nuttx-apps/modbus/functions/mbfuncinput.c

139 lines
4.9 KiB
C

/****************************************************************************
* apps/functions/mbfuncinput.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"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#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)
/****************************************************************************
* External Function Prototypes
****************************************************************************/
eMBException prveMBError2Exception(eMBErrorCode eErrorCode);
/****************************************************************************
* Public Functions
****************************************************************************/
#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