense of the Program or a work on which the Program is based.  The\nwork thus licensed is called the contributor's \"contributor version\".\n\n  A contributor's \"essential patent claims\" are all patent claims\nowned or controlled by the contributor, whether already acquired or\nhereafter acquired, that would be infringed by some manner, permitted\nby this License, of making, using, or selling its contributor version,\nbut do not include claims that would be infringed only as a\nconsequence of further modification of the contributor version.  For\npurposes of this definition, \"control\" includes the right to grant\npatent sublicenses in a manner consistent with the requirements of\nthis License.\n\n  Each contributor grants you a non-exclusive, worldwide, royalty-free\npatent license under the contributor's essential patent claims, to\nmake, use, sell, offer for sale, import and otherwise run, modify and\npropagate the contents of its contributor version.\n\n  In the following three paragraphs, a \"patent license\" is any express\nagreement or commitment, however denominated, not to enforce a patent\n(such as an express permission to practice a patent or covenant not to\nsue for patent infringement).  To \"grant\" such a patent license to a\nparty means to make such an agreement or commitment not to enforce a\npatent against the party.\n\n  If you convey a covered work, knowingly relying on a patent license,\nand the Corresponding Source of the work is not available for anyone\nto copy, free of charge and under the terms of this License, through a\npublicly available network server or other readily accessible means,\nthen you must either (1) cause the Corresponding Source to be so\navailable, or (2) arrange to deprive yourself of the benefit of the\npatent license for this particular work, or (3) arrange, in a manner\nconsistent with the requirements of this License, to extend the patent\nlicense to downstream recipients.  \"Knowingly relying\" means you have\nactual knowledge that, but for the patent license, your conveying the\ncovered work in a country, or your recipient's use of the covered work\nin a country, would infringe one or more identifiable patents in that\ncountry that you have reason to believe are valid.\n\n  If, pursuant to or in connection with a single transaction or\narrangement, you convey, or propagate by procuring conveyance of, a\ncovered work, and grant a patent license to some of the parties\nreceiving the covered work authorizing them to use, propagate, modify\nor convey a specific copy of the covered work, then the patent license\nyou grant is automatically extended to all recipients of the covered\nwork and works based on it.\n\n  A patent license is \"discriminatory\" if it does not include within\nthe scope of its coverage, prohibits the exercise of, or is\nconditioned on the non-exercise of one or more of the rights that are\nspecifically granted under this License.  You may not convey a covered\nwork if you are a party to an arrangement with a third party that is\nin the business of distributing software, under which you make payment\nto the third party based on the extent of your activity of conveying\nthe work, and under which the third party grants, to any of the\nparties who would receive the covered work from you, a discriminatory\npatent license (a) in connection with copies of the covered work\nconveyed by you (or copies made from those copies), or (b) primarily\nfor and in connection with specific products or compilations that\ncontain the covered work, unless you entered into that arrangement,\nor that patent license was granted, prior to 28 March 2007.\n\n  Nothing in this License shall be construed as excluding or limiting\nany implied license or other defenses to infringement that may\notherwise be available to you under applicable patent law.\n\n  12. No Surrender of Others' Freedom.\n\n  If conditions are imposed on you (whether by court order, agreement or\notherwise) that contradict the conditions of this License, they do not\nexcuse you from the conditions of this License.  If you cannot convey a\ncovered work so as to satisfy simultaneously your obligations under this\nLicense and any other pertinent obligations, then as a consequence you may\nnot convey it at all.  For example, if you agree to terms that obligate you\nto collect a royalty for further conveying from those to whom you convey\nthe Program, the only way you could satisfy both those terms and this\nLicense would be to refrain entirely from conveying the Program.\n\n  13. Use with the GNU Affero General Public License.\n\n  Notwithstanding any other provision of this License, you have\npermission to link or combine any covered work with a work licensed\nunder version 3 of the GNU Affero General Public License into a single\ncombined work, and to convey the resulting work.  The terms of this\nLicense will continue to apply to the part which is the covered work,\nbut the special requirements of the GNU Affero General Public License,\nsection 13, concerning interaction through a network will apply to the\ncombination as such.\n\n  14. Revised Versions of this License.\n\n  The Free Software Foundation may publish revised and/or new versions of\nthe GNU General Public License from time to time.  