Lost communication - Solved!

[cjin]

Aprilaire plugin been running perfecy with HSPro for a long time, then all of a sudden HS is no longer communicating with any thermal stat:

In HS all thermal stats temp reading showing as 0 degree

On thermal stat, connection status showing disconnected (there is a X over the computer sign)

Thermal stat still controls actual HVAC unit fine using manual control

The protocol unit power is on and cable is intact.

Can anyone help pointing me to what I should check next?

[mwolfod]

I had the exact same thing happen to me about two years ago. For awhile, rebooting the Host PC and/or restarting HS PRO helped, but eventually I simply, consistently got no readings whatsoever from the Plug-in.


Multiple requests for help/guidance here yielded no responses, so I have moved on to an alternative tstat solution.

Sorry I couldn't be of help. I'm sure this is not what you wanted to hear.

I hope you have better success than I did.

[cjin]

Lost Communication (solved)

It turns out my 8811 protocol adaptor was dead. The technical support people at Aprilaire was very helpful. They told me to perform a loopback test on 8811 (connecting A- to B1, and A+ and B+, then connectect hyperterminal to 8811, type any letter and see if you see the same letter twice) which confirmed the problem with 8811. After replacing it, everything works fine.