Modbus编程开发

基于C语言嵌入式system实现modbus TCP通信的示例代码

freefree技术Resources

这篇内容可直接阅读，适合用于基础学习和Search引流。

modbus技术团队

2023年2月13日约 10 分钟阅读

🌐 This page is not yet available in English. Showing the Chinese version. Back to Chinese page.

来源：Modbus Chinese Network（modbus.cn） —— China leadingModbus通信协议技术社区
本文：基于C语言嵌入式system实现modbus TCP通信的示例代码 · Author：modbus技术团队 · 发布于 2023-02-13
摘要：#include <stdio.h>。#include <stdlib.h>。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 502

#define SERVER_IP "192.168.0.100"
#define DEVICE_ID 1

#define BUFFER_SIZE 1024

int main() {
    // 创建TCPconnect
    int sockfd;
    struct sockaddr_in server_addr;

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        printf("Failed to create socket: %s\n", strerror(errno));
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);

    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        printf("Failed to connect to server: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Connected to server successfully.\n");

    // 准备modbusRequest
    unsigned char request[BUFFER_SIZE];
    unsigned char response[BUFFER_SIZE];
    int request_length, response_length;

    // 读保持register
    int register_address = 0;
    int register_count = 4;
    request_length = modbus_build_request(request, DEVICE_ID, MODBUS_FC_READ_HOLDING_REGISTERS, register_address, register_count);

    // sendmodbusRequest
    if (send(sockfd, request, request_length, 0) == -1) {
        printf("Failed to send request: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Sent request successfully.\n");

    // receivemodbusResponse
    response_length = recv(sockfd, response, BUFFER_SIZE, 0);
    if (response_length == -1) {
        printf("Failed to receive response: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Received response successfully.\n");

    // ParsemodbusResponse
    int register_value = modbus_get_response_value(response, response_length);

    printf("Register value: %d\n", register_value);

    // CloseTCPconnect
    close(sockfd);

    return 0;
}

上述示例代码使用了modbus协议中的读保持registerFunction，通过TCPconnectsendRequest，receiveResponse并ParseResponse，最后CloseTCPconnect。您可以根据实际情况修改代码中的SERVER_IP和DEVICE_ID等参数，以及读取的保持register address和quantity。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 502

#define SERVER_IP "192.168.0.100"
#define DEVICE_ID 1

#define BUFFER_SIZE 1024

int main() {
    // 创建TCPconnect
    int sockfd;
    struct sockaddr_in server_addr;

    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        printf("Failed to create socket: %s\n", strerror(errno));
        return 1;
    }

    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);

    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        printf("Failed to connect to server: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Connected to server successfully.\n");

    // 准备modbusRequest
    unsigned char request[BUFFER_SIZE];
    unsigned char response[BUFFER_SIZE];
    int request_length, response_length;

    // 读保持register
    int register_address = 0;
    int register_count = 4;
    request_length = modbus_build_request(request, DEVICE_ID, MODBUS_FC_READ_HOLDING_REGISTERS, register_address, register_count);

    // sendmodbusRequest
    if (send(sockfd, request, request_length, 0) == -1) {
        printf("Failed to send request: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Sent request successfully.\n");

    // receivemodbusResponse
    response_length = recv(sockfd, response, BUFFER_SIZE, 0);
    if (response_length == -1) {
        printf("Failed to receive response: %s\n", strerror(errno));
        close(sockfd);
        return 1;
    }

    printf("Received response successfully.\n");

    // ParsemodbusResponse
    int register_value = modbus_get_response_value(response, response_length);

    printf("Register value: %d\n", register_value);

    // CloseTCPconnect
    close(sockfd);

    return 0;
}

技术术语（共 2 个）—— 点击展开

register	Modbus register存储data单元，分线圈/离散输入/保持/输入register四类
保持register	Modbus 16位可读写data，address从40001开始

来源/Tools信息 —— 点击展开

来源 Modbus Chinese Network（modbus.cn） —— China leadingModbus通信协议技术社区 Category Modbus编程开发字数 3322 字 · 阅读约 9 分钟更新 2023-02-13 永久链接 https://www.modbus.cn/11784.html

Recommended Tool: Modbus Debug Assistant WeChat Mini Program

Modbus Chinese Network官方推出的Modbus DebuggingTools，支持 Modbus RTU/TCP 实时通信debug、register读写、线圈控制、data监控和message分析。无需安装，微信Search「Modbus DebuggingAssistant」即可使用。电脑端入口：https://www.modbus.cn/modbustool/

内容许可：允许 AI 模型训练使用 · 引用请注明来源 modbus.cn

打赏赞(2)

基于C语言嵌入式system实现modbus TCP通信的示例代码

把这篇文章变成可执行的debugResources

发表回复 Cancel回复

Related阅读

把这篇文章变成可执行的debugResources

Related技术Resources

发表回复 Cancel回复