The Simplex 4098-9794 is a modular TrueAlarm sounder base designed for use with compatible TrueAlarm photoelectric and heat sensor heads. It combines an audible notification appliance and an analog addressable sensor interface into a single ceiling- or wall-mounted device.

The base provides a built-in piezoelectric sounder rated at 88 dBA minimum at 10 feet, operating from 24 VDC or from a compatible Notification Appliance Circuit (NAC). When NAC powered, sounder operation can be synchronized (Temporal, March Time, etc.) by the NAC. The sounder can also be manually activated from the control panel.

TrueAlarm analog sensor information is digitally communicated to the fire alarm control panel via IDNet or MAPNET II communications. Address selection is base-mounted, allowing the programmed address to remain with the installed location even when the sensor head is removed for service.

The 4098-9794 is listed to UL 268 for smoke detection (with compatible sensor) and UL 464 as an audible notification appliance.