kidde smoke relay with simon always in tamper state

I have a Simon Xt panel that is connected to Suretydiy/alarm.com. I want my hard-wired smoke detectors (nine kidde p12040 photoelectric alarms) to be monitored by my simon xt panel / alarm.com.

I read the following two articles which game me hope:
https://help.brinkshome.com/hc/en-us/community/posts/217926087-How-to-integrate-existing-interconnected-wired-fire-alarm-to-GE-Simon-XT
as well as
https://help.brinkshome.com/hc/en-us/articles/225662007

I purchased these 3 items:
kidde interconnect smoke relay module sm120x
interlogix nx-650n crystal door/window sensor
48 kohm resistor

I connected the kidde sm120x relay successfully using the blue and yellow wires from the relay module to the hard-wired terminals on the interlogix sensor (someone in article 1 pointed out that is the proper choice for a normally closed contact). I also removed the jumper from the interlogix sensor to set it to manual wired input.

The interlogix sensor was added successfully to the simon xt panel, and placed in the same group (for me that is group 26) as pre-existing <wireless> smoke alarms.

Good: When testing the kidde smoke detector, the ximon xt panel is triggered by the simon interlogix sensor. A smoke/fire alarm is reported and the ximon correctly sends the event to alarm.com.

Bad: The interlogix sensor is in a TAMPER state whenever the smoke alarm is not triggered/active. During a smoke alarm event from the sm120x, Alarm.com sees an “end of tamper”. Then when the smoke alarm is finished (when I stop pressing the test button on one of the hardwired smoke alarms), I disarm the Simon panel to end the smoke alarm state. At the moment I disarm the panel, the interlogix sensor GOES BACK TO A TAMPER STATE.

To recap, hard wired sensors are triggering panel as desired via the interlogix sensor. But the tamper state of the interlogix sensor is ACTIVE during normal state (no smoke alarm). The tamper state ends only temporarily, during the smoke alarm event. Consequently, when I try to arm the panel, I must endure Siri-like voice telling me that the new Interlogix sensor is in a tamper state. Only when an active smoke alarm is occuring via SM120x/interlogix does the tamper state end. It (the tamper state) resumes as soon as the event is over.

I hope someone can tell me what I did wrong or if there is any hope with this configuration. Thanks in advance!

On the whole I would recommend against this, as it pertains to fire protection, and it is not a UL listed solution for such an application.

You would be better off using the Interlogix Firefighter SLX-AD-T3 audio detector to monitor all interconnected smoke detectors with one device, it is intended and UL listed for fire protection.

kidde interconnect smoke relay module sm120x interlogix nx-650n crystal door/window sensor 48 kohm resistor

The nx-650n requires a 4.7 kohm resistor. 48 kohm is going to cause problems. Is that a typo or is it a 48 kohm resistor?

Tamper is reported due to either the sensor cover being removed and a tamper switch opening, or pertaining to wired circuits, when the resistance value is outside of the expected bounds.

That was a typo. Should’ve read 47 ohm.

I’m going to cut my losses and take your advice.

Thanks Jason.