The TC841E1019 Conventional Zone Interface module provides an interface between a zone of HONEYWELL® manufactured conventional type fire detection devices and an intelligent signalling loop. A single tri-colour LED indicates the status of the module. In normal conditions, the LED can be set by command from the control panel to blink green when the module is polled. In the case of a fire alarm on the conventional zone, the LED is switched on constant red by panel command. If a fault is detected on the conventional zone or the zone supply voltage drops below 18V, or a fault with the external power supply is signalled, the LED will blink yellow if enabled on the control panel. When a short circuit is detected on the loop to either side of the module, the LED is switched to show a constant yellow light.