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/*
* 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: mbfuncinput.c,v 1.10 2007/09/12 10:15:56 wolti Exp $
*/
/* ----------------------- System includes ----------------------------------*/
#include <nuttx/config.h>
#include <stdlib.h>
#include <string.h>
/* ----------------------- Platform includes --------------------------------*/
#include "port.h"
/* ----------------------- Modbus includes ----------------------------------*/
#include <apps/modbus/mb.h>
#include <apps/modbus/mbframe.h>
#include <apps/modbus/mbproto.h>
/* ----------------------- Defines ------------------------------------------*/
#define MB_PDU_FUNC_READ_ADDR_OFF ( MB_PDU_DATA_OFF )
#define MB_PDU_FUNC_READ_REGCNT_OFF ( MB_PDU_DATA_OFF + 2 )
#define MB_PDU_FUNC_READ_SIZE ( 4 )
#define MB_PDU_FUNC_READ_REGCNT_MAX ( 0x007D )
#define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF ( MB_PDU_DATA_OFF )
/* ----------------------- Static functions ---------------------------------*/
eMBException prveMBError2Exception( eMBErrorCode eErrorCode );
/* ----------------------- Start implementation -----------------------------*/
#ifdef CONFIG_MB_FUNC_READ_INPUT_ENABLED
eMBException
eMBFuncReadInputRegister( uint8_t * pucFrame, uint16_t * usLen )
{
uint16_t usRegAddress;
uint16_t usRegCount;
uint8_t *pucFrameCur;
eMBException eStatus = MB_EX_NONE;
eMBErrorCode eRegStatus;
if( *usLen == ( MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN ) )
{
usRegAddress = ( uint16_t )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF] << 8 );
usRegAddress |= ( uint16_t )( pucFrame[MB_PDU_FUNC_READ_ADDR_OFF + 1] );
usRegAddress++;
usRegCount = ( uint16_t )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF] << 8 );
usRegCount |= ( uint16_t )( pucFrame[MB_PDU_FUNC_READ_REGCNT_OFF + 1] );
/* Check if the number of registers to read is valid. If not
* return Modbus illegal data value exception.
*/
if( ( usRegCount >= 1 )
&& ( usRegCount < MB_PDU_FUNC_READ_REGCNT_MAX ) )
{
/* Set the current PDU data pointer to the beginning. */
pucFrameCur = &pucFrame[MB_PDU_FUNC_OFF];
*usLen = MB_PDU_FUNC_OFF;
/* First byte contains the function code. */
*pucFrameCur++ = MB_FUNC_READ_INPUT_REGISTER;
*usLen += 1;
/* Second byte in the response contain the number of bytes. */
*pucFrameCur++ = ( uint8_t )( usRegCount * 2 );
*usLen += 1;
eRegStatus =
eMBRegInputCB( pucFrameCur, usRegAddress, usRegCount );
/* If an error occured convert it into a Modbus exception. */
if( eRegStatus != MB_ENOERR )
{
eStatus = prveMBError2Exception( eRegStatus );
}
else
{
*usLen += usRegCount * 2;
}
}
else
{
eStatus = MB_EX_ILLEGAL_DATA_VALUE;
}
}
else
{
/* Can't be a valid read input register request because the length
* is incorrect. */
eStatus = MB_EX_ILLEGAL_DATA_VALUE;
}
return eStatus;
}
#endif
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