GE Concord 4 System Test 44 - System Sensor i3 2WTA-B & RRS-MOD

I thought it would be interesting to post a video of sounder-smokes on here. Not too many systems on YouTube with them.https://www.youtube.com/watch?v=5Pn92lA9lgM
This is a partial system test of my GE Concord 4 system. In this video, I demonstrate my brand new System Sensor RRS-MOD (polarity-reversal and synchronization relay module), and 4 System Sensor i3 2WTA-Bs. The 2WTA-B is a 2-wire photoelectric smoke detector with two fixed 135° thermal sensors and a built-in sounder. They all sound in sync when the panel alarms with help from the RRS-MOD.

While messing around, I’ve “reverse-engineered” the RRS-MOD. It reverses the polarity in code-3 in alarm, and when the alarm stops, it switches back to normal polarity, and all sounder-smokes go into selective-silence (if it was in alarm) or back to normal operation (if it was not in alarm).