What is the purpose of audible and visual signal devices in an emergency system?

The purpose of audible and visual signal devices in an emergency system is to notify individuals about critical conditions, including the battery carrying load and identifying failures. These devices are designed to ensure that residents and occupants are aware of any limitations or issues within the emergency system, particularly when power outages or system failures occur.

By utilizing audible alarms and visual indicators, the emergency system can effectively communicate the status of critical components. This is vital for safety, as it allows individuals to take appropriate action in the event of an emergency, such as evacuating a structure or seeking assistance.

In contrast, the other options do not align with the primary function of these signal devices. Indicating that the battery charger is functioning or notifying about scheduled maintenance are not critical for immediate safety, nor do they relate to the operational integrity of emergency systems. Additionally, informing about the normal operation of the lighting system is unrelated to the emergency response capabilities that audible and visual signals provide.