Elk M1 not communicating with TStat

I am having a difficult time getting my M1 to see my newly installed RCS thermostat. Here are the symptoms:
  • The tstat has been installed correctly and is communicating properly with the HVAC system
  • I have 2 M1 serial expanders (one for lighting (addr 3) and one for tstat (addr 4)) connected to my M1 on the databus expander.
  • These M1xsp's have been enrolled.
  • In Elk RP, both the lighting and thermostat serial port expanders are visible, with firmware 1.0.16 loaded.
  • In Elk RP, Tstat 01 is labeled “Living Roomâ€
  • Light on tstat M1xsp is a series of slow blinks, then solid light with fast flickers, then slow blink.
  • RCS tstat Address is set to 01.
  • In M1 web interface: Living Room tstat has a “unit not responding†message
  • On keypad, under Thermostats, I see: “Living room T01:Not Enabledâ€
  • I have triple-checked all connections and jumper settings.
Any ideas how to troubleshoot this?

I called Jim and he got me on the right track. Thanks Automated Outlet!!

For others ... the trick was to set the the tstat M1Xsp address to 1, and the lighting M1xsp address to 2. (In other words, don't skip any databus expander addresses and don't count the keypads in the numbering sequence.) After re-addressing, re-enroll the serial expanders. All is well.

Thanks again.