I've got a real problem here, with two SPA3102's not detecting a ring from the PSTN.
I figured it's likely to be some voltage thing, seeing as how if I connect the 3102's FXO to an FXS on our PBX - things work fine. But connecting to the Telstra PSTN - things don't work. Anyway, I called Xnet support and confused someone, who should hopefully call me back later. But seeing as how we're an office full of geeks and just happened to have an budget oscilliscope lying under one of the desks - we figured what the hell lets waste some time!
So a couple of surprising things, the two Telstra lines have completely different ringing charactaristics. Both lines switch polarity while ringing, so -50v or whatever so they only peak at around +60 volts and drop to -120v, but for the "silence" between rings - one line holds at -50v, while the other switches back to +50v!?!?!
Anyway, I figure there must be someone in here who can tell me WTF is going on, and who's responsible for the SPA3102 failing to ring on the FXS side when a TelstraClear line is connected to the FXO - Telstra? or Xnet?
FXO - TelstraClear Line 1 (50v on hook, ~50v between rings)
FXS - Standard Telephone
= No ring on FXS
FXO - TelstraClear Line 2 (50v, ~-40v between rings)
FXS - Standard Telephone
= No ring on FXS
FXO - PBX (-25v)
FXS - Standard Telephone
= Yay ringing!!