基于C#实现基恩士PLC通信

一、通信协议选择

基恩士PLC支持多种通信协议，推荐优先采用以下两种方案：

1. TCP/IP Socket通信（通用性强，适用于以太网接口设备）
2. Modbus TCP协议（标准工业协议，兼容性强）

---

二、Socket通信实现（基于TCP/IP）

1. 基础通信类设计

using System.Net.Sockets;
using System.Text;public class KeyencePLCClient {private TcpClient _client;private NetworkStream _stream;private const int TimeoutMs = 5000;public bool Connect(string ip, int port = 8500) {try {_client = new TcpClient();_client.ReceiveTimeout = TimeoutMs;_client.SendTimeout = TimeoutMs;_client.Connect(ip, port);_stream = _client.GetStream();return true;} catch (SocketException ex) {LogError($"连接失败: {ex.Message}");return false;}}public byte[] SendCommand(byte[] command) {try {_stream.Write(command, 0, command.Length);_stream.Flush();byte[] buffer = new byte[1024];int bytesRead = _stream.Read(buffer, 0, buffer.Length);return buffer.Take(bytesRead).ToArray();} catch (Exception ex) {LogError($"通信异常: {ex.Message}");return null;}}public void Disconnect() {_stream?.Close();_client?.Close();}
}

2. 数据帧封装与解析

// 数据包结构示例（需根据具体PLC协议调整）
public class PlcDataFrame {public byte StartFlag { get; set; } = 0x02;public ushort Address { get; set; }public ushort Length { get; set; }public byte[] Data { get; set; }public byte Checksum { get; set; }public byte EndFlag { get; set; } = 0x03;// 计算LRC校验public byte CalculateChecksum() {byte sum = 0;foreach (var b in Data) sum += b;return (byte)(-sum & 0xFF);}// 打包数据帧public byte[] ToByteArray() {using (var ms = new MemoryStream()) {ms.WriteByte(StartFlag);ms.Write(BitConverter.GetBytes(Address), 0, 2);ms.Write(BitConverter.GetBytes(Length), 0, 2);ms.Write(Data, 0, Data.Length);ms.WriteByte(Checksum);ms.WriteByte(EndFlag);return ms.ToArray();}}
}

---

三、Modbus TCP协议实现

1. 功能码定义

public enum ModbusFunctionCode : byte {ReadCoils = 0x01,ReadDiscreteInputs = 0x02,ReadHoldingRegisters = 0x03,WriteSingleRegister = 0x06
}

2. 读写寄存器实现

public class ModbusHandler {private KeyencePLCClient _plcClient;public ModbusHandler(KeyencePLCClient client) => _plcClient = client;public ushort[] ReadHoldingRegisters(ushort startAddr, ushort count) {var frame = new PlcDataFrame {Address = startAddr,Length = count,Data = new byte[] { (byte)ModbusFunctionCode.ReadHoldingRegisters, 0x00 }};var response = _plcClient.SendCommand(frame.ToByteArray());if (response == null || response.Length < 5) throw new Exception("无效响应");ushort[] data = new ushort[count];for (int i = 0; i < count; i++) {data[i] = (ushort)(response[4 + i * 2] << 8 | response[5 + i * 2]);}return data;}public void WriteSingleRegister(ushort addr, ushort value) {byte[] data = { (byte)(value >> 8), (byte)value };var frame = new PlcDataFrame {Address = addr,Data = new byte[] { (byte)ModbusFunctionCode.WriteSingleRegister, 0x00, data[0], data[1] }};_plcClient.SendCommand(frame.ToByteArray());}
}

---

四、工业级应用优化策略

1. 异常处理机制

public class PlcExceptionHandler {public static void Handle(SocketException ex) {if (ex.SocketErrorCode == SocketError.ConnectionRefused) {// 重连逻辑Reconnect();} else if (ex.SocketErrorCode == SocketError.Timeout) {// 超时处理LogWarning("通信超时，检查网络状态");}}
}

2. 数据缓存与同步

public class PlcDataCache {private object _lock = new object();private Dictionary<string, object> _cache = new Dictionary<string, object>();public T GetData<T>(string key, Func<T> loadFunc) {lock (_lock) {if (!_cache.ContainsKey(key) || (DateTime.Now - _cache[key](@ref).LastUpdate).TotalSeconds > 5) {_cache[key](@ref)= new CacheItem(loadFunc(), DateTime.Now);}return (T)_cache[key](@ref).Value;}}private class CacheItem {public object Value { get; }public DateTime LastUpdate { get; }public CacheItem(object value, DateTime time) {Value = value;LastUpdate = time;}}
}

---

五、WinForms界面集成

1. 实时数据监控界面

<!-- 数据监控面板 -->
<GroupBox Text="PLC实时数据"><DataGridView x:Name="dgvData" AutoGenerateColumns="False"><Columns><DataGridViewTextBoxColumn HeaderText="地址" DataPropertyName="Address"/><DataGridViewTextBoxColumn HeaderText="值" DataPropertyName="Value"/></Columns></DataGridView><Button Content="刷新" Click="RefreshData"/>
</GroupBox>

2. 数据绑定示例

private void RefreshData() {var data = _plcClient.ReadHoldingRegisters(0x1000, 10);dgvData.DataSource = data.Select((v, i) => new {Address = 0x1000 + i,Value = v.ToString("X4")}).ToList();
}

参考代码 基恩士PLC 与C#通信(含c#和vb两个版本) www.youwenfan.com/contentcnh/49366.html

六、高级功能实现

1. 断线自动重连

public class AutoReconnectClient {private KeyencePLCClient _client;private string _ip;private int _port;private int _retryInterval = 5000;public AutoReconnectClient(string ip, int port) {_ip = ip;_port = port;Connect();}private void Connect() {Task.Run(async () => {while (true) {try {if (!_client.Connected) {_client.Connect(_ip, _port);LogInfo("重新连接成功");}await Task.Delay(1000);} catch {await Task.Delay(_retryInterval);}}});}
}

2. 数据加密传输

public class SecurePlcClient {private Aes _aes = Aes.Create();public byte[] Encrypt(byte[] data) {using (var encryptor = _aes.CreateEncryptor()) {return encryptor.TransformFinalBlock(data, 0, data.Length);}}public byte[] Decrypt(byte[] data) {using (var decryptor = _aes.CreateDecryptor()) {return decryptor.TransformFinalBlock(data, 0, data.Length);}}
}

---

七、调试与维护工具

1. 通信日志记录

public static class Logger {private static readonly string logPath = "plc_communication.log";public static void WriteLog(string message) {File.AppendAllText(logPath, $"{DateTime.Now:yyyy-MM-dd HH:mm:ss} - {message}{Environment.NewLine}");}
}

2. 数据包抓取工具

public class PacketSniffer {public static void Capture(byte[] rawData) {File.WriteAllBytes($"packet_{DateTime.Now:yyyyMMddHHmmss}.bin", rawData);}
}