mirror of https://github.com/3cky/mbusd.git
105 lines
3.9 KiB
C
105 lines
3.9 KiB
C
/*
|
|
* OpenMODBUS/TCP to RS-232/485 MODBUS RTU gateway
|
|
*
|
|
* modbus.h - MODBUS protocol related procedures
|
|
*
|
|
* Copyright (c) 2002-2003, 2013, Victor Antonovich (v.antonovich@gmail.com)
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* - 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* ``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 REGENTS OR
|
|
* CONTRIBUTORS 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.
|
|
*
|
|
* $Id: modbus.h,v 1.3 2015/02/25 10:33:57 kapyar Exp $
|
|
*/
|
|
|
|
#ifndef _MODBUS_H
|
|
#define _MODBUS_H
|
|
|
|
#include "globals.h"
|
|
|
|
/*
|
|
* Macro for accessing data in MODBUS frame
|
|
*/
|
|
#define MB_FRAME(p, d) ( *(p + d) )
|
|
|
|
/*
|
|
* MODBUS frame lengths
|
|
*/
|
|
#define MB_EX_LEN 3
|
|
#define MB_MIN_LEN 4
|
|
#define MB_ERR_LEN 5
|
|
#define MB_MAX_LEN 256
|
|
|
|
/*
|
|
* Macros for word operations
|
|
*/
|
|
#define HIGH(w) ( (unsigned char)(((w) >> 8) & 0xff) )
|
|
#define LOW(w) ( (unsigned char)((w) & 0xff) )
|
|
#define WORD_WR_BE(p, w) do \
|
|
{ *(p) = (unsigned char)(((w) >> 8) & 0xff); \
|
|
*(p + 1) = (unsigned char)((w) & 0xff); } \
|
|
while (0);
|
|
#define WORD_RD_BE(p) ( (((unsigned short)*(p) << 8) & 0xff00) + \
|
|
(*(p + 1) & 0xff) )
|
|
#define WORD_WR_LE(p, w) do \
|
|
{ *(p) = (unsigned char)((w) & 0xff); \
|
|
*(p + 1) = (unsigned char)(((w) >> 8) & 0xff); } \
|
|
while (0);
|
|
#define WORD_RD_LE(p) ( (((unsigned short)*(p + 1) << 8) & 0xff00) + \
|
|
(*(p) & 0xff) )
|
|
|
|
/*
|
|
* MODBUS packet structure
|
|
*/
|
|
#define MB_TRANS_ID_H 0 /* transaction ID high byte */
|
|
#define MB_TRANS_ID_L 1 /* transaction ID low byte */
|
|
#define MB_PROTO_ID_H 2 /* protocol ID high byte */
|
|
#define MB_PROTO_ID_L 3 /* protocol ID low byte */
|
|
#define MB_LENGTH_H 4 /* length field high byte */
|
|
#define MB_LENGTH_L 5 /* length field low byte */
|
|
#define MB_UNIT_ID 6 /* unit identifier */
|
|
#define MB_FCODE 7 /* function code */
|
|
#define MB_DATA 8 /* MODBUS data */
|
|
#define MB_DATA_ADDR_H MB_DATA /* MODBUS data: address high byte */
|
|
#define MB_DATA_ADDR_L 9 /* MODBUS data: address low byte */
|
|
#define MB_DATA_NVAL_H 10 /* MODBUS data: number of values high byte */
|
|
#define MB_DATA_NVAL_L 11 /* MODBUS data: number of values low byte */
|
|
#define MB_DATA_NBYTES 12 /* MODBUS data: number of bytes to follow (fc 15,16) */
|
|
|
|
#define TTY_FCODE_IDX 1 /* The index of the function code in a RTU packet */
|
|
#define TTY_ERR_MASK 0x80 /* The MSB of the response function code indicates an error response */
|
|
|
|
/*
|
|
* Exception codes
|
|
*/
|
|
#define MB_EX_CRC 4
|
|
#define MB_EX_TIMEOUT 0x0B
|
|
|
|
/* Prototypes */
|
|
int modbus_crc_correct(unsigned char *frame, unsigned int len);
|
|
void modbus_crc_write(unsigned char *frame, unsigned int len);
|
|
void modbus_ex_write(unsigned char *packet, unsigned char code);
|
|
int modbus_check_header(unsigned char *packet);
|
|
|
|
|
|
#endif /* _MODBUS_H */
|