Hieveryone, I have a Notifier SDX-551 (older CLIP based photoelectric smoke detector) on my 640 demo system that keeps giving me an INVREP (invalid reply) trouble, despite the fact that the detector is polling and appears to be communicating with the control panel. The only other device on this loop is an MMX-1 CLIP monitor module, which works just fine. The panel's protocol is set for CLIP
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