User manual
Appendix B. Signaling States Vs. Mode of Operation
30 FXS+ Dual Voice Option Module 61200.080L1-1
Ground start signaling provides its own tip ground in
response to ring ground in the Tandem Mode. See
Table B-B.
Table B-B
Tandem Mode
The A and B signal bit states on the DS-1 signal are as
follows:
0 = logic 0 is the DS-1 stream
1 = logic 1 is the DS-1 stream
X = value is not significant
Loop Open = phone on-hook
Loop Closed = phone off-hook
FXS+
2W Input
(Outgoing call from FXS+)
Loop Open
Loop Closed
Loop Closed
Loop Closed
Loop Closed
0
0
1
0
1
RX A RX B TX A
FXS+
2W Output
Switch
to
FXS+
Condition
0
1
1
1
1
TX B
X
X
X
X
X
0
1
1
1
1
—
—
Dial Tone
Idle
Idle
Wink
Wink Done
Answer Far End
Loop Open
Loop Closed
Loop Closed
0
1
1
X
X
X
0
0
1
0
0
1
Idle
Far end off hook
Far end off hook
-
Ringing
Answers
(Incoming call to FXS+)