Add a watchdog to detect loss of connection

[benhar-dev]

The current PLC code does not receive any information about the status of the xbox controller or Python application. If the controller were to be disconnected then the joystick and buttons would retain their last known values. This may not be ideal for your control code.

It would be best to implement a watchdog / cyclic toggle which reports the state of the xbox controller in the same way as EtherCAT reports WcState and InputToggle. This would allow you to take action on the last know values in a way which best suits the application.