/
modbus-private.h
139 lines (121 loc) · 4.45 KB
/
modbus-private.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
* Copyright © 2010-2012 Stéphane Raimbault <stephane.raimbault@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _MODBUS_PRIVATE_H_
#define _MODBUS_PRIVATE_H_
#ifndef _MSC_VER
# include <stdint.h>
# include <sys/time.h>
#else
# include "stdint.h"
# include <time.h>
typedef int ssize_t;
#endif
#include <sys/types.h>
#include <config.h>
#include "modbus.h"
MODBUS_BEGIN_DECLS
/* It's not really the minimal length (the real one is report slave ID
* in RTU (4 bytes)) but it's a convenient size to use in RTU or TCP
* communications to read many values or write a single one.
* Maximum between :
* - HEADER_LENGTH_TCP (7) + function (1) + address (2) + number (2)
* - HEADER_LENGTH_RTU (1) + function (1) + address (2) + number (2) + CRC (2)
*/
#define _MIN_REQ_LENGTH 12
#define _REPORT_SLAVE_ID 180
#define _MODBUS_EXCEPTION_RSP_LENGTH 5
/* Timeouts in microsecond (0.5 s) */
#define _RESPONSE_TIMEOUT 500000
#define _BYTE_TIMEOUT 500000
/* Function codes */
#define _FC_READ_COILS 0x01
#define _FC_READ_DISCRETE_INPUTS 0x02
#define _FC_READ_HOLDING_REGISTERS 0x03
#define _FC_READ_INPUT_REGISTERS 0x04
#define _FC_WRITE_SINGLE_COIL 0x05
#define _FC_WRITE_SINGLE_REGISTER 0x06
#define _FC_READ_EXCEPTION_STATUS 0x07
#define _FC_WRITE_MULTIPLE_COILS 0x0F
#define _FC_WRITE_MULTIPLE_REGISTERS 0x10
#define _FC_REPORT_SLAVE_ID 0x11
#define _FC_WRITE_AND_READ_REGISTERS 0x17
typedef enum {
_MODBUS_BACKEND_TYPE_RTU=0,
_MODBUS_BACKEND_TYPE_TCP
} modbus_backend_type_t;
/*
* ---------- Request Indication ----------
* | Client | ---------------------->| Server |
* ---------- Confirmation Response ----------
*/
typedef enum {
/* Request message on the server side */
MSG_INDICATION,
/* Request message on the client side */
MSG_CONFIRMATION
} msg_type_t;
/* This structure reduces the number of params in functions and so
* optimizes the speed of execution (~ 37%). */
typedef struct _sft {
int slave;
int function;
int t_id;
} sft_t;
typedef struct _modbus_backend {
unsigned int backend_type;
unsigned int header_length;
unsigned int checksum_length;
unsigned int max_adu_length;
int (*set_slave) (modbus_t *ctx, int slave);
int (*build_request_basis) (modbus_t *ctx, int function, int addr,
int nb, uint8_t *req);
int (*build_response_basis) (sft_t *sft, uint8_t *rsp);
int (*prepare_response_tid) (const uint8_t *req, int *req_length);
int (*send_msg_pre) (uint8_t *req, int req_length);
ssize_t (*send) (modbus_t *ctx, const uint8_t *req, int req_length);
int (*receive) (modbus_t *ctx, uint8_t *req);
ssize_t (*recv) (modbus_t *ctx, uint8_t *rsp, int rsp_length);
int (*check_integrity) (modbus_t *ctx, uint8_t *msg,
const int msg_length);
int (*pre_check_confirmation) (modbus_t *ctx, const uint8_t *req,
const uint8_t *rsp, int rsp_length);
int (*connect) (modbus_t *ctx);
void (*close) (modbus_t *ctx);
int (*flush) (modbus_t *ctx);
int (*select) (modbus_t *ctx, fd_set *rset, struct timeval *tv, int msg_length);
} modbus_backend_t;
struct _modbus {
/* Slave address */
int slave;
/* Socket or file descriptor */
int s;
int debug;
int error_recovery;
struct timeval response_timeout;
struct timeval byte_timeout;
const modbus_backend_t *backend;
void *backend_data;
};
void _modbus_init_common(modbus_t *ctx);
void _error_print(modbus_t *ctx, const char *context);
int _modbus_receive_msg(modbus_t *ctx, uint8_t *msg, msg_type_t msg_type);
#ifndef HAVE_STRLCPY
size_t strlcpy(char *dest, const char *src, size_t dest_size);
#endif
MODBUS_END_DECLS
#endif /* _MODBUS_PRIVATE_H_ */