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在C#中进行Modbus TCP的异步通信通常可以通过使用TcpClient
类和NetworkStream
类来实现。下面是一个简单的示例代码,展示了如何使用这两个类来实现Modbus TCP的异步通信:
using System; using System.Net; using System.Net.Sockets; using System.Threading.Tasks; class ModbusTcpClient { private TcpClient client; private NetworkStream stream; public ModbusTcpClient(string ipAddress, int port) { client = new TcpClient(); client.Connect(IPAddress.Parse(ipAddress), port); stream = client.GetStream(); } public async Task<byte[]> ReadHoldingRegistersAsync(byte slaveId, ushort startAddress, ushort quantity) { byte[] data = { slaveId, 0x03, (byte)(startAddress >> 8), (byte)startAddress, (byte)(quantity >> 8), (byte)quantity }; await stream.WriteAsync(data, 0, data.Length); byte[] response = new byte[256]; int bytesRead = await stream.ReadAsync(response, 0, response.Length); byte[] result = new byte[bytesRead]; Array.Copy(response, result, bytesRead); return result; } public void Close() { stream.Close(); client.Close(); } } class Program { static async Task Main() { ModbusTcpClient modbusClient = new ModbusTcpClient("192.168.1.1", 502); byte[] response = await modbusClient.ReadHoldingRegistersAsync(1, 0, 10); Console.WriteLine(BitConverter.ToString(response)); modbusClient.Close(); } }
在上面的示例中,我们创建了一个ModbusTcpClient
类来处理Modbus TCP通信。在ReadHoldingRegistersAsync
方法中,我们向服务器发送了读保持寄存器的命令,然后异步读取服务器的响应。在Main
方法中,我们创建了一个ModbusTcpClient
实例,并异步调用ReadHoldingRegistersAsync
方法来读取保持寄存器的值。最后,我们关闭了ModbusTcpClient
实例。
请注意,上面的示例代码只是一个简单的示例,实际应用中可能需要根据Modbus协议的具体要求进行更复杂的处理。