Cam Marshall
Port of the FreeModbus Libary for mbed
Diff: mb.cpp
- Revision:
- 0:0453a0a7e500
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mb.cpp Thu Apr 15 12:10:34 2010 +0000
@@ -0,0 +1,357 @@
+/*
+ * 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"
+#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 eMBMode eMBCurrentMode;
+
+static enum {
+ STATE_ENABLED,
+ STATE_DISABLED,
+ STATE_NOT_INITIALIZED
+} eMBState = STATE_NOT_INITIALIZED;
+
+/* Functions pointer which are initialized in eMBInit( ). Depending on the
+ * mode (RTU or ASCII) the are set to the correct implementations.
+ */
+static peMBFrameSend peMBFrameSendCur;
+static pvMBFrameStart pvMBFrameStartCur;
+static pvMBFrameStop pvMBFrameStopCur;
+static peMBFrameReceive peMBFrameReceiveCur;
+static pvMBFrameClose pvMBFrameCloseCur;
+
+/* Callback functions required by the porting layer. They are called when
+ * an external event has happend which includes a timeout or the reception
+ * or transmission of a character.
+ */
+BOOL( *pxMBFrameCBByteReceived ) ( void );
+BOOL( *pxMBFrameCBTransmitterEmpty ) ( void );
+BOOL( *pxMBPortCBTimerExpired ) ( void );
+
+BOOL( *pxMBFrameCBReceiveFSMCur ) ( void );
+BOOL( *pxMBFrameCBTransmitFSMCur ) ( void );
+
+/* An array of Modbus functions handlers which associates Modbus function
+ * codes with implementing functions.
+ */
+static xMBFunctionHandler xFuncHandlers[MB_FUNC_HANDLERS_MAX] = {
+#if MB_FUNC_OTHER_REP_SLAVEID_ENABLED > 0
+ {MB_FUNC_OTHER_REPORT_SLAVEID, eMBFuncReportSlaveID},
+#endif
+#if MB_FUNC_READ_INPUT_ENABLED > 0
+ {MB_FUNC_READ_INPUT_REGISTER, eMBFuncReadInputRegister},
+#endif
+#if MB_FUNC_READ_HOLDING_ENABLED > 0
+ {MB_FUNC_READ_HOLDING_REGISTER, eMBFuncReadHoldingRegister},
+#endif
+#if MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED > 0
+ {MB_FUNC_WRITE_MULTIPLE_REGISTERS, eMBFuncWriteMultipleHoldingRegister},
+#endif
+#if MB_FUNC_WRITE_HOLDING_ENABLED > 0
+ {MB_FUNC_WRITE_REGISTER, eMBFuncWriteHoldingRegister},
+#endif
+#if MB_FUNC_READWRITE_HOLDING_ENABLED > 0
+ {MB_FUNC_READWRITE_MULTIPLE_REGISTERS, eMBFuncReadWriteMultipleHoldingRegister},
+#endif
+#if MB_FUNC_READ_COILS_ENABLED > 0
+ {MB_FUNC_READ_COILS, eMBFuncReadCoils},
+#endif
+#if MB_FUNC_WRITE_COIL_ENABLED > 0
+ {MB_FUNC_WRITE_SINGLE_COIL, eMBFuncWriteCoil},
+#endif
+#if MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED > 0
+ {MB_FUNC_WRITE_MULTIPLE_COILS, eMBFuncWriteMultipleCoils},
+#endif
+#if MB_FUNC_READ_DISCRETE_INPUTS_ENABLED > 0
+ {MB_FUNC_READ_DISCRETE_INPUTS, eMBFuncReadDiscreteInputs},
+#endif
+};
+
+/* ----------------------- Start implementation -----------------------------*/
+eMBErrorCode
+eMBInit( eMBMode eMode, 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;
+
+ switch ( eMode ) {
+#if MB_RTU_ENABLED > 0
+ case MB_RTU:
+ pvMBFrameStartCur = eMBRTUStart;
+ pvMBFrameStopCur = eMBRTUStop;
+ peMBFrameSendCur = eMBRTUSend;
+ peMBFrameReceiveCur = eMBRTUReceive;
+ pvMBFrameCloseCur = MB_PORT_HAS_CLOSE ? vMBPortClose : NULL;
+ pxMBFrameCBByteReceived = xMBRTUReceiveFSM;
+ pxMBFrameCBTransmitterEmpty = xMBRTUTransmitFSM;
+ pxMBPortCBTimerExpired = xMBRTUTimerT35Expired;
+
+ eStatus = eMBRTUInit( ucMBAddress, ucPort, ulBaudRate, eParity );
+ break;
+#endif
+#if MB_ASCII_ENABLED > 0
+ case MB_ASCII:
+ pvMBFrameStartCur = eMBASCIIStart;
+ pvMBFrameStopCur = eMBASCIIStop;
+ peMBFrameSendCur = eMBASCIISend;
+ peMBFrameReceiveCur = eMBASCIIReceive;
+ pvMBFrameCloseCur = MB_PORT_HAS_CLOSE ? vMBPortClose : NULL;
+ pxMBFrameCBByteReceived = xMBASCIIReceiveFSM;
+ pxMBFrameCBTransmitterEmpty = xMBASCIITransmitFSM;
+ pxMBPortCBTimerExpired = xMBASCIITimerT1SExpired;
+
+ eStatus = eMBASCIIInit( ucMBAddress, ucPort, ulBaudRate, eParity );
+ break;
+#endif
+ default:
+ eStatus = MB_EINVAL;
+ }
+
+ if ( eStatus == MB_ENOERR ) {
