modbus主站从站源码
时间: 2023-08-24 15:04:51 浏览: 46
以下是一个基于C语言的Modbus主站和从站的示例代码:
主站代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <modbus/modbus.h>
#define SERVER_ID 1
#define SERVER_ADDR "127.0.0.1"
#define SERVER_PORT 502
#define COIL_ADDR 0
#define COIL_NB 1
int main(int argc, char *argv[]) {
modbus_t *ctx;
uint8_t tab_bits[COIL_NB];
int rc;
ctx = modbus_new_tcp(SERVER_ADDR, SERVER_PORT);
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
exit(EXIT_FAILURE);
}
modbus_set_slave(ctx, SERVER_ID);
rc = modbus_read_bits(ctx, COIL_ADDR, COIL_NB, tab_bits);
if (rc != COIL_NB) {
fprintf(stderr, "Read failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
exit(EXIT_FAILURE);
}
printf("Value: %d\n", tab_bits[0]);
modbus_close(ctx);
modbus_free(ctx);
return 0;
}
```
从站代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <modbus/modbus.h>
#define SERVER_ID 1
#define SERVER_ADDR "127.0.0.1"
#define SERVER_PORT 502
#define COIL_ADDR 0
#define COIL_NB 1
int main(int argc, char *argv[]) {
modbus_t *ctx;
uint8_t tab_bits[COIL_NB];
int rc;
ctx = modbus_new_tcp(SERVER_ADDR, SERVER_PORT);
if (modbus_connect(ctx) == -1) {
fprintf(stderr, "Connection failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
exit(EXIT_FAILURE);
}
modbus_set_slave(ctx, SERVER_ID);
tab_bits[0] = 0xFF;
rc = modbus_write_bits(ctx, COIL_ADDR, COIL_NB, tab_bits);
if (rc != COIL_NB) {
fprintf(stderr, "Write failed: %s\n", modbus_strerror(errno));
modbus_free(ctx);
exit(EXIT_FAILURE);
}
printf("Value written\n");
modbus_close(ctx);
modbus_free(ctx);
return 0;
}
```
这两个代码示例可以用于在本地计算机上模拟一个Modbus TCP网络。在实际使用中,您需要根据您的实际情况进行修改,例如更改服务器ID、服务器地址、端口号和寄存器地址等。