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我正在使用jamod库在 Java 中开发 Modbus/TCP 主应用程序。在从我的从设备连续读取期间，连接被突然关闭。

我的代码：

import net.wimpi.modbus.io.ModbusTCPTransaction;
import net.wimpi.modbus.msg.ReadMultipleRegistersRequest;
import net.wimpi.modbus.msg.ReadMultipleRegistersResponse;
import net.wimpi.modbus.net.TCPMasterConnection;

public static void main(String[] args) throws Exception {
  TCPMasterConnection connection = new TCPMasterConnection(InetAddress.getByName("192.168.0.111"));
  connection.setPort(502);
  connection.connect();
  if (!connection.isConnected())
    return;

  System.out.println(readIntFromIntAddr(connection, 256));
  System.out.println(readIntFromIntAddr(connection, 256));
  System.out.println(readIntFromIntAddr(connection, 256));
  System.out.println(readIntFromIntAddr(connection, 256));
  System.out.println(readIntFromIntAddr(connection, 256));
  System.out.println(readIntFromIntAddr(connection, 256));
}

private static synchronized int readIntFromIntAddr(TCPMasterConnection connection, int address) throws Exception {
  ReadMultipleRegistersRequest Rreq = new ReadMultipleRegistersRequest(address, 1); // reading one register
  Rreq.setUnitID(1); // slaveAddress

  ModbusTCPTransaction trans = null;
  trans = new ModbusTCPTransaction(connection);
  trans.setRetries(3);
  trans.setReconnecting(true);
  trans.setRequest(Rreq);
  trans.execute();

  ReadMultipleRegistersResponse Rres = (ReadMultipleRegistersResponse) trans.getResponse();
  return Rres.getRegisterValue(0);
}

在第 6 次阅读期间抛出的错误

net.wimpi.modbus.ModbusIOException: Premature end of stream (Header truncated).
at net.wimpi.modbus.io.ModbusTCPTransport.readResponse(ModbusTCPTransport.java:190)
at net.wimpi.modbus.io.ModbusTCPTransaction.execute(ModbusTCPTransaction.java:192)
at cz.jlochman.marklar.drivers.connection.modbustcp.ModBusTcpConnection.readIntFromIntAddr(ModBusTcpConnection.java:280)
at cz.jlochman.marklar.drivers.connection.modbustcp.ModBusTcpConnection.main(ModBusTcpConnection.java:267)

出现此错误后，我无法恢复连接。我必须终止我的应用程序线程并再次启动应用程序。我找到了一些解决方法：Thread.sleep(500)在第 5 次阅读后添加会消除此异常。Thread.sleep(200)每次阅读后也有效。不幸的是，这些变通方法不足以满足我从从设备连续读取的需求。

有谁知道，会发生什么？

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0 回答 0