public void open() throws ModbusException {

        // Start the listener if it isn' already running

        if (!isRunning) {
            try {
                listenerThread = new Thread(listener);
                listenerThread.start();
                isRunning = true;
            }
            catch (Exception x) {
                closeListener();
                throw new ModbusException(x.getMessage());
            }
        }
    }
public void open ( ) throws ModbusException { if ( ! isRunning ) { try { listenerThread = new Thread ( listener ) ; listenerThread . start ( ) ; isRunning = true ; } catch ( Exception x ) { closeListener ( ) ; throw new ModbusException ( x . getMessage ( ) ) ; } } }
Opens the listener to service requests

@throws ModbusException If we cannot listen