Source Code File:"mb.c"

/* 
 * 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: mb.c,v 1.27 2007/02/18 23:45:41 wolti Exp $
 */

/* ----------------------- System includes ----------------------------------*/
#include "stdlib.h"
#include "string.h"

/* ----------------------- Platform includes --------------------------------*/
#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbconfig.h"
#include "mbframe.h"
#include "mbproto.h"
#include "mbfunc.h"

#ifdef USING_NOVO
#include "novocfg_pic18t3e1ts2.h"
#include "novo.h"
#endif

#include "mbport.h"
#if MB_RTU_ENABLED == 1
#include "mbrtu.h"
#endif
#if MB_ASCII_ENABLED == 1
#include "mbascii.h"
#endif
#if MB_TCP_ENABLED == 1
#include "mbtcp.h"
#endif

#ifndef MB_PORT_HAS_CLOSE
#define MB_PORT_HAS_CLOSE 0
#endif

/* ----------------------- Static variables ---------------------------------*/
static UCHAR    ucMBAddress;
static EMBSTATE eMBState;

/* ----------------------- Start implementation -----------------------------*/
eMBErrorCode
eMBInit( UCHAR ucSlaveAddress, UCHAR ucPort, ULONG ulBaudRate, eMBParity eParity )
{
    eMBErrorCode    eStatus = MB_ENOERR;

    /* check preconditions */
    if( ( ucSlaveAddress == MB_ADDRESS_BROADCAST ) ||
        ( ucSlaveAddress < MB_ADDRESS_MIN ) || ( ucSlaveAddress > MB_ADDRESS_MAX ) )
    {
        eStatus = MB_EINVAL;
    }
    else
    {
        ucMBAddress = ucSlaveAddress;

        eStatus = eMBRTUInit( ucMBAddress, ucPort, ulBaudRate, eParity );

        if( eStatus == MB_ENOERR )
        {
            if( !xMBPortEventInit(  ) )
            {
                /* port dependent event module initalization failed. */
                eStatus = MB_EPORTERR;
            }
            else
            {
                eMBState = STATE_DISABLED;
            }
        }
    }
    return eStatus;
}




eMBErrorCode
eMBClose( void )
{
    eMBErrorCode    eStatus = MB_ENOERR;

    if( eMBState == STATE_DISABLED )
    {
         vMBPortClose(  );
    }
    else
    {
        eStatus = MB_EILLSTATE;
    }
    return eStatus;
}

eMBErrorCode
eMBEnable( void )
{
    eMBErrorCode    eStatus = MB_ENOERR;

    if( eMBState == STATE_DISABLED )
    {
        /* Activate the protocol stack. */
        eMBRTUStart(  );
        eMBState = STATE_ENABLED;
    }
    else
    {
        eStatus = MB_EILLSTATE;
    }
    return eStatus;
}

eMBErrorCode
eMBDisable( void )
{
    eMBErrorCode    eStatus;

    if( eMBState == STATE_ENABLED )
    {
        eMBRTUStop(  );
        eMBState = STATE_DISABLED;
        eStatus = MB_ENOERR;
    }
    else if( eMBState == STATE_DISABLED )
    {
        eStatus = MB_ENOERR;
    }
    else
    {
        eStatus = MB_EILLSTATE;
    }
    return eStatus;
}

void
TaskMBPoll()
{
    static UCHAR   *ucMBFrame;
    static UCHAR    ucRcvAddress;
    static UCHAR    ucFunctionCode;
    static USHORT   usLength;
    static eMBException eException;

    int             i;
    eMBErrorCode    eStatus = MB_ENOERR;
    eMBEventType    eEvent;

#ifdef USING_NOVO       
    while(1)
    {
#endif    
       /* Check if the protocol stack is ready. */
       if( eMBState != STATE_ENABLED )
       {
#ifdef USING_NOVO
           Sys_Yield();
#else           
           return;
#endif           
       }
   
       /* Check if there is a event available. If not return control to caller.
        * Otherwise we will handle the event. */
       if( xMBPortEventGet( &eEvent ) == TRUE )
       {
           switch ( eEvent )
           {
           case EV_READY:
               break;
   
           case EV_FRAME_RECEIVED:
               eStatus = eMBRTUReceive( &ucRcvAddress, &ucMBFrame, &usLength );
               if( eStatus == MB_ENOERR )
               {
                   /* Check if the frame is for us. If not ignore the frame. */
                   if( ( ucRcvAddress == ucMBAddress ) || ( ucRcvAddress == MB_ADDRESS_BROADCAST ) )
                   {
                     ENTER_CRITICAL_SECTION();
                     ( void )xMBPortEventPost( EV_EXECUTE );
                     EXIT_CRITICAL_SECTION();
                   }
               }
               break;
   
           case EV_EXECUTE:
               ucFunctionCode = ucMBFrame[MB_PDU_FUNC_OFF];
               eException = MB_EX_ILLEGAL_FUNCTION;
               switch( ucFunctionCode )
               {
#if MB_FUNC_OTHER_REP_SLAVEID_ENABLED > 0
                  case MB_FUNC_OTHER_REPORT_SLAVEID:
                     eException = eMBFuncReportSlaveID( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_READ_INPUT_ENABLED > 0
                  case MB_FUNC_READ_INPUT_REGISTER:
                     eException = eMBFuncReadInputRegister( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_READ_HOLDING_ENABLED > 0
                  case MB_FUNC_READ_HOLDING_REGISTER:
                     eException = eMBFuncReadHoldingRegister( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED > 0
                  case MB_FUNC_WRITE_MULTIPLE_REGISTERS:
                     eException = eMBFuncWriteMultipleHoldingRegister( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_WRITE_HOLDING_ENABLED > 0
                  case MB_FUNC_WRITE_REGISTER:
                     eException = eMBFuncWriteHoldingRegister( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_READWRITE_HOLDING_ENABLED > 0
                  case MB_FUNC_READWRITE_MULTIPLE_REGISTERS:
                     eException = eMBFuncReadWriteMultipleHoldingRegister( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_READ_COILS_ENABLED > 0
                  case MB_FUNC_READ_COILS:
                     eException = eMBFuncReadCoils( ucMBFrame, &usLength );
                     break;                  
#endif
#if MB_FUNC_WRITE_COIL_ENABLED > 0
                  case MB_FUNC_WRITE_SINGLE_COIL:
                     eException = eMBFuncWriteCoil( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0
                  case MB_FUNC_WRITE_MULTIPLE_COILS:
                     eException = eMBFuncWriteMultipleCoils( ucMBFrame, &usLength );
                     break;
#endif
#if MB_FUNC_READ_DISCRETE_INPUTS_ENABLED > 0
                  case MB_FUNC_READ_DISCRETE_INPUTS:
                     eException = eMBFuncReadDiscreteInputs( ucMBFrame, &usLength );
                     break;
#endif
               }
   
   
               /* If the request was not sent to the broadcast address we
                * return a reply. */
               if( ucRcvAddress != MB_ADDRESS_BROADCAST )
               {
                   if( eException != MB_EX_NONE )
                   {
                       /* An exception occured. Build an error frame. */
                       usLength = 0;
                       ucMBFrame[usLength++] = ( UCHAR )( ucFunctionCode | MB_FUNC_ERROR );
                       ucMBFrame[usLength++] = eException;
                   }
                   eStatus = eMBRTUSend( ucMBAddress, ucMBFrame, usLength );
               }
               break;
   
           case EV_FRAME_SENT:
               break;
           }
       }
#ifdef USING_NOVO       
    }
#endif    
}

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