Ground Start Operation - Avaya G700 Maintenance Manual

6 Avaya MultiVantage Software-Controlled Maintenance:
Incoming Call:
1 . CO Applies Ringing Voltage
a . PBX Response: Detect ringing current
2 . PBX Off-Hook (Answer Message): Close Loop
a . CO Response: Trip ringing, provide loop current
3 . PBX On-Hook (Drop Message): Open Tip-Ring Loop, no Loop Current
a . CO Response: CO goes to idle state (see Note)
Note:

Ground Start Operation

Idle state:
Tip = open, Ring = CO Battery
Outgoing Call:
1 . PBX Off-Hook (Seize Message): Places ground on Ring
a . CO Response: Places ground on Tip
b . PBX Response: Close the loop
c . CO Response: Provide loop current
d . PBX response: Dial out digits
2 . PBX On-Hook first (Drop Message): Open the Tip-Ring Loop, no loop current
a . CO Response: Open circuit on Tip
3 . CO On-Hook first (Disconnect): Open circuit on Tip, no loop current
a . PBX Response: Open Tip-Ring loop
Incoming Call:
1 . CO Off-Hook (Seizure): CO applies ground on Tip and applies ringing voltage
a . PBX Response: Make trunk busy for outgoing calls
2 . CO Ringing: CO applies ringing voltage
a . PBX Response: Detect ringing, ring destination
3 . PBX Off-Hook (Answer Message): Close loop
a . CO Response: Trip ringing, provide loop current
4 . PBX On-Hook first (Drop Message): Open the Tip-Ring Loop, no loop current
a . CO Response: Open circuit on Tip
5 . CO On-Hook first (Disconnect): Open circuit on Tip, no loop current
Maintenance for S8300/S8700 and G700
555-234-101 — Issue 2 — October 2002
CO does not normally provide an On-Hook (Disconnect) signal. Exceptions
to this rule include Netherlands loop start and UK loop-calling guarded-
clearing.
CO-TRK (Analog CO Trunk)
121