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  • I start Mango with a Modbus IP data source created and get this error in the standar output:

    WARN 2010-04-16 10:51:48,781 (
    ce.scheduleTimeout:66) - Modbus ip Prueba: poll at 2010/04/16 10:51:48 aborted b
    ecause a previous poll started at 2010/04/16 10:51:38 is still running
    WARN 2010-04-16 10:51:54,031 (
    taSource.receivedException:226) - Modbus exception
    com.serotonin.messaging.WaitingRoomException: No recipient was found waiting for
    response for key com.serotonin.modbus4j.ip.IpWaitingRoomKey@7fa2
    at com.serotonin.messaging.WaitingRoom.response(
    WARN 2010-04-16 10:51:58,687 (
    ce.scheduleTimeout:66) - Modbus ip Prueba: poll at 2010/04/16 10:51:58 aborted b
    ecause a previous poll started at 2010/04/16 10:51:38 is still running

    What can be happening? There is now modbus server to connect.

  • 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.

  • I'm using TCP.

    How can I avoid this error?

  • Im not responding.

  • Solution: increase your timeout.

  • How much? I have my modbus server turn off.

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

  • 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.

    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(
    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}


    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();
        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,
            ModbusLocator locator2 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 3,
            ModbusLocator locator3 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 5,
            ModbusLocator locator4 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 7,
            ModbusLocator locator5 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 9,
            ModbusLocator locator6 = new ModbusLocator(slaveId, RegisterRange.HOLDING_REGISTER, 11,
            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);
            BatchResults<String> results = master.send(batchRead);
          finally {

    Thanking you in anticipation!

  • 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.

  • Luke, what happens if you increase the timeout?