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