Which statement correctly describes the relationship between an alarm and a signal in security systems?

• A. A signal is the notification that an event has occurred; an alarm is the event requiring action due to a trigger.
• B. An alarm is the event requiring action; a signal is the notification that an event has occurred, which may trigger an alarm.
• C. Alarm and signal are synonyms.
• D. A signal triggers the alarm; an alarm is the notification after action.

Answer: (B)

In security systems, information flow is about what happens first and what it prompts. A signal is the notification from a sensor that an event has occurred—data that travels to the control system. An alarm is the action or condition that requires a response, such as sounding sirens, alerting personnel, or initiating lockdown. The correct description captures that sequence: the signal announces the event, and that signal may trigger the alarm, which is the event requiring action. For example, a door contact detects opening and sends a signal to the panel; if the opening is deemed unauthorized, the system triggers the alarm. The other statements either treat alarm and signal as the same thing or reverse the relationship, which doesn’t reflect how information leads to a response in security setups.