C# modbus ascii通讯示例

在C#中，Modbus ASCII通信通常用于简单的串行通信，它基于ASCII字符编码来传输数据。以下是一个简化的C# Modbus ASCII通信示例，使用了`System.IO.Ports.SerialPort`类：

using System;
using System.IO.Ports;

class Program
{
    static void Main(string[] args)
    {
        // 创建SerialPort实例
        SerialPort port = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
        
        try
        {
            // 打开串口
            port.Open();

            // 发送请求
            string request = "03 00 00"; // Function Code (FC) 3 (Read Holding Registers), Start Address 0, Number of Registers 1
            byte[] bytesToWrite = ASCIIEncoding.ASCII.GetBytes(request);
            port.Write(bytesToWrite);

            // 接收响应
            byte[] bytesReceived = new byte[1];
            port.ReadTimeout = 500; // 设置读取超时时间
            if (port.BytesToRead > 0)
            {
                port.Read(bytesReceived, 0, 1);
                Console.WriteLine($"Response: {BitConverter.ToString(bytesReceived)}");
            }
            else
            {
                Console.WriteLine("No response received.");
            }

            // 关闭串口
            port.Close();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error occurred: {ex.Message}");
        }
    }
}