lzthqx

I can confirm that there have been no power issues. The device is connected to a large regulated UPS. It's strange. I am able to connect to the PLM via a usb serial cable and operate the PLM from HomeAssistant directly, but no PLM seems to want to connect to the ISY.

Hi again, I am attaching the image as requested.

I purchased a brand new PLM today, hooked it up and followed the startup procedure. No connection. Any chance for an answer to my original question on how to test the ISY?Thanks, Robert

I have an isy99iPRO/ZW that no matter what, cannot connect to PLMs. I have gone through 2 PLMs so far replacing them for newer ones, only to have to do it again after a few months (I have 3 now). Silly me, I never checked the PLMs themselves, I just assumed they were faulty (because the ISY goes into safe mode). Frustrated, I installed 2 other smarthome products (HomeAssistant, and Homeseer). The PLMs work flawlessly with these systems! I have upgraded the firmware on the ISY to the latest. Switched cables (tried over 10 of different lengths and qualities), moved the PLM to another plug/location, tried all the startup sequence suggestions, reset the PLMs, checked the serial port pins, and updated the firmware. As I am now certain the issue lies with the ISY, how does one go about troubleshooting the serial port or device? Thanks..