Tooltron

/* 

 * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.

 * Copyright (c) 2006 Christian Walter <wolti@sil.at>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. The name of the author may not be used to endorse or promote products

 *    derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * File: $Id: mbfunccoils.c,v 1.8 2007/02/18 23:47:16 wolti Exp $

 */

/* ----------------------- System includes ----------------------------------*/

#include "stdlib.h"

#include "string.h"

/* ----------------------- Platform includes --------------------------------*/

#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/

#include "mb.h"

#include "mbframe.h"

#include "mbproto.h"

#include "mbconfig.h"

/* ----------------------- Defines ------------------------------------------*/

#define MB_PDU_FUNC_READ_ADDR_OFF           ( MB_PDU_DATA_OFF )

#define MB_PDU_FUNC_READ_COILCNT_OFF        ( MB_PDU_DATA_OFF + 2 )

#define MB_PDU_FUNC_READ_SIZE               ( 4 )

#define MB_PDU_FUNC_READ_COILCNT_MAX        ( 0x07D0 )

#define MB_PDU_FUNC_WRITE_ADDR_OFF          ( MB_PDU_DATA_OFF )

#define MB_PDU_FUNC_WRITE_VALUE_OFF         ( MB_PDU_DATA_OFF + 2 )

#define MB_PDU_FUNC_WRITE_SIZE              ( 4 )

#define MB_PDU_FUNC_WRITE_MUL_ADDR_OFF      ( MB_PDU_DATA_OFF )

#define MB_PDU_FUNC_WRITE_MUL_COILCNT_OFF   ( MB_PDU_DATA_OFF + 2 )

#define MB_PDU_FUNC_WRITE_MUL_BYTECNT_OFF   ( MB_PDU_DATA_OFF + 4 )

#define MB_PDU_FUNC_WRITE_MUL_VALUES_OFF    ( MB_PDU_DATA_OFF + 5 )

#define MB_PDU_FUNC_WRITE_MUL_SIZE_MIN      ( 5 )

#define MB_PDU_FUNC_WRITE_MUL_COILCNT_MAX   ( 0x07B0 )

/* ----------------------- Static functions ---------------------------------*/

eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );

/* ----------------------- Start implementation -----------------------------*/

#if MB_FUNC_READ_COILS_ENABLED > 0

eMBException

eMBFuncReadCoils( UCHAR * pucFrame, USHORT * usLen )

{

    USHORT          usRegAddress;

    USHORT          usCoilCount;

    UCHAR           ucNBytes;

    UCHAR          *pucFrameCur;

    eMBException    eStatus = MB_EX_NONE;

    eMBErrorCode    eRegStatus;

    if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )

    {

        usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );

        usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );

        usRegAddress++;

        usCoilCount = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_COILCNT_OFF] << 8 );

        usCoilCount |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_COILCNT_OFF + 1] );

        /* Check if the number of registers to read is valid. If not

         * return Modbus illegal data value exception. 

         */

        if( ( usCoilCount >= 1 ) &&

            ( usCoilCount < MB_PDU_FUNC_READ_COILCNT_MAX ) )

        {

            /* Set the current PDU data pointer to the beginning. */

            pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF];

            *usLen = MB_PDU_FUNC_OFF;

            /* First byte contains the function code. */

            *pucFrameCur++ = MB_FUNC_READ_COILS;

            *usLen += 1;

            /* Test if the quantity of coils is a multiple of 8. If not last

             * byte is only partially field with unused coils set to zero. */

            if( ( usCoilCount & 0x0007 ) != 0 )

            {

                ucNBytes = ( UCHAR )( usCoilCount / 8 + 1 );

            }

            else

            {

                ucNBytes = ( UCHAR )( usCoilCount / 8 );

            }

            *pucFrameCur++ = ucNBytes;

            *usLen += 1;

            eRegStatus =

                eMBRegCoilsCB( pucFrameCur, usRegAddress, usCoilCount,

                               MB_REG_READ );

            /* If an error occured convert it into a Modbus exception. */

            if( eRegStatus != MB_ENOERR )

            {

                eStatus = prveMBError2Exception( eRegStatus );

            }

            else

            {

                /* The response contains the function code, the starting address

                 * and the quantity of registers. We reuse the old values in the 

                 * buffer because they are still valid. */

                *usLen += ucNBytes;;

            }

        }

        else

        {

            eStatus = MB_EX_ILLEGAL_DATA_VALUE;

        }

    }

    else

    {

        /* Can't be a valid read coil register request because the length

         * is incorrect. */

        eStatus = MB_EX_ILLEGAL_DATA_VALUE;

