Clock network

Others provide SMPTE time code outputs, which are often used in television settings to synchronize the video from multiple sources.

Master Clocks often come equipped with programmable relay outputs to synchronize other devices such as lights, doors, etc.

A central clock system allows a television station's master control and production personnel to work within that schedule.

A clock network synchronized to the standard UTC time also allows different television facilities to coordinate their activities without complicated out-of-band signaling.

For example, the National Emergency Number Association issued directive NENA-04-002, offering standards in timekeeping for 911 dispatch centers throughout the United States.

Some master clocks were set up to control the frequency of a generating authority's mains output; others, in the UK, were arranged to synchronise themselves with the Greenwich Time Signal pips.

Diagram of electric time system used around 1910 to keep time in factories, schools, and other large institutions. The master clock , controlled by a temperature-compensated mercury pendulum, is wired to slave clocks throughout the building. In addition to wall clocks, it also controls time stamps that are used to stamp documents with the time, and a turret clock that is installed in a clock tower. The "program clock" is a timer that can be programmed with punched paper tape to ring bells or turn machines on and off at preprogrammed times.