In such situations, the rover goes into what is known as the fault mode.

Depending on frequency, the beacon indicates normal operation, or one of seven fault modes.

Another control circuit employing fault mode logic gates was U.S. Pat.

In a fault mode, a method may return an invalid, incomplete or null response, or may throw an exception.

The next day, JPL received a beep from the rover, indicating that it was in fault mode.

They can also be set into predefined fault modes so that error-handling routines can be developed and reliably tested.

It can, using pre-programmed criteria to detect a fault, disable the system into "Hard Fault Mode" which can lower the vehicle to the suspension bump-stops and force the owner to limp to the dealership for inspection and repair.