Appendix B. Signaling States Vs. Mode of Operation
61200.080L1-1
FXS+ Dual Voice Option Module
31
See Tables B-C and B-D for descriptions of FXS mode for
signaling states.
Table B-C
FXS+ Mode (Loop-Start)
FXS
FXS+
2W Input
RX A
RX B
TX A
TX B
2W Output
(Outgoing call from FXS+)
Loop Open
X
1
0
1
No Ringing (Idle)
Loop Closed
X
1
1
1
No Ringing
(Incoming call to FXS+)
Loop Open
X
0
0
1
Ringing
Loop Closed
X
0
1
1
No Ringing
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
