COMSPHERE 3000 Series Carrier
3-50 December 1994 3000-A2-GA31-80
The procedures are only for installing the modular and
non-modular DSU-TDM or DSU-MCMP circuit cards
that are physically attached. For information on adding the
TDM or MCMP option onto a modular or non-modular
DSU, see the COMSPHERE 3600 Series Data Service
Units, Models 3610 and 3611, Time Division Multiplexer,
Multichannel Multipoint, and Digital Bridge Options,
Applications Guide.
Preinstallation Inspection
Check the circuit card for physical damage. If you are
installing a modular circuit card, also check the rear
connector plate or connector module for damage. Ensure
that the connector pins are not damaged. If the circuit
card, rear connector plate, V.35 interconnect cable, or
connector module shows signs of damage, report it
immediately to your shipping representative and also to
your AT&T Paradyne representative.