Files
esp-modbus/modbus/mb_objects/functions/mbfuncinput.c
2023-12-10 15:30:06 +01:00

101 lines
4.3 KiB
C

/*
* FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
* Copyright (c) 2016, 2017 Nucleron R&D LLC <main@nucleron.ru>
* 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 $
*/
#include <mb_common.h>
#include <mb_proto.h>
#include "mb_slave.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 ---------------------------------*/
mb_exception_t mb_error_to_exception(mb_err_enum_t error_code);
/* ----------------------- Start implementation -----------------------------*/
#if MB_FUNC_READ_INPUT_ENABLED > 0
mb_exception_t mbs_fn_read_input_reg(mb_base_t *inst, uint8_t *frame_ptr, uint16_t *len_buf)
{
uint16_t reg_addr;
uint16_t reg_cnt;
uint8_t *frame_cur;
mb_exception_t status = MB_EX_NONE;
mb_err_enum_t reg_status = MB_EILLFUNC;
if (*len_buf == (MB_PDU_FUNC_READ_SIZE + MB_PDU_SIZE_MIN)) {
reg_addr = (uint16_t)(frame_ptr[MB_PDU_FUNC_READ_ADDR_OFF] << 8);
reg_addr |= (uint16_t)(frame_ptr[MB_PDU_FUNC_READ_ADDR_OFF + 1]);
reg_addr++;
reg_cnt = (uint16_t)(frame_ptr[MB_PDU_FUNC_READ_REGCNT_OFF] << 8);
reg_cnt |= (uint16_t)(frame_ptr[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 ((reg_cnt >= 1)
&& (reg_cnt < MB_PDU_FUNC_READ_REGCNT_MAX)) {
/* Set the current PDU data pointer to the beginning. */
frame_cur = &frame_ptr[MB_PDU_FUNC_OFF];
*len_buf = MB_PDU_FUNC_OFF;
/* First byte contains the function code. */
*frame_cur++ = MB_FUNC_READ_INPUT_REGISTER;
*len_buf += 1;
/* Second byte in the response contain the number of bytes. */
*frame_cur++ = (uint8_t)(reg_cnt * 2);
*len_buf += 1;
if (inst->rw_cbs.reg_input_cb) {
reg_status = inst->rw_cbs.reg_input_cb(inst, frame_cur, reg_addr, reg_cnt);
}
/* If an error occured convert it into a Modbus exception. */
if (reg_status != MB_ENOERR) {
status = mb_error_to_exception(reg_status);
} else {
*len_buf += reg_cnt * 2;
}
} else {
status = MB_EX_ILLEGAL_DATA_VALUE;
}
} else {
/* Can't be a valid read input register request because the length
* is incorrect. */
status = MB_EX_ILLEGAL_DATA_VALUE;
}
return status;
}
#endif