Simplex 565-143 — TrueAlarm duct interface board, the version without relay.
A Simplex 4098 TrueAlarm duct sensor housing is built around two boards: an interface board carrying the field wiring terminals and the status LED, and a base board the smoke sensor plugs into. Simplex publishes each in a with-relay and a without-relay form, because duct housings are sold both as a plain addressable sampling unit and as a unit with a supervised output driving remote relays for fan shutdown and damper control.
- Simplex parts list entry: TrueAlarm Duct Interface Board, w/o relay, part 565-143
- With-relay version of the same board is 565-124
- Companion duct base board is 565-131 with relay, 565-144 without
- The housing status LED sits on the interface board and pulses to show panel polling
- 4098 TrueAlarm sensors report analog values over IDNet or MAPNET II two-wire communications
- In the housing range, 4098-9755 has no relay output; 4098-9756 adds a supervised relay output
This number is often ordered wrong. 565-124 is the same board with the relay and is not a substitute. 565-131 and 565-144 are the base board, a different assembly in the same housing. 562-962 is the older addressable duct housing detector board.
