Nortel Networks Circuit Card User Manual
Page 219
NT5D11 and NT5D14 Lineside T1 Interface cards
Page 219 of 906
Circuit Card
Description and Installation
One of the ways it can report information is through this external alarm
connection. If connected, the lineside T1 card’s microprocessor activates the
external alarm hardware if it detects certain T1 link problems that it has
classified as alarm levels 1 or 2. See “Man-Machine T1 maintenance interface
software” on
for a detailed description of alarm levels and
configuration. If an alarm level 1 or 2 is detected by MMI, the lineside T1
card will close the contact that is normally open, and will open the contact that
is normally closed. The MMI command Clear Alarm will return the alarm
contacts to their normal state.
MMI connections
P5 connector pins 2, 3, 5, 7 and 9 are used to connect the lineside T1 card to
the MMI terminal and daisy chain lineside T1 cards together for access to a
shared MMI terminal. When logging into a lineside T1 card, “control 2” is
asserted by that card, which informs all of the other cards not to talk on the
bus, but rather to pass the data straight through. The pins labeled “control 1”
are reserved for future use. As with the external alarm connections, MMI
connections are optional. Up to 128 lineside T1 cards, located in up to 16
separate IPE shelves, can be linked to one MMI terminal using the daisy
chaining approach.
If only one lineside T1 card is being installed, cable from the DB9 female
connector labeled “P5” (towards MMI terminal) to one of the COM ports on
the back of any TTY, a PC running a terminal emulation program, or a
modem. For installations of only one card, no connection is made to the DB9
male connector labeled “P4” (away from MMI terminal).
If two or more lineside T1 cards are being installed into the system, the MMI
port connections can be daisy-chained together so that only one MMI
terminal is required for up to 128 lineside T1 cards. See Figure 33 on
. Cards can be located in up to 16 separate IPE shelves. Any card slot
in the IPE shelf can be connected to any other card slot; the card slots
connected together do not need to be consecutive.