Diff: ModBus/mb.cpp

Revision:

0:f54e9507171b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ModBus/mb.cpp	Mon Dec 05 22:49:02 2011 +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;
+}