Final answer:
The lamp test function is used to verify that all LEDs on the FACP are operational, which is crucial for maintaining the fire alarm system's reliability.
Step-by-step explanation:
The function used to check the status of the Light Emitting Diodes (LEDs) on the Fire Alarm Control Panel (FACP) is the lamp test function. To ensure the reliability and functionality of the fire alarm system, all the LEDs need to be operative.
During the lamp test, each LED on the FACP is illuminated to confirm that they are all in working condition. Any LED that does not light up during this test indicates a problem and requires further attention for repair or replacement.