Program Relay	Program Relay closes at the beginning of the program, stays latched for the duration of the program, and opens at the end of the program.
Break Relay	Break Relay closes at the beginning of the break, stays latched for the duration of the break, and opens at the end of the break.

We continue to receive many questions regarding our use of latched closures instead of momentary closures. The explanation is closely related to the explanation of relay mapping in that there are not enough relays for each audio service to have its own Program Start, Program Stop, Break Start, and Break Stop relay.

As such, to maximize efficiency of the limited number of relays, we use a single relay's status to indicate the status of the event, whether it be the Program relay or the Break relay. When either relay is on, the event is in progress, and when it is off, the event is not in progress. The closure's transistions indicate the start and stop of the event.

There are a variety of methods to translate the latched closures into the momentary closures that many automation systems require.

• A simple R-C (Resistor-Capacitor) network
• A dual "one-shot" interface utilizing the common 555 timer
• A logic converter (available from companies like Henry Engineering, Cross Technologies, Black Box)