Reference signal synchronized to clock signal

A system comprising a clock board comprising a clock generator, a first board comprising an indicator and coupled to said clock board. The clock generator generates a clock signal, and the first board is configured to receive said clock signal. The first board further comprises a clock synchronizing unit that synchronizes a reference signal with said clock signal and generates a blink cadence signal based on said reference signal. The blink cadence signal is configured to drive the indicator of said first board. A failure by said first board to receive said clock signal causes the clock synchronizing unit of said first board to maintain the reference signal and generate said blink cadence signal based on said reference signal.