Nortel Networks Circuit Card 311 User Manual
Page 285
Installation
285
For 75 ohm coaxial installations, E1 signaling for all 30 channels is
transmitted over P2 connector pins 1, 3, 9, and 11 though an adapter and
out two coaxial connectors Tx (transmit) and Rx (receive). Tx is the LEI
output, and Rx is the LEI input from the E1 stream. E1 transmit and receive
pairs must be turned over between the LEI and the CPE that is hardwired
without carrier facilities. If the LEI is connected through E1 carrier facilities,
the transmit and receive pairs must be wired straight through to the RJ48
at the Telco demarc, the LTU, or other E1 carrier equipment. The E1 CPE
at the far end has Tx and Rx wired straight from the RJ48 demarc at the
far end of the carrier facility.
External Alarm Connections
P3 connector pins 1, 2 and 3 can be plugged into any external alarm-sensing
hardware. Plug the DB9 male connector labeled "P3" into an external
alarm. These connections are optional, and the LEI functionality is not
affected if they are not made.
The MMI monitors the E1 link for specified performance criteria and reports
on problems detected. One of the ways it can report information is through
this external alarm connection. If connected, the LEI’s microprocessor
activates the external alarm hardware if it detects certain E1 link problems it
has classified as alarm levels 1 or 2. See
interface software" (page 292)
for a detailed description of alarm levels and
configuration. If an alarm level 1 or 2 is detected by the MMI, the LEI closes
the contact that is normally open, and opens the contact that is normally
closed. The MMI command "Clear Alarm" returns the alarm contacts to
their normal state.
MMI Connections
P5 connector pins 2, 3, 5, 7 and 9 are used to connect the LEI to the MMI
terminal, connecting LEIs in a daisy chain for access to a shared MMI
terminal. When logging into a LEI, "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 LEIs can be linked, located in up to 16 separate IPE shelves, to
one MMI terminal using the daisy chain approach.
If only one LEI is installed, cable from the DB9 male connector labeled "P5"
(toward 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 female connector labeled
"P4" (away from MMI terminal).
If two or more LEIs 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 LEIs. See
Figure 60 "LEI card - connecting two
Nortel Communication Server 1000
Circuit Card Reference
NN43001-311
01.04
Standard
Release 5.0
23 May 2008
Copyright © 2003-2008, Nortel Networks
.