+ if ( !xMBPortEventInit( ) ) {
+ /* port dependent event module initalization failed. */
+ eStatus = MB_EPORTERR;
+ } else {
+ eMBCurrentMode = eMode;
+ eMBState = STATE_DISABLED;
+ }
+ }
+ }
+ return eStatus;
+}
+
+#if MB_TCP_ENABLED > 0
+eMBErrorCode
+eMBTCPInit( USHORT ucTCPPort ) {
+ eMBErrorCode eStatus = MB_ENOERR;
+
+ if ( ( eStatus = eMBTCPDoInit( ucTCPPort ) ) != MB_ENOERR ) {
+ eMBState = STATE_DISABLED;
+ } else if ( !xMBPortEventInit( ) ) {
+ /* Port dependent event module initalization failed. */
+ eStatus = MB_EPORTERR;
+ } else {
+ pvMBFrameStartCur = eMBTCPStart;
+ pvMBFrameStopCur = eMBTCPStop;
+ peMBFrameReceiveCur = eMBTCPReceive;
+ peMBFrameSendCur = eMBTCPSend;
+ pvMBFrameCloseCur = MB_PORT_HAS_CLOSE ? vMBTCPPortClose : NULL;
+ ucMBAddress = MB_TCP_PSEUDO_ADDRESS;
+ eMBCurrentMode = MB_TCP;
+ eMBState = STATE_DISABLED;
+ }
+ return eStatus;
+}
+#endif
+
+
+eMBErrorCode
+eMBRegisterCB( UCHAR ucFunctionCode, pxMBFunctionHandler pxHandler ) {
+ int i;
+ eMBErrorCode eStatus;
+
+ if ( ( 0 < ucFunctionCode ) && ( ucFunctionCode <= 127 ) ) {
+ ENTER_CRITICAL_SECTION( );
+ if ( pxHandler != NULL ) {
+ for ( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ ) {
+ if ( ( xFuncHandlers[i].pxHandler == NULL ) ||
+ ( xFuncHandlers[i].pxHandler == pxHandler ) ) {
+ xFuncHandlers[i].ucFunctionCode = ucFunctionCode;
+ xFuncHandlers[i].pxHandler = pxHandler;
+ break;
+ }
+ }
+ eStatus = ( i != MB_FUNC_HANDLERS_MAX ) ? MB_ENOERR : MB_ENORES;
+ } else {
+ for ( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ ) {
+ if ( xFuncHandlers[i].ucFunctionCode == ucFunctionCode ) {
+ xFuncHandlers[i].ucFunctionCode = 0;
+ xFuncHandlers[i].pxHandler = NULL;
+ break;
+ }
+ }
+ /* Remove can't fail. */
+ eStatus = MB_ENOERR;
+ }
+ EXIT_CRITICAL_SECTION( );
+ } else {
+ eStatus = MB_EINVAL;
+ }
+ return eStatus;
+}
+
+
+eMBErrorCode
+eMBClose( void ) {
+ eMBErrorCode eStatus = MB_ENOERR;
+
+ if ( eMBState == STATE_DISABLED ) {
+ if ( pvMBFrameCloseCur != NULL ) {
+ pvMBFrameCloseCur( );
+ }
+ } else {
+ eStatus = MB_EILLSTATE;
+ }
+ return eStatus;
+}
+
+eMBErrorCode
+eMBEnable( void ) {
+ eMBErrorCode eStatus = MB_ENOERR;
+
+ if ( eMBState == STATE_DISABLED ) {
+ /* Activate the protocol stack. */
+ pvMBFrameStartCur( );
+ eMBState = STATE_ENABLED;
+ } else {
+ eStatus = MB_EILLSTATE;
+ }
+ return eStatus;
+}
+
+eMBErrorCode
+eMBDisable( void ) {
+ eMBErrorCode eStatus;
+
+ if ( eMBState == STATE_ENABLED ) {
+ pvMBFrameStopCur( );
+ eMBState = STATE_DISABLED;
+ eStatus = MB_ENOERR;
+ } else if ( eMBState == STATE_DISABLED ) {
+ eStatus = MB_ENOERR;
+ } else {
+ eStatus = MB_EILLSTATE;
+ }
+ return eStatus;
+}
+
+eMBErrorCode
+eMBPoll( void ) {
+ static UCHAR *ucMBFrame;
+ static UCHAR ucRcvAddress;
+ static UCHAR ucFunctionCode;
+ static USHORT usLength;
+ static eMBException eException;
+
+ int i;
+ eMBErrorCode eStatus = MB_ENOERR;
+ eMBEventType eEvent;
+
+ /* Check if the protocol stack is ready. */
+ if ( eMBState != STATE_ENABLED ) {
+ return MB_EILLSTATE;
+ }
+
+ /* 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 = peMBFrameReceiveCur( &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 ) ) {
+ ( void )xMBPortEventPost( EV_EXECUTE );
+ }
+ }
+ break;
+
+ case EV_EXECUTE:
+ ucFunctionCode = ucMBFrame[MB_PDU_FUNC_OFF];
+ eException = MB_EX_ILLEGAL_FUNCTION;
+
+
+ for ( i = 0; i < MB_FUNC_HANDLERS_MAX; i++ ) {
+ /* No more function handlers registered. Abort. */
+ if ( xFuncHandlers[i].ucFunctionCode == 0 ) {
+ break;
+ } else if ( xFuncHandlers[i].ucFunctionCode == ucFunctionCode ) {
+ eException = xFuncHandlers[i].pxHandler( ucMBFrame, &usLength );
+ break;
+ }
+ }
+
+ /* 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 = peMBFrameSendCur( ucMBAddress, ucMBFrame, usLength );
+ }
+ break;
+
+ case EV_FRAME_SENT:
+ break;
+ }
+ }
+ return MB_ENOERR;
+}