1. Show Control. A process of communication between two pieces of equipment. One will ask the other "Are you okay?" If the respondee does not reply "I'm okay" within a set period of time, the asking device sends an error message or other alert signal up to and including stopping the show. Also known as a "heartbeat" detector. 2. A watchdog timer is a hardware reset function that must be periodically disabled by a healthy software program. Thus, if the software is crashed, it does not execute the disable, and the watchdog timer hits the reset line and restarts the device.