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
|
/*
* Copyright © 2008-2014 Stéphane Raimbault <stephane.raimbault@gmail.com>
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdio.h>
#ifndef _MSC_VER
#include <unistd.h>
#endif
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <modbus.h>
#if defined(_WIN32)
#define close closesocket
#endif
enum {
TCP,
RTU
};
int main(int argc, char *argv[])
{
int s = -1;
modbus_t *ctx = NULL;
modbus_mapping_t *mb_mapping = NULL;
int rc;
int use_backend;
/* TCP */
if (argc > 1) {
if (strcmp(argv[1], "tcp") == 0) {
use_backend = TCP;
} else if (strcmp(argv[1], "rtu") == 0) {
use_backend = RTU;
} else {
printf("Usage:\n %s [tcp|rtu] - Modbus client to measure data bandwith\n\n", argv[0]);
exit(1);
}
} else {
/* By default */
use_backend = TCP;
}
if (use_backend == TCP) {
ctx = modbus_new_tcp("127.0.0.1", 1502);
s = modbus_tcp_listen(ctx, 1);
modbus_tcp_accept(ctx, &s);
} else {
ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
modbus_set_slave(ctx, 1);
modbus_connect(ctx);
}
mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,
MODBUS_MAX_READ_REGISTERS, 0);
if (mb_mapping == NULL) {
fprintf(stderr, "Failed to allocate the mapping: %s\n",
modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
for(;;) {
uint8_t query[MODBUS_TCP_MAX_ADU_LENGTH];
rc = modbus_receive(ctx, query);
if (rc > 0) {
modbus_reply(ctx, query, rc, mb_mapping);
} else if (rc == -1) {
/* Connection closed by the client or error */
break;
}
}
printf("Quit the loop: %s\n", modbus_strerror(errno));
modbus_mapping_free(mb_mapping);
if (s != -1) {
close(s);
}
/* For RTU, skipped by TCP (no TCP connect) */
modbus_close(ctx);
modbus_free(ctx);
return 0;
}
|
