Recent content by Mookmook

Per your post I set on a mission to fix this and OMG I found the root cause. I attached two cat5 cables in the attic for the last keypad in J5, the return channel for Data A was much higher resistance and when attic gets hot, it acts like an open. It must be a bad crimp up there and I'm not...

RAL,    You are absolutely correct, even though it's in J7, resistance should be about half of what I was seeing. I'm a bonehead..2 x 120Ohm terminators...duh..  RS485 is versatile, but I think you figured out my problem; termination is the culprit. .    I took out the terminator on J7 and...

Thanks both of you! Can only make 1 post a day so will try to make it count. Haven't had a single expander trouble since the first post probably because ambient temps in PNW are 'normal' now.    I have a temp gun, but that circuit freeze is an awesome idea next time it happens. I redid the...

Hi everyone,    I've been a lurker on this forum for 15 years and finally created an account as I have never been so stuck before and would really appreciate any help. :)   I have an ELK M1 with 3 keypads, an input expander, wireless expander, output expander and an ethernet module. They all get...