Nortel Circuit Card Installation Manual page 649

Table 198
DX signaling – outgoing calls with originating party release
Condition
Idle
Seizure
(dial tone from far-end: far-end ready for digits)
Digits
Far-end answers
Far-end on hook first
Network taken down and trunk idled when
near-end goes on hook
Near-end on hook first, network taken down
Far-end on hook, trunk idled
Table 199
DX signaling – incoming calls with originating party release (Part 1 of 2)
Condition
Idle
Seizure
(dial tone to far-end: near-end ready for digits)
Digits
Near-end answers
Table 198 and Table 199 show call-connection and take-down sequencing for
DX signaling. Table 200 on
sequencing where the E&M trunk card is used in a tandem PBX.
NT8D15 E&M Trunk card
page 650 and Table 201 on
Current in
signaling lead
No current flow
Current flow
Current flow interrupted
for each pulse
No current flow
Current flow
No current flow
Current flow
No current flow
Current in
signaling lead
No current flow
Current flow
Current flow interrupted
for each pulse
No current flow
Circuit Card
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State of trunk
detector
High
High
High
Low
High
High
Low
High
State of trunk
detector
High
Low
Low-high-low
for each pulse
Low
Description and Installation