    }

    return eStatus;

}

#if MB_FUNC_WRITE_COIL_ENABLED > 0

eMBException

eMBFuncWriteCoil( UCHAR * pucFrame, USHORT * usLen )

{

    USHORT          usRegAddress;

    UCHAR           ucBuf[2];

    eMBException    eStatus = MB_EX_NONE;

    eMBErrorCode    eRegStatus;

    if( *usLen == ( MB_PDU_FUNC_WRITE_SIZE + MB_PDU_SIZE_MIN ) )

    {

        usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_ADDR_OFF] << 8 );

        usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_ADDR_OFF + 1] );

        usRegAddress++;

        if( ( pucFrame[MB_PDU_FUNC_WRITE_VALUE_OFF + 1] == 0x00 ) &&

            ( ( pucFrame[MB_PDU_FUNC_WRITE_VALUE_OFF] == 0xFF ) ||

              ( pucFrame[MB_PDU_FUNC_WRITE_VALUE_OFF] == 0x00 ) ) )

        {

            ucBuf[1] = 0;

            if( pucFrame[MB_PDU_FUNC_WRITE_VALUE_OFF] == 0xFF )

            {

                ucBuf[0] = 1;

            }

            else

            {

                ucBuf[0] = 0;

            }

            eRegStatus =

                eMBRegCoilsCB( &ucBuf[0], usRegAddress, 1, MB_REG_WRITE );

            /* If an error occured convert it into a Modbus exception. */

            if( eRegStatus != MB_ENOERR )

            {

                eStatus = prveMBError2Exception( eRegStatus );

            }

        }

        else

        {

            eStatus = MB_EX_ILLEGAL_DATA_VALUE;

        }

    }

    else

    {

        /* Can't be a valid write coil register request because the length

         * is incorrect. */

        eStatus = MB_EX_ILLEGAL_DATA_VALUE;

    }

    return eStatus;

}

#endif

#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0

eMBException

eMBFuncWriteMultipleCoils( UCHAR * pucFrame, USHORT * usLen )

{

    USHORT          usRegAddress;

    USHORT          usCoilCnt;

    UCHAR           ucByteCount;

    UCHAR           ucByteCountVerify;

    eMBException    eStatus = MB_EX_NONE;

    eMBErrorCode    eRegStatus;

    if( *usLen > ( MB_PDU_FUNC_WRITE_SIZE + MB_PDU_SIZE_MIN ) )

    {

        usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_MUL_ADDR_OFF] << 8 );

        usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_MUL_ADDR_OFF + 1] );

        usRegAddress++;

        usCoilCnt = ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_MUL_COILCNT_OFF] << 8 );

        usCoilCnt |= ( USHORT )( pucFrame[MB_PDU_FUNC_WRITE_MUL_COILCNT_OFF + 1] );

        ucByteCount = pucFrame[MB_PDU_FUNC_WRITE_MUL_BYTECNT_OFF];

        /* Compute the number of expected bytes in the request. */

        if( ( usCoilCnt & 0x0007 ) != 0 )

        {

            ucByteCountVerify = ( UCHAR )( usCoilCnt / 8 + 1 );

        }

        else

        {

            ucByteCountVerify = ( UCHAR )( usCoilCnt / 8 );

        }

        if( ( usCoilCnt >= 1 ) &&

            ( usCoilCnt <= MB_PDU_FUNC_WRITE_MUL_COILCNT_MAX ) &&

            ( ucByteCountVerify == ucByteCount ) )

        {

            eRegStatus =

                eMBRegCoilsCB( &pucFrame[MB_PDU_FUNC_WRITE_MUL_VALUES_OFF],

                               usRegAddress, usCoilCnt, MB_REG_WRITE );

            /* If an error occured convert it into a Modbus exception. */

            if( eRegStatus != MB_ENOERR )

            {

                eStatus = prveMBError2Exception( eRegStatus );

            }

            else

            {

                /* The response contains the function code, the starting address

                 * and the quantity of registers. We reuse the old values in the 

                 * buffer because they are still valid. */

                *usLen = MB_PDU_FUNC_WRITE_MUL_BYTECNT_OFF;

            }

        }

        else

        {

            eStatus = MB_EX_ILLEGAL_DATA_VALUE;

        }

    }

    else

    {

        /* Can't be a valid write coil register request because the length

         * is incorrect. */

        eStatus = MB_EX_ILLEGAL_DATA_VALUE;

    }

    return eStatus;

}

#endif

#endif