W601单片机 Modbus-RTU主站程序

以下是W601单片机Modbus-RTU主站程序的示例代码：

#include <reg52.h>
#include <intrins.h>

typedef unsigned char uint8_t;
typedef unsigned int uint16_t;

#define FOSC 24000000L
#define BAUD 9600
#define TIMER_1MS (65536 - FOSC / 1000)

sbit LED = P1^0;

#define SLAVE_ADDRESS 0x01

#define FUNCTION_READ_COILS 0x01
#define FUNCTION_READ_DISCRETE_INPUTS 0x02
#define FUNCTION_READ_HOLDING_REGISTERS 0x03
#define FUNCTION_READ_INPUT_REGISTERS 0x04
#define FUNCTION_WRITE_SINGLE_COIL 0x05
#define FUNCTION_WRITE_SINGLE_REGISTER 0x06
#define FUNCTION_WRITE_MULTIPLE_COILS 0x0F
#define FUNCTION_WRITE_MULTIPLE_REGISTERS 0x10

uint8_t g_receive_buffer[256];
uint8_t g_receive_count = 0;

void uart_init() {
    TMOD |= 0x20;
    TH1 = TL1 = -(FOSC / 12 / BAUD);
    TR1 = 1;
    SM0 = 0;
    SM1 = 1;
    REN = 1;
    ES = 1;
}

void timer_init() {
    TMOD |= 0x10;
    TH1 = TIMER_1MS >> 8;
    TL1 = TIMER_1MS & 0xFF;
    ET1 = 1;
    TR1 = 1;
}

void send_data(uint8_t *data, uint8_t length) {
    while (length--) {
        SBUF = *data++;
        while(!TI);
        TI = 0;
    }
}

uint16_t crc16(uint8_t *data, uint8_t length) {
    uint16_t crc = 0xFFFF;
    while (length--) {
        crc ^= *data++;
        for (uint8_t i = 0; i < 8; i++) {
            if (crc & 0x0001) {
                crc >>= 1;
                crc ^= 0xA001;
            } else {
                crc >>= 1;
            }
        }
    }
    return crc;
}

void on_receive() interrupt 4 {
    if (RI) {
        uint8_t byte = SBUF;
        RI = 0;
        g_receive_buffer[g_receive_count++] = byte;
    }
}

void on_timer1() interrupt 3 {
    static uint16_t counter = 0;
    TH1 = TIMER_1MS >> 8;
    TL1 = TIMER_1MS & 0xFF;
    if (++counter >= 100) {
        counter = 0;
        LED = !LED;
    }
}

void process_request() {
    uint16_t crc, address, function, start_address, quantity, value;
    if (g_receive_count >= 8) {
        address = g_receive_buffer[0];
        crc = crc16(g_receive_buffer, g_receive_count - 2);
        if (crc == ((uint16_t)g_receive_buffer[g_receive_count - 2] << 8 | g_receive_buffer[g_receive_count - 1])) {
            function = g_receive_buffer[1];
            start_address = ((uint16_t)g_receive_buffer[2] << 8 | g_receive_buffer[3]);
            quantity = ((uint16_t)g_receive_buffer[4] << 8 | g_receive_buffer[5]);
            value = ((uint16_t)g_receive_buffer[4] << 8 | g_receive_buffer[5]);
            if (address == SLAVE_ADDRESS) {
                switch (function) {
                    case FUNCTION_READ_COILS:
                        // TODO: Implement read coils
                        break;
                    case FUNCTION_READ_DISCRETE_INPUTS:
                        // TODO: Implement read discrete inputs
                        break;
                    case FUNCTION_READ_HOLDING_REGISTERS:
                        // TODO: Implement read holding registers
                        break;
                    case FUNCTION_READ_INPUT_REGISTERS:
                        // TODO: Implement read input registers
                        break;
                    case FUNCTION_WRITE_SINGLE_COIL:
                        // TODO: Implement write single coil
                        break;
                    case FUNCTION_WRITE_SINGLE_REGISTER:
                        // TODO: Implement write single register
                        break;
                    case FUNCTION_WRITE_MULTIPLE_COILS:
                        // TODO: Implement write multiple coils
                        break;
                    case FUNCTION_WRITE_MULTIPLE_REGISTERS:
                        // TODO: Implement write multiple registers
                        break;
                    default:
                        break;
                }
            }
        }
        g_receive_count = 0;
    }
}

void main() {
    uart_init();
    timer_init();
    while (1) {
        process_request();
    }
}

这是一个非常简单的示例程序，只包含了一些基本的函数和变量，实际应用中需要根据具体需求进行修改和完善。需要注意的是，这个程序只实现了Modbus-RTU主站的基本功能，具体的数据读取和写入需要根据具体设备协议进行实现。