Such new versions will\nbe similar in spirit to the present version, but may differ in detail to\naddress new problems or concerns.\n\n  Each version is given a distinguishing version number.  If the\nProgram specifies that a certain numbered version of the GNU General\nPublic License \"or any later version\" applies to it, you have the\noption of following the terms and conditions either of that numbered\nversion or of any later version published by the Free Software\nFoundation.  If the Program does not specify a version number of the\nGNU General Public License, you may choose any version ever published\nby the Free Software Foundation.\n\n  If the Program specifies that a proxy can decide which future\nversions of the GNU General Public License can be used, that proxy's\npublic statement of acceptance of a version permanently authorizes you\nto choose that version for the Program.\n\n  Later license versions may give you additional or different\npermissions.  However, no additional obligations are imposed on any\nauthor or copyright holder as a result of your choosing to follow a\nlater version.\n\n  15. Disclaimer of Warranty.\n\n  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY\nAPPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT\nHOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM \"AS IS\" WITHOUT WARRANTY\nOF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,\nTHE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR\nPURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM\nIS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF\nALL NECESSARY SERVICING, REPAIR OR CORRECTION.\n\n  16. Limitation of Liability.\n\n  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING\nWILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS\nTHE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY\nGENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE\nUSE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF\nDATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD\nPARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),\nEVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF\nSUCH DAMAGES.\n\n  17. Interpretation of Sections 15 and 16.\n\n  If the disclaimer of warranty and limitation of liability provided\nabove cannot be given local legal effect according to their terms,\nreviewing courts shall apply local law that most closely approximates\nan absolute waiver of all civil liability in connection with the\nProgram, unless a warranty or assumption of liability accompanies a\ncopy of the Program in return for a fee.\n\n                     END OF TERMS AND CONDITIONS\n\n            How to Apply These Terms to Your New Programs\n\n  If you develop a new program, and you want it to be of the greatest\npossible use to the public, the best way to achieve this is to make it\nfree software which everyone can redistribute and change under these terms.\n\n  To do so, attach the following notices to the program.  It is safest\nto attach them to the start of each source file to most effectively\nstate the exclusion of warranty; and each file should have at least\nthe \"copyright\" line and a pointer to where the full notice is found.\n\n    <one line to give the program's name and a brief idea of what it does.>\n    Copyright (C) <year>  <name of author>\n\n    This program is free software: you can redistribute it and/or modify\n    it under the terms of the GNU General Public License as published by\n    the Free Software Foundation, either version 3 of the License, or\n    (at your option) any later version.\n\n    This program is distributed in the hope that it will be useful,\n    but WITHOUT ANY WARRANTY; without even the implied warranty of\n    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n    GNU General Public License for more details.\n\n    You should have received a copy of the GNU General Public License\n    along with this program.  If not, see <http://www.gnu.org/licenses/>.\n\nAlso add information on how to contact you by electronic and paper mail.\n\n  If the program does terminal interaction, make it output a short\nnotice like this when it starts in an interactive mode:\n\n    <program>  Copyright (C) <year>  <name of author>\n    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.\n    This is free software, and you are welcome to redistribute it\n    under certain conditions; type `show c' for details.\n\nThe hypothetical commands `show w' and `show c' should show the appropriate\nparts of the General Public License.  Of course, your program's commands\nmight be different; for a GUI interface, you would use an \"about box\".\n\n  You should also get your employer (if you work as a programmer) or school,\nif any, to sign a \"copyright disclaimer\" for the program, if necessary.\nFor more information on this, and how to apply and follow the GNU GPL, see\n<http://www.gnu.org/licenses/>.\n\n  The GNU General Public License does not permit incorporating your program\ninto proprietary programs.  If your program is a subroutine library, you\nmay consider it more useful to permit linking proprietary applications with\nthe library.  If this is what you want to do, use the GNU Lesser General\nPublic License instead of this License.  But first, please read\n<http://www.gnu.org/philosophy/why-not-lgpl.html>.\n"
  }
]