单片机modbus实际项目源码
时间: 2023-09-18 22:03:08 浏览: 65
单片机Modbus实际项目的源码是根据具体应用需求而定的,以下是一个示例的单片机Modbus实际项目源码:
```c
#include <reg52.h>
sbit RS485 = P1^0; // 485收发控制脚
#define MODBUS_ADDRESS 0x01 // Modbus设备地址
#define MODBUS_BAUDRATE 9600 // Modbus通信波特率
unsigned char modbus_buff[8] = {0}; // Modbus数据缓冲区
// Modbus读寄存器数据处理函数
void read_registers(unsigned char reg_address, unsigned char reg_count)
{
unsigned char response[5] = {0};
unsigned int i = 0;
response[0] = MODBUS_ADDRESS;
response[1] = 0x03;
response[2] = reg_count;
// 读取寄存器数据并填充到响应帧中
for (i = 0; i < reg_count * 2; i += 2) {
response[i + 3] = read_register_data(reg_address + i);
response[i + 4] = read_register_data(reg_address + i + 1);
}
send_response(response, reg_count * 2 + 3);
}
// Modbus写寄存器数据处理函数
void write_registers(unsigned char reg_address, unsigned char reg_count)
{
unsigned char i = 0;
// 写入寄存器数据
for (i = 0; i < reg_count * 2; i += 2) {
write_register_data(reg_address + i, modbus_buff[i] * 256 + modbus_buff[i + 1]);
}
send_response(NULL, 0);
}
// 发送响应帧
void send_response(unsigned char *data, unsigned char count)
{
unsigned char i = 0;
// 设置为发送模式
RS485 = 1;
// 发送响应帧
for(i = 0; i <= count; i++) {
SBUF = data[i];
while(TI == 0);
TI = 0;
}
// 设置为接收模式
RS485 = 0;
}
// 主函数
void main()
{
// 初始化串口
PCON = 0x00;
SCON = 0x50;
TMOD = 0x20;
TH1 = TL1 = -(11059200UL/12/32/MODBUS_BAUDRATE);
TR1 = 1;
// 开启串口中断
EA = 1;
ES = 1;
// 初始化Modbus配置
// 主循环
while(1) {
}
}
// 串口中断服务函数
void UART_ISR() interrupt 4 using 1
{
unsigned char temp = 0;
if (RI) {
temp = SBUF;
RI = 0;
modbus_buff[0] = temp;
if (modbus_buff[0] == MODBUS_ADDRESS) {
// 解析Modbus请求帧
switch (modbus_buff[1]) {
case 0x03: // 读寄存器
read_registers(modbus_buff[2] * 256 + modbus_buff[3], modbus_buff[4] * 256 + modbus_buff[5]);
break;
case 0x10: // 写寄存器
write_registers(modbus_buff[2] * 256 + modbus_buff[3], modbus_buff[4] * 256 + modbus_buff[5]);
break;
default:
send_response(NULL, 0); // 非法请求,发送空响应帧
break;
}
}
}
}
```
以上是一个简单的单片机Modbus实际项目的源码示例,其中包含了读取和写入寄存器数据的处理函数,发送响应帧的函数和串口中断服务函数等。根据具体需求,可以在该源码的基础上进行修改和扩展。