在Java中如何实现Modbus TCP客户端和服务器

在Java中实现Modbus TCP客户端和服务器可以使用第三方库如jamod或者j2mod来实现。以下是一个简单的示例：

1. 使用jamod库实现Modbus TCP客户端：

import net.wimpi.modbus.Modbus; import net.wimpi.modbus.net.TCPMasterConnection; import net.wimpi.modbus.io.ModbusTCPTransaction; import net.wimpi.modbus.msg.ReadInputDiscretesRequest; import net.wimpi.modbus.msg.ReadInputDiscretesResponse; import net.wimpi.modbus.util.ModbusUtil;  public class ModbusTCPClient {     public static void main(String[] args) {         try {             TCPMasterConnection connection = new TCPMasterConnection("127.0.0.1");             connection.setPort(502);             connection.connect();              ReadInputDiscretesRequest request = new ReadInputDiscretesRequest(0, 10);             ModbusTCPTransaction transaction = new ModbusTCPTransaction(connection);             transaction.setRequest(request);             transaction.execute();              ReadInputDiscretesResponse response = (ReadInputDiscretesResponse) transaction.getResponse();             if (response != null) {                 for (int i = 0; i < response.getDiscretes().length; i++) {                     System.out.println("Coil " + i + " = " + response.getDiscretes()[i]);                 }             }              connection.close();         } catch (Exception e) {             e.printStackTrace();         }     } } 

2. 使用j2mod库实现Modbus TCP服务器：

import net.wimpi.modbus.procimg.SimpleDigitalIn; import net.wimpi.modbus.procimg.SimpleDigitalOut; import net.wimpi.modbus.procimg.SimpleProcessImage; import net.wimpi.modbus.ModbusCoupler; import net.wimpi.modbus.net.TCPListener;  public class ModbusTCPServer {     public static void main(String[] args) {         try {             ModbusCoupler.getReference().setProcessImage(new SimpleProcessImage());             ModbusCoupler.getReference().getProcessImage().addDigitalOut(new SimpleDigitalOut(true));             ModbusCoupler.getReference().getProcessImage().addDigitalIn(new SimpleDigitalIn(false));              TCPListener listener = new TCPListener(1);             listener.setPort(502);             listener.start();              System.out.println("Modbus TCP server running...");         } catch (Exception e) {             e.printStackTrace();         }     } } 

这些示例代码可以帮助你快速实现基本的Modbus TCP客户端和服务器功能。你也可以根据需要进一步扩展和定制功能。