How to Count?

[dutchyn]

I have ClimateMaster geothermal units containing their CXM internal controller. ClimateMaster uses the alarm line to indicate fault codes as described in the attached table:


ClimateMaster offers thermostats which can decode these fault codes, but cannot communicate with home automation. I've chosen to install an HAI RC-2000 instead, and I'd like to recover the fault code monitoring. I have an Elk M1G input attached to a monitoring relay on the alarm line. The question is can I get an Elk M1G to recognize the 1/3 second flashes? If that's possible, I believe I can devote an Elk register to count the flashes, yielding the fault code. Then, after the pause following the code, I can emit a specific error voice message and reset the register.

Would using the fast-loop mode of the on-board input lines give me sub-second resolution of the on/off flash events, via WHENEVER ALARM[Zn3] BECOMES ... kinds of programming?

Failing that, I can build a separate discrete logic circuit that can count and encode the fault code into four input lines. But as a software guy, programming is easier and more configurable.

 

[dutchyn]

Almost a hundred views ... no replies, including from the Elk guys. It seems it's interesting, but no-one knows the answers. If I figure it out, I'll post.

 

[electron]

I think 1/3th of a second is doable, as long as you globals are configured correctly (Zones tab). Only one way to find out Worst case, you have to use a hardware counter (or build a cheap Arduino based interface).

 

[dutchyn]

The fastloop trick worked for me. The rules weren't too hairy; I needed two counters:

1. the first counts the pulses, adding one each pulse
2. the second counter is set on the first alarm pulse to be 8 seconds, and counts down to a readout and reset of the alarm code

I figured this out a long time ago, but it didn't matter much because no-one seemed interested in RC-2000 thermostats for ClimateMaster. Now, NextEnergy.ca, the national dealer/installer for ClimateMaster in Canada, has introduced an NE-32-2000 thermostat, a repackaged RC-2000. Anyone who wants to connect it to home automation will likely want the same automation features I developed.