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Aprilaire 8800...
itismyworld
Junior Member
Hello all, hopefully someone has an answer for this....don't want to be blowing stuff up.
First, I have acquired a brand new Aprilaire 8800 TStat.
Can an 8800 (since my house only has one stat) be wired directly to a processor via RS-485? If so, what would that connection be?
If I do need a protocol adapter, will the older style red 8811 style work with the 8800? I can get a deal on one of those if needed.
Thanks to anyone that can help!!!!!!
First, I have acquired a brand new Aprilaire 8800 TStat.
Can an 8800 (since my house only has one stat) be wired directly to a processor via RS-485? If so, what would that connection be?
If I do need a protocol adapter, will the older style red 8811 style work with the 8800? I can get a deal on one of those if needed.
Thanks to anyone that can help!!!!!!
Comments
Last question...
When directly connecting the processor to the TStat, does ground of the 485 get connected to the "C" terminal of the TStat?
As far as I can tell, I connect A+,A-,B+, and B- of the termostat to TX+,TX-,RX+, and RX- on the serial port of the processor. But what about ground? Is ground not needed because of RX- and TX-?
Thanks!!!!
1 B-
2
3
4 A+
5 REF
6 B+
7
8
9 A-
Thanks for helping me get this figured out!
As I mentioned, you don't need to. The TX/RX +/- are balanced signals, and shouldn't need a signal ground. The only time I have ever used the REF terminal was for a drain on the cable's shield, and then I only connected it on one end.