Nortel Circuit Card, Installation Manual, Page: 649 / 908

NT8D15 E&M Trunk card Page 649 of 906
Circuit Card Description and Installation
Table 198 and Table 199 show call-connection and take-down sequencing for
DX signaling. Table 200 on
page 650 and Table 201 on page 651 show
sequencing where the E&M trunk card is used in a tandem PBX.
Table 198
DX signaling – outgoing calls with originating party release
Condition
Current in
signaling lead State of trunk
detector
Idle No current flow High
Seizure
(dial tone from far-end: far-end ready for digits) Current flow High
Digits Current flow interrupted
for each pulse High
Far-end answers No current flow Low
Far-end on hook first Current flow High
Network taken down and trunk idled when
near-end goes on hook No current flow High
Near-end on hook first, network taken down Current flow Low
Far-end on hook, trunk idled No current flow High
Table 199
DX signaling – incoming calls with originating party release (Part 1 of 2)
Condition
Current in
signaling lead State of trunk
detector
Idle No current flow High
Seizure
(dial tone to far-end: near-end ready for digits) Current flow Low
Digits Current flow interrupted
for each pulse Low-high-low
for each pulse
Near-end answers No current flow Low