In alarm cross zoning, what happens on the first zone violation?

• A. Nothing occurs on the local premise and the cross zoning timer commences.
• B. The panel transmits the alarm immediately.
• C. The system disarms.
• D. The local premises trigger the siren immediately.

Answer: (A)

In cross zoning, an alarm only fires when two separate zones are violated within a short window. This design helps prevent false alarms from a single sensor misread or user error.

On the first zone violation, nothing is transmitted and no local siren is sounded—the system simply starts the cross-zoning timer and records which zone was triggered. It’s waiting to see if a second, different zone is violated before it declares an alarm.

If a second zone is violated within that timer window, the system proceeds to escalate: it will typically transmit the alarm to the monitoring station and activate the local audible alert, confirming a real intrusion. If no second violation occurs in time, the timer expires and the event is discarded.

So the correct idea is that the first violation initiates the cross-zoning timer and does not yet trigger an alarm or local alert.