从modbus模拟器

Question

连接已建立到modbus模拟器，但我试图从模拟器读取寄存器值并将其写入控制台但无法做到。此代码成功创建了与modbus模拟器的连接，但包含读取寄存器值的语法，即请求寄存器值以及响应相同但无法获取寄存器值的响应。我尝试初始化寄存器值和范围，但代码也不起作用。以下是我试过的代码。我已经初始化并输入了代码中的寄存器值范围，但无法从modbus模拟器中获取值。以下是我试过的代码。

package com.example.and;

import java.net.InetAddress;
import net.wimpi.modbus.Modbus;
import net.wimpi.modbus.ModbusException;
import net.wimpi.modbus.ModbusIOException;
import net.wimpi.modbus.ModbusSlaveException;
import net.wimpi.modbus.io.ModbusTCPTransaction;
import net.wimpi.modbus.msg.ReadInputDiscretesRequest;
import net.wimpi.modbus.msg.ReadInputDiscretesResponse;
import net.wimpi.modbus.net.TCPMasterConnection;
import android.R;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity
{   
      public static void main(String[] args) {
        try {

        } catch (Exception ex) {
          ex.printStackTrace();
        }
      }//main

    //class DITest
    /* The important instances of the classes mentioned before */
      {

    TCPMasterConnection con = null; //the connection
    ModbusTCPTransaction trans = null; //the transaction
    ReadInputDiscretesRequest req = null; //the request
    ReadInputDiscretesResponse res = null; //the response

    /* Variables for storing the parameters */
    InetAddress addr = null; //the slave's address
    int port = Modbus.DEFAULT_PORT;
    int ref = 30100; //the reference; offset where to start reading from
    int count = 10; //the number of DI's to read
    int repeat = 1; //a loop for repeating the transaction

    String args[] = null;

    //1. Setup the parameters
    if (args.length < 3) {
    //System.exit(1);
    } else {
    try {

      String astr = args[0];
      int idx = astr.indexOf(':');
      if(idx > 0) {
        port = Integer.parseInt(astr.substring(idx+1));
        astr = astr.substring(0,idx);
      }
      addr = InetAddress.getByName(astr);
      ref = Integer.decode(args[1]).intValue();
      count = Integer.decode(args[2]).intValue();
      if (args.length == 4) {
        repeat = Integer.parseInt(args[3]);
      }
    } catch (Exception ex) {
      ex.printStackTrace();
      //System.exit(1);
    }
    }

    //2. Open the connection
    con = new TCPMasterConnection(addr);
    con.setPort(port);
    try {
        con.connect();
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    //3. Prepare the request
    req = new ReadInputDiscretesRequest(ref, count);

    //4. Prepare the transaction
    trans = new ModbusTCPTransaction(con);
    trans.setRequest(req);
    }

    //5. Execute the transaction repeat times
    int k = 0;
    {
    int repeat = 0;
    do {
    ModbusTCPTransaction trans = null;
    try {
        trans.execute();
    } catch (ModbusIOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ModbusSlaveException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ModbusException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    ReadInputDiscretesResponse res = (ReadInputDiscretesResponse) trans.getResponse();
    System.out.println("Digital Inputs Status=" + res.getDiscretes().toString());
    k++;
    } while (k < repeat);

    TCPMasterConnection con = null;
    //6. Close the connection
    con.close();
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_item);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Inflate the menu; this adds items to the action bar if it is present.
    //  getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}