Defining The Signalling Bits For The Direct Inward Dial (Did) Protocol; Defining The Signalling Bits For The Ground Start Protocol - Comdial DXP Plus Manual

Troubleshooting The DXPT1 Installation
3.2

Defining The Signalling Bits For The Direct Inward Dial (DID) Protocol

FUNCTION
INCOMING CALL
Idle
CO goes off-hook
DXP sends wink
DXP after wink
Far end DP
Far end wait FR ANS
DXP answers call
3.3

Defining The Signalling Bits For The Ground Start Protocol

FUNCTION
OUTGOING CALL
Idle
PBX grounds ring
PBX grounds tip
PBX removes ring ground
PBX loop closed
Dial pulsing
Dialing CMPL
INCOMING CALL
Idle
CO grounds tip
Ringing interval
PBX presents call
PBX answers call
Normal talking STAT
DISCONNECT PBX
Talking state
PBX opens loop
CO removes tip ground
CO ABANDONS INCOM...
Talking State
CO removes tip ground
PBX opens loop
PBX ABANDONS BEFORE
CO HAS RETURNED TIP
GROUND
PBX waiting tip ground
PBX removes ring ground
TRANSMIT RECEIVE
A B A
0 0 0
0 0 0
1 1 1
0 0 1
0 0 DP
0 0 1
1 1 1
TRANSMIT RECEIVE
A B A
0 1 1
0 0 1
0 0 0
0 1 0
1 1 0
DP 1 0
1 1 0
0 1 1
0 1 0
0 1 0
0 1 0
1 1 0
1 1
0
1 1 0
0 1 0
0 1 0
1
1 0
0 1 0
0 1 0
0 0 1
0 1 1
Throubleshooting The DXPT1 Installation – 11
EIA/TIA 464-A
STANDARD
B
X
X
X
X
X Make=1, Break=0
X
X
EIA/TIA 464-A
STANDARD
B
X
X
X
X
X
X "1" vs DP for DTMF
X
X
1
0
1
X
X
X
X
1 Idle state
X
1 CO hangs up
1 Idle state
X
X
IMI89–207