Error while polling

[mlohbihler]

I take it you're using UDP. Some background...

Request messages are sent, and then the thread "sits in the waiting room" for the response to come back. After a timeout the thread leaves the waiting room, shrugs its shoulders, and says that it didn't get a response.

Later, a response is received, but by that time "no recipient was found waiting for response".

Solution: increase your timeout.

[jjconti]

I'm using TCP.

How can I avoid this error?

[jjconti]

Im not responding.

[mlohbihler]

Solution: increase your timeout.

[jjconti]

How much? I have my modbus server turn off.

[mlohbihler]

As much as needed to make the message go away. Seriously, i can't be more specific than that.

[luke]

hi,

I have almost the same problem with the WaitingRoomException.
I set the timeout to different values with the same result, but the message
is received anyways.

output:
request:
00 00 00 00 00 06 03 03 00 01 00 0C ............

com.serotonin.messaging.WaitingRoomException: No recipient was found waiting for response for key com.serotonin.modbus4j.ip.xa.XaWaitingRoomKey@8008
at com.serotonin.messaging.WaitingRoom.response(WaitingRoom.java:69)
at com.serotonin.messaging.MessageControl.data(MessageControl.java:153)
at com.serotonin.messaging.InputStreamListener.run(InputStreamListener.java:76)
at java.lang.Thread.run(Thread.java:595)
response:
00 00 00 00 00 1B 03 03 18 43 67 12 25 00 00 00 .........Cg.%...
00 00 00 00 00 43 67 12 25 00 00 00 00 43 67 12 .....Cg.%....Cg.
25 %

{voltage 1=231.07088, voltage 6=231.07088, voltage 4=231.07088, voltage 3=0.0, voltage 2=0.0, voltage 5=0.0}

Source:

package test.sim;

import com.serotonin.modbus4j.BatchRead;
import com.serotonin.modbus4j.BatchResults;
import com.serotonin.modbus4j.ModbusFactory;
import com.serotonin.modbus4j.ModbusLocator;
import com.serotonin.modbus4j.ModbusMaster;
import com.serotonin.modbus4j.code.DataType;
import com.serotonin.modbus4j.code.RegisterRange;
import com.serotonin.modbus4j.ip.IpParameters;
 
public class BatchTest
{
  public static void main(String[] args) throws Exception {
    IpParameters tcpParameters = new IpParameters();
    tcpParameters.setHost("10.17.175.43");

    ModbusFactory modbusFactory = new ModbusFactory();
    ModbusMaster master = modbusFactory.createTcpMaster(tcpParameters, true);

//    master.setTimeout(5000);

    for(int i = 0; i < 50; i++) {

      try {
        BatchRead<String> batchRead = new BatchRead<String>();
        int slaveId = 3;

        ModbusLocator locator = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 1,
          DataType.FOUR_BYTE_FLOAT);

        ModbusLocator locator2 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 3,
          DataType.FOUR_BYTE_FLOAT);

        ModbusLocator locator3 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 5,
          DataType.FOUR_BYTE_FLOAT);

        ModbusLocator locator4 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 7,
          DataType.FOUR_BYTE_FLOAT);

        ModbusLocator locator5 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 9,
          DataType.FOUR_BYTE_FLOAT);

        ModbusLocator locator6 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 11,
          DataType.FOUR_BYTE_FLOAT);

        batchRead.addLocator("voltage 1", locator);
        batchRead.addLocator("voltage 2", locator2);
        batchRead.addLocator("voltage 3", locator3);
        batchRead.addLocator("voltage 4", locator4);
        batchRead.addLocator("voltage 5", locator5);
        batchRead.addLocator("voltage 6", locator6);

        master.init();

        BatchResults<String> results = master.send(batchRead);

        System.err.println(results);
      }
      finally {
        master.destroy();
      }
    }
  }
}

Thanking you in anticipation!

[mlohbihler]

How much? I have my modbus server turn off.

I guess i didn't read the entire question. If your modbus server is turned off, shouldn't you expect an error? There is obviously no appropriate timeout for equipment that will never answer.

[mlohbihler]

Luke, what happens if you increase the timeout?