FreeModbus: WIN32TCP/demo.cpp

/*
 * FreeModbus Libary: Win32 Demo Application
 * Copyright (C) 2006 Christian Walter <wolti@sil.at>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * File: $Id: demo.cpp,v 1.2 2006/06/26 19:24:07 wolti Exp $
 */

#include "stdafx.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"

/* ----------------------- Defines ------------------------------------------*/
#define PROG            _T("freemodbus")

#define REG_INPUT_START 1000
#define REG_INPUT_NREGS 4
#define REG_HOLDING_START 2000
#define REG_HOLDING_NREGS 130

/* ----------------------- Static variables ---------------------------------*/
static USHORT   usRegInputStart = REG_INPUT_START;
static USHORT   usRegInputBuf[REG_INPUT_NREGS];
static USHORT   usRegHoldingStart = REG_HOLDING_START;
static USHORT   usRegHoldingBuf[REG_HOLDING_NREGS];

static HANDLE   hPollThread;
static CRITICAL_SECTION hPollLock;
static enum ThreadState
{
    STOPPED,
    RUNNING,
    SHUTDOWN
} ePollThreadState;

/* ----------------------- Static functions ---------------------------------*/
static BOOL     bCreatePollingThread( void );
static enum ThreadState eGetPollingThreadState( void );
static void     eSetPollingThreadState( enum ThreadState eNewState );
static DWORD WINAPI dwPollingThread( LPVOID lpParameter );

/* ----------------------- Start implementation -----------------------------*/
int
_tmain( int argc, _TCHAR * argv[] )
{
    int             iExitCode;
    TCHAR           cCh;
    BOOL            bDoExit;

    if( eMBTCPInit( MB_TCP_PORT_USE_DEFAULT ) != MB_ENOERR )
    {
        _ftprintf( stderr, _T( "%s: can't initialize modbus stack!\r\n" ), PROG );
        iExitCode = EXIT_FAILURE;
    }
    else
    {
        /* Create synchronization primitives and set the current state
         * of the thread to STOPPED.
         */
        InitializeCriticalSection( &hPollLock );
        eSetPollingThreadState( STOPPED );

        /* CLI interface. */
        _tprintf( _T( "Type 'q' for quit or 'h' for help!\r\n" ) );
        bDoExit = FALSE;
        do
        {
            _tprintf( _T( "> " ) );
            cCh = _gettchar(  );
            switch ( cCh )
            {
            case _TCHAR( 'q' ):
                bDoExit = TRUE;
                break;
            case _TCHAR( 'd' ):
                eSetPollingThreadState( SHUTDOWN );
                break;
            case _TCHAR( 'e' ):
                if( bCreatePollingThread(  ) != TRUE )
                {
                    _tprintf( _T( "Can't start protocol stack! Already running?\r\n" ) );
                }
                break;
            case _TCHAR( 's' ):
                switch ( eGetPollingThreadState(  ) )
                {
                case RUNNING:
                    _tprintf( _T( "Protocol stack is running.\r\n" ) );
                    break;
                case STOPPED:
                    _tprintf( _T( "Protocol stack is stopped.\r\n" ) );
                    break;
                case SHUTDOWN:
                    _tprintf( _T( "Protocol stack is shuting down.\r\n" ) );
                    break;
                }
                break;
            case _TCHAR( 'h' ):
                _tprintf( _T( "FreeModbus demo application help:\r\n" ) );
                _tprintf( _T( "  'd' ... disable protocol stack.\r\n" ) );
                _tprintf( _T( "  'e' ... enabled the protocol stack\r\n" ) );
                _tprintf( _T( "  's' ... show current status\r\n" ) );
                _tprintf( _T( "  'q' ... quit applicationr\r\n" ) );
                _tprintf( _T( "  'h' ... this information\r\n" ) );
                _tprintf( _T( "\r\n" ) );
                _tprintf( _T( "Copyright 2006 Christian Walter <wolti@sil.at>\r\n" ) );
                break;
            default:
                if( cCh != _TCHAR('\n') )
                {
                    _tprintf( _T( "illegal command '%c'!\r\n" ), cCh );
                }
                break;
            }

            /* eat up everything untill return character. */
            while( cCh != '\n' )
            {
                cCh = _gettchar(  );
            }
        }
        while( !bDoExit );

        /* Release hardware resources. */
        ( void )eMBClose(  );
        iExitCode = EXIT_SUCCESS;
    }
    return iExitCode;
}

BOOL
bCreatePollingThread( void )
{
    BOOL            bResult;

    if( eGetPollingThreadState(  ) == STOPPED )
    {
        if( ( hPollThread = CreateThread( NULL, 0, dwPollingThread, NULL, 0, NULL ) ) == NULL )
        {
            /* Can't create the polling thread. */
            bResult = FALSE;
        }
        else
        {
            bResult = TRUE;
        }
    }
    else
    {
        bResult = FALSE;
    }

    return bResult;
}

DWORD           WINAPI
dwPollingThread( LPVOID lpParameter )
{
    eSetPollingThreadState( RUNNING );

    if( eMBEnable(  ) == MB_ENOERR )
    {
        do
        {
            if( eMBPoll(  ) != MB_ENOERR )
                break;
        }
        while( eGetPollingThreadState(  ) != SHUTDOWN );
    }

    ( void )eMBDisable(  );

    eSetPollingThreadState( STOPPED );

    return 0;
}

enum ThreadState
eGetPollingThreadState(  )
{
    enum ThreadState eCurState;

    EnterCriticalSection( &hPollLock );
    eCurState = ePollThreadState;
    LeaveCriticalSection( &hPollLock );

    return eCurState;
}

void
eSetPollingThreadState( enum ThreadState eNewState )
{
    EnterCriticalSection( &hPollLock );
    ePollThreadState = eNewState;
    LeaveCriticalSection( &hPollLock );
}

eMBErrorCode
eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs )
{
    eMBErrorCode    eStatus = MB_ENOERR;
    int             iRegIndex;

    if( ( usAddress >= REG_INPUT_START )
        && ( usAddress + usNRegs <= REG_INPUT_START + REG_INPUT_NREGS ) )
    {
        iRegIndex = ( int )( usAddress - usRegInputStart );
        while( usNRegs > 0 )
        {
            *pucRegBuffer++ = ( unsigned char )( usRegInputBuf[iRegIndex] >> 8 );
            *pucRegBuffer++ = ( unsigned char )( usRegInputBuf[iRegIndex] & 0xFF );
            iRegIndex++;
            usNRegs--;
        }
    }
    else
    {
        eStatus = MB_ENOREG;
    }

    return eStatus;
}

eMBErrorCode
eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs, eMBRegisterMode eMode )
{
    eMBErrorCode    eStatus = MB_ENOERR;
    int             iRegIndex;

    if( ( usAddress >= REG_HOLDING_START ) &&
        ( usAddress + usNRegs <= REG_HOLDING_START + REG_HOLDING_NREGS ) )
    {
        iRegIndex = ( int )( usAddress - usRegHoldingStart );
        switch ( eMode )
        {
            /* Pass current register values to the protocol stack. */
        case MB_REG_READ:
            while( usNRegs > 0 )
            {
                *pucRegBuffer++ = ( UCHAR ) ( usRegHoldingBuf[iRegIndex] >> 8 );
                *pucRegBuffer++ = ( UCHAR ) ( usRegHoldingBuf[iRegIndex] & 0xFF );
                iRegIndex++;
                usNRegs--;
            }
            break;

            /* Update current register values with new values from the
             * protocol stack. */
        case MB_REG_WRITE:
            while( usNRegs > 0 )
            {
                usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
                usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
                iRegIndex++;
                usNRegs--;
            }
        }
    }
    else
    {
        eStatus = MB_ENOREG;
    }
    return eStatus;
}


eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils, eMBRegisterMode eMode )
{
    return MB_ENOREG;
}

eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
    return MB_ENOREG;
}