Simplex 4098-9756/4098-9714 Duct Detector

Recently I picked up a Simplex 4098-9756 Duct Detector Housing with a 4098-9714 Photoelectric Detector installed. I knew going in that this is an addressable unit, coming from a Simplex 4020 system, but it was free so I’m not concerned about actually having it function. However, I quickly noticed there are markings for direct 24V connections as well as remote indicator outputs.

I’m just curious if it is possible to wire up these connections in a way that would allow me to demonstrate the detector’s functionality, without having the SLC connected. I know next to nothing about these units in particular, so I’d rather hear some professional advice first before I try to connect anything.


This duct detector will do nothing without being connected to a MAPNET II or IDNet SLC. The -9714 is not a smoke detector, it is a smoke sensor. The difference is that a standard smoke detector makes the decision to go into alarm locally in the detector. In Truealarm sensors the decisions are made in the panel and transmitted to the sensor.

The -9714 sensor sends a number to the panel that represents the obscuration conditions in the chamber. The panel keeps a long term average for each sensor. A numerical offset is determined in the panel based on the programmed sensitivity level and the sensor’s long term average. If the immediate number is higher than that offset point the panel decides the sensor should be in alarm. The panel tells the sensor when to turn on the LED and the relay output.

The 24 volt connection is to power the relay control output. The -9714 sensor is powered by the SLC, not the 24 volt input. Without the SLC connected it will not flash. The sensor flashes when it is responding to a poll from the panel. The relay output are the terminals labeled ALM+ and ALM-. This is a supervised circuit that drives Air Products PAM-SD relays. The supervised relay can be mounted remote from the sensor housing to meet the requirement that the control be within 3 feet of the connection point.

That’s pretty much what I expected to hear. Oh well, no big loss.

Thank you for your help!

Yep. This unit is multi-protocol. Even though it came from a 4020 installation it will also work on an IDNet panel. If you find a sweet deal on a 4008 or 4010 it will work on those too. Or you could sell it to someone who does have a compatible panel.