123 lines
4.7 KiB
C
123 lines
4.7 KiB
C
/*
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* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
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* Copyright (c) 2006 Christian Walter <wolti@sil.at>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* File: $Id: mbfuncinput.c,v 1.10 2007/09/12 10:15:56 wolti Exp $
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*/
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/* ----------------------- System includes ----------------------------------*/
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#include "stdlib.h"
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#include "string.h"
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/* ----------------------- Platform includes --------------------------------*/
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#include "port.h"
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/* ----------------------- Modbus includes ----------------------------------*/
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#include "mb.h"
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#include "mbframe.h"
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#include "mbproto.h"
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#include "mbconfig.h"
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/* ----------------------- Defines ------------------------------------------*/
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#define MB_PDU_FUNC_READ_ADDR_OFF ( MB_PDU_DATA_OFF )
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#define MB_PDU_FUNC_READ_REGCNT_OFF ( MB_PDU_DATA_OFF + 2 )
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#define MB_PDU_FUNC_READ_SIZE ( 4 )
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#define MB_PDU_FUNC_READ_REGCNT_MAX ( 0x007D )
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#define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF ( MB_PDU_DATA_OFF )
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/* ----------------------- Static functions ---------------------------------*/
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eMBException prveMBError2Exception( eMBErrorCode eErrorCode );
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/* ----------------------- Start implementation -----------------------------*/
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#if MB_FUNC_READ_INPUT_ENABLED > 0
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eMBException
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eMBFuncReadInputRegister( UCHAR * pucFrame, USHORT * usLen )
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{
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USHORT usRegAddress;
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USHORT usRegCount;
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UCHAR *pucFrameCur;
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eMBException eStatus = MB_EX_NONE;
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eMBErrorCode eRegStatus;
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if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )
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{
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usRegAddress = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );
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usRegAddress |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );
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usRegAddress++;
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usRegCount = ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF] << 8 );
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usRegCount |= ( USHORT )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF + 1] );
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/* Check if the number of registers to read is valid. If not
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* return Modbus illegal data value exception.
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*/
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if( ( usRegCount >= 1 )
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&& ( usRegCount < MB_PDU_FUNC_READ_REGCNT_MAX ) )
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{
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/* Set the current PDU data pointer to the beginning. */
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pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF];
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*usLen = MB_PDU_FUNC_OFF;
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/* First byte contains the function code. */
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*pucFrameCur++ = MB_FUNC_READ_INPUT_REGISTER;
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*usLen += 1;
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/* Second byte in the response contain the number of bytes. */
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*pucFrameCur++ = ( UCHAR )( usRegCount * 2 );
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*usLen += 1;
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eRegStatus =
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eMBRegInputCB( pucFrameCur, usRegAddress, usRegCount );
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/* If an error occured convert it into a Modbus exception. */
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if( eRegStatus != MB_ENOERR )
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{
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eStatus = prveMBError2Exception( eRegStatus );
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}
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else
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{
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*usLen += usRegCount * 2;
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}
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}
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else
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{
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eStatus = MB_EX_ILLEGAL_DATA_VALUE;
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}
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}
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else
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{
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/* Can't be a valid read input register request because the length
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* is incorrect. */
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eStatus = MB_EX_ILLEGAL_DATA_VALUE;
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}
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return eStatus;
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}
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#endif
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