/**

 *  EControls, Inc. has placed this source code in the public domain. You can use, modify, and

 *  distribute the source code and executable programs based on the source code. However, note

 *  the following:

 *

 *   DISCLAIMER OF WARRANTY

 *   This source code is provided "as is" and without warranties as to performance or merchantability.

 *   The author and/or distributors of this source code may have made statements about this source code; any

 *   such statements do not constitute warranties and shall not be relied on by the user in deciding whether

 *   to use this source code.  This source code is provided without any express or implied warranties whatsoever.

 *   Because of the diversity of conditions and hardware under which this source code may be used, no warranty of

 *   fitness for a particular purpose is offered. The user is advised to test the source code thoroughly before

 *   relying on it. The user must assume the entire risk of using the source code.

**/

 

/**

 * Author: Jonathan Kaufmann (jkaufmann@econtrols.com)

 * Company: EControls, Inc. (http://www.econtrols.com, http://www.CANCapture.com)

 * Date: June 2, 2009

 * Description:

 *      This file implements a trivial example for how to transmit a multipacket message

 *   using the J1939 transport protocol.  The example transmits one

 *   Broadcast Announce Message (BAM) sequence for the respective multipacket data

 *   that is filled in the mpSA, mpPGN, and mpData variables.

 *

**/

 

/********* Function TransmitBAM ***********************************

 * Transmits one sequence of BAM packets.

 *

 * BAM = Broadcast Announce Message.  It is a multipacket message

 * defined by the SAE J1939 Transport prototol for sending

 * messages longer than 8 bytes to all (global) devices on the

 * network

 *

 * block: Script block object that will be used to transmit message

 *

 * outPort: Script block port to transmit message out (1,2, or 3)

 *

 * SA: source address to use for BAM

 *

 * PGN: Parameter Group Number of respective message being

 *      transmitted

 *

 * data: Array of data to be sent for multipacket message. Should

 *       be greater than 8

 *

 ******************************************************************/

void TransmitBAM(ScriptBlock block, uint8 outPort, uint8 mpSA, uint32 mpPGN, uint8[] mpData)

{

    int arrlen = mpData.length();  //retrieve data length

    int packetcount = (arrlen / 7) + 1; //calculate number of TP.DT packets that will be sent

 

    if (arrlen < 8) {

        block.PrintOutputText("No need for multipacket message with data length = " + arrlen, true, false, false, true);

        return;

    }

    if (packetcount > 255) {

        block.PrintOutputText("Multipacket message too long" + arrlen, true, false, false, true);

        return;

    }

 

    //Now fill the BAM packet with proper values

    Message bam;

    bam.Set11Bit(0);

    bam.SetDataLength(8);

    bam.SetPGN(60416);  //TP.CM.xx packet

    bam.SetPS(255);  //BAM is inheritely to global address

    bam.SetSA(mpSA);  //set SA

 

    //Now fill the BAM variables

    bam.SetData(0, 32);                      //Byte 1 is Control Byte (TP.CM): 32=BAM

    bam.SetData(1, arrlen & 0xFF);          //Byte 2 and 3 is total message size, J1939 is LSB first

    bam.SetData(2, (arrlen >> 8) & 0xFF);    //

    bam.SetData(3, (arrlen / 7) + 1);        //Byte 3 is total number of packets

    bam.SetData(4, 255);                      //Byte 4 is Maximun number of packets

    bam.SetData(5, mpPGN & 0xFF);              //Byte 5, 6 and 7 is PGN of transmitted MP message

    bam.SetData(6, (mpPGN >> 8) & 0xFF);    //

    bam.SetData(7, (mpPGN >> 16) & 0xFF);

    block.SendMessage(1, bam);  //and send the packet

 

    //Prep our TP.DT packet

    Message tpdt;

    tpdt.Set11Bit(0);

    tpdt.SetDataLength(8);  //This packet is always 8 bytes, filled with 255's when <8

    tpdt.SetPGN(60160); //TP.DT

    tpdt.SetPS(255); //BAM is global address

    tpdt.SetSA(mpSA);

 

    //Now send all the necessary TP.DT packets

    int i;

    int tpdt_count = 1;

    int dataPos = 0;

    int len;

    while (arrlen > 0) {

        len = arrlen;    //retrieve the length of next packet

        if (len > 7)

            len = 7;

        arrlen -= len;

 

        //Fill data

        tpdt.SetData(0, tpdt_count++);       

        for (i = 0; i < len; ++i) {

            tpdt.SetData(i + 1, mpData[dataPos]);

            dataPos++;

        }

        //Pad remaining bytes w/ 255 (will only happen on our last packet)

        for (; i < 7; ++i) {

            tpdt.SetData(i + 1, 255);

        }

 

        block.SendMessage(outPort, tpdt);

    }   

}

 

/********* Function OnStartCapture **********************************

 * Event callback that is called by the framework every time the

 * user clicks the "Start Capture" button.

 *

 * Simply clear the output error window in this case

 *

 ******************************************************************/

void OnStartCapture(ScriptBlock block)

{

    block.ClearOutputText(); //Clear this script's output window

}

 

/********* Function OnStartCapture **********************************

 * Event callback that is called by the framework every time a 

 * message is received by one of the input ports on the respective

 * script block

 *

 * This simply calls TransmitBAM once for every packet that is

 * received

 *

 ******************************************************************/

void OnReceiveMessage(uint8 inPort, ScriptBlock block, Message &msg)

{

    //*********************************************************************************   

    // Fill information about our MultiPacket message.

    // mpPGN is the PGN of the transmitted message

    // mpData is an array the holds the data for our multipacket message

    // mpSA is the source address we are pretending to be

    //*********************************************************************************   

    uint8 mpSA = 0;  //ECU

    uint32 mpPGN = 65226;

    uint8[] mpData(10); 

    mpData[0] = 1;

    mpData[1] = 2;

    mpData[2] = 3;

    mpData[3] = 4;

    mpData[4] = 5;

    mpData[5] = 6;

    mpData[6] = 7;

    mpData[7] = 8;

    mpData[8] = 9;

    mpData[9] = 10;

    //*********************************************************************************   

 

    TransmitBAM(block, 1, mpSA, mpPGN, mpData);

 

}