How can I identify which is the A and B wire coming in from outside?
There is no earth wire supplied.
M.Joshi
BT A/B wires
Apr 03, 2012
3 Replies
Assuming it's RS-422, when idle the "A" line is negative with respect to the "B" line.
Rich Webb Norfolk, VA
Why ... ?
Arfa
Ah no, I was referring to UK telephone line A/B wires. BT - British Telecom.
M.Joshi
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