/****************************************************************************
* apps/modbus/mb.c
*
* FreeModbus Library: 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <string.h>
#include "port.h"
#include "modbus/mb.h"
#include "modbus/mbframe.h"
#include "modbus/mbproto.h"
#include "modbus/mbfunc.h"
#include "modbus/mbport.h"
#ifdef CONFIG_MB_RTU_ENABLED
# include "mbrtu.h"
#endif
#ifdef CONFIG_MB_ASCII_ENABLED
# include "mbascii.h"
#endif
#ifdef CONFIG_MB_TCP_ENABLED
# include "mbtcp.h"
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static uint8_t 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 happened 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[CONFIG_MB_FUNC_HANDLERS_MAX] =
{
#ifdef CONFIG_MB_FUNC_OTHER_REP_SLAVEID_ENABLED
{MB_FUNC_OTHER_REPORT_SLAVEID, eMBFuncReportSlaveID},
#endif
#ifdef CONFIG_MB_FUNC_READ_INPUT_ENABLED
{MB_FUNC_READ_INPUT_REGISTER, eMBFuncReadInputRegister},
#endif
#ifdef CONFIG_MB_FUNC_READ_HOLDING_ENABLED
{MB_FUNC_READ_HOLDING_REGISTER, eMBFuncReadHoldingRegister},
#endif
#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_HOLDING_ENABLED
{MB_FUNC_WRITE_MULTIPLE_REGISTERS, eMBFuncWriteMultipleHoldingRegister},
#endif
#ifdef CONFIG_MB_FUNC_WRITE_HOLDING_ENABLED
{MB_FUNC_WRITE_REGISTER, eMBFuncWriteHoldingRegister},
#endif
#ifdef CONFIG_MB_FUNC_READWRITE_HOLDING_ENABLED
{MB_FUNC_READWRITE_MULTIPLE_REGISTERS, eMBFuncReadWriteMultipleHoldingRegister},
#endif
#ifdef CONFIG_MB_FUNC_READ_COILS_ENABLED
{MB_FUNC_READ_COILS, eMBFuncReadCoils},
#endif
#ifdef CONFIG_MB_FUNC_WRITE_COIL_ENABLED
{MB_FUNC_WRITE_SINGLE_COIL, eMBFuncWriteCoil},
#endif
#ifdef CONFIG_MB_FUNC_WRITE_MULTIPLE_COILS_ENABLED
{MB_FUNC_WRITE_MULTIPLE_COILS, eMBFuncWriteMultipleCoils},
#endif
#ifdef CONFIG_MB_FUNC_READ_DISCRETE_INPUTS_ENABLED
{MB_FUNC_READ_DISCRETE_INPUTS, eMBFuncReadDiscreteInputs},
#endif
};
/****************************************************************************
* Public Functions
****************************************************************************/
eMBErrorCode eMBInit(eMBMode eMode, uint8_t ucSlaveAddress, uint8_t ucPort,
speed_t 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)
{
#ifdef CONFIG_MB_RTU_ENABLED
case MB_RTU:
pvMBFrameStartCur = eMBRTUStart;
pvMBFrameStopCur = eMBRTUStop;
peMBFrameSendCur = eMBRTUSend;
peMBFrameReceiveCur = eMBRTUReceive;
pvMBFrameCloseCur = vMBPortClose;
pxMBFrameCBByteReceived = xMBRTUReceiveFSM;
pxMBFrameCBTransmitterEmpty = xMBRTUTransmitFSM;
pxMBPortCBTimerExpired = xMBRTUTimerT35Expired;
eStatus = eMBRTUInit(ucMBAddress, ucPort, ulBaudRate, eParity);
break;
#endif
#ifdef CONFIG_MB_ASCII_ENABLED
case MB_ASCII:
pvMBFrameStartCur = eMBASCIIStart;
pvMBFrameStopCur = eMBASCIIStop;
peMBFrameSendCur = eMBASCIISend;
peMBFrameReceiveCur = eMBASCIIReceive;
pvMBFrameCloseCur = vMBPortClose;
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 initialization failed. */
eStatus = MB_EPORTERR;
}
else
{
eMBCurrentMode = eMode;
eMBState = STATE_DISABLED;
}
}
}
return eStatus;
}
#ifdef CONFIG_MB_TCP_ENABLED
eMBErrorCode eMBTCPInit(uint16_t ucTCPPort)
{
eMBErrorCode eStatus = MB_ENOERR;
if ((eStatus = eMBTCPDoInit(ucTCPPort)) != MB_ENOERR)
{
eMBState = STATE_DISABLED;
}
else if (!xMBPortEventInit())
{
/* Port dependent event module initialization failed. */
eStatus = MB_EPORTERR;
}
else
{
pvMBFrameStartCur = eMBTCPStart;
pvMBFrameStopCur = eMBTCPStop;
peMBFrameReceiveCur = eMBTCPReceive;
peMBFrameSendCur = eMBTCPSend;
#ifdef CONFIG_MB_HAVE_CLOSE
pvMBFrameCloseCur = vMBTCPPortClose;
#else
pvMBFrameCloseCur = NULL;
#endif
ucMBAddress = MB_TCP_PSEUDO_ADDRESS;
eMBCurrentMode = MB_TCP;
eMBState = STATE_DISABLED;
}
return eStatus;
}
#endif
eMBErrorCode eMBRegisterCB(uint8_t ucFunctionCode, pxMBFunctionHandler pxHandler)
{
eMBErrorCode eStatus;
int i;
if ((0 < ucFunctionCode) && (ucFunctionCode <= 127))
{
ENTER_CRITICAL_SECTION();
if (pxHandler != NULL)
{
for (i = 0; i < CONFIG_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 != CONFIG_MB_FUNC_HANDLERS_MAX) ? MB_ENOERR : MB_ENORES;
}
else
{
for (i = 0; i < CONFIG_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 uint8_t *ucMBFrame;
static uint8_t ucRcvAddress;
static uint8_t ucFunctionCode;
static uint16_t 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))
{
xMBPortEventPost(EV_EXECUTE);
}
}
break;
case EV_EXECUTE:
ucFunctionCode = ucMBFrame[MB_PDU_FUNC_OFF];
eException = MB_EX_ILLEGAL_FUNCTION;
for( i = 0; i < CONFIG_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 occurred. Build an error frame. */
usLength = 0;
ucMBFrame[usLength++] = (uint8_t)(ucFunctionCode | MB_FUNC_ERROR);
ucMBFrame[usLength++] = eException;
}
#ifdef CONFIG_MB_ASCII_ENABLED
if ((eMBCurrentMode == MB_ASCII) && CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS)
{
vMBPortTimersDelay(CONFIG_MB_ASCII_TIMEOUT_WAIT_BEFORE_SEND_MS);
}
#endif
peMBFrameSendCur(ucMBAddress, ucMBFrame, usLength);
}
break;
case EV_FRAME_SENT:
break;
}
}
return MB_ENOERR;
}