What is a watchdog timer and how is it used in telemetry equipment?

• A. It measures battery health.
• B. It increases data throughput.
• C. It encrypts communications.
• D. It resets the system if software hangs or fails to check in within a period.

Answer: (D)

A watchdog timer is a reliability feature that keeps telemetry systems from getting stuck if software stops responding. It works by requiring the running program to regularly reset or “kick” the timer; if the program hangs, crashes, or fails to check in within the pre-set period, the timer triggers a reset of the processor or a safe restart. This automatic recovery is essential in telemetry, where data must keep flowing from remote sensors or spacecraft and human intervention can be slow or impossible. By ensuring the system restarts and resumes normal operation after a fault, the watchdog minimizes downtime and maintains ongoing data transmission. The other functions—measuring battery health, increasing data throughput, or encrypting communications—aren’t roles of a watchdog timer.