I am using modbus4j 1.1 jar file for our project. I am often get the WaitingRoomException-No recipient was found waiting for response for key and sometimes RoomException: Waiting room too crowded. Already contains the key.

What is the reason I am getting this exception. Is there any way I can avoid getting this exception.
Why do we get this exception, Is there any scenario where we get them.

My device configuration is Modbus Ascii, baud Rate is 9600, I have set the default timeout(500 ms), default retries(2). I am currently polling every 5 sec.

Sometimes the exception occurs even without polling for data from the device.

Is there any relation between Modbus4j timeout and Waiting Room Exception? If I increase the timeout from 500ms to 2s, will it solve the issue.

(Exception occurs even in Modbus TCP devices)

Please kindly help me out in solving the waitingRoomException.