I've got a strange scenario and I need input on thermostat wiring. I have 9 thermostats wired into an OmniPro II. They're wired in a "T" configuration with two inline to the controller and then branch two directions to all the others in parallel. Every one works and can send and receive from panel except the two thermostats at the extreme endpoints of the "T". These two units cannot send or receive data. We have swapped around thermostats so we have eliminated an internal thermostat issue. We have tested wiring and re-run wires and haven't found an issue with mis-wiring. The runs from each end of the "T" are about 80' and 160' respectively, and about 150' from the centre point back to the panel (about 300' and 130' panel to thermostat respectively) so they are quite long runs. The thermostats are older Omnistats (RC-80/90/100, etc).
I'm suspecting some sort of signal reflection at the termination points of the two end thermostats. Is there an end-of-line resistor I could plug in to suppress reflections and possibly get the last two thermostats to communicate reliably?
Thanks
I'm suspecting some sort of signal reflection at the termination points of the two end thermostats. Is there an end-of-line resistor I could plug in to suppress reflections and possibly get the last two thermostats to communicate reliably?
Thanks
