Can't get Aprilaire 8811 protocol adapter talking

[asteinmetz]

Excuse this duplicate post as this is also part of a message in my HA progress thread.

I have six Aprilaire 8870 stats. All work fine on a standalone basis. So now I have to get them talking to the Elk (and whatever future HA controller I use). I have the distribution panel and protocol adapter wired in. The protocol adapter converts the RS485 to RS232 that the elk serial interface uses. I hooked them up to the elk per the elk instructions and got nuthin'. So I take a step back and use the Aprilaire hookup instructions which tell you to get a dumb terminal talking to the 'stats before hooking it up further. I plug the RS232 cable from the adapter into my trusty Linux box and fire up gtkterm. I use the default protocol spec of 8N1, Echo on, at 9600 BAUD (remember when that was a FAST modem?). Nuthin'. The docs say I should see the RS232 RX and RS485 TX lights flash when I type in the terminal window. Nope. There is one tantalizing clue. When I send a <BREAK> to the adapter the appropriate lights do flash, so the adapter isn't quite deaf. The Aprilaire docs say "consult a computer professional" if things don't go well. The "Geek Squad" could solve this, I'm sure. Thanks.

 

[gacevich]

art, i currently have 4 t-stats connected to the 8818 distro panel and then to a 8811 protocol adapter. Heck, i've even got the 6404 damper control panel woven in. it sounds like you may be having some of the same frustrations i had when originally getting the system to work. i don't have a silver bullet answer to your question, but there are two things that i kept falling back on in order to solve my problems: recheck wiring and call aprilaire tech support.

if you search the forum you will see over and over again that aprilaire equipment is very sensitive to the quality of the contacts/connections made. i found that starting with one t-stat and reconfirming the wiring and connections would allow me to get one running then build upon that. when all else failed, i found the tech support at aprilaire to be very friendly and helpful.

that being said, i did have one 8811 go bad on me. possible power surge (lightinging?). replaced it and all is well. when testing connectivity with the elk it was easiest for me to go to an elk keypad and look to see if it would display the t-stat's temperature. temp display = good connection.

good luck.