Defining The Signalling Bits For The Loop Start Protocol - Comdial DXP Plus Manual

IMI89–207
3.4

Defining The Signalling Bits For The Loop Start Protocol

FUNCTION
OUTGOING CALL
Idle
PBX loop closed
PBX pulsing
Dialing CMPL
INCOMING CALL
Idle
CO sends ring
Interval between ring
PBX presents call
PBX answers call
Normal talking STAT
DISCONNECT PBX
PBX opens loop
Idle
CO ABANDONS INCOM...
CO applies ring
Interval between ring
CO abandons
PBX stop presenting
12 – Troubleshooting The DXPT1 Installation
Troubleshooting The DXPT1 Installation
TRANSMIT RECEIVE
A B A
0 1 0
1 1 0
DP 1 0
1 1 0
0 1 0
0 1 0
0 1 0
0 1 0
1 1 0
1 1 0
0 1 0
0 1 0
0 1 0
0 1 0
0 1 0
0 1 0
EIA/TIA 464-A
STANDARD
B
1
1
Waiting for dial tone
1
"1" vs DP for DTMF
1
1
0
1
1
X
X
X
1
0
1
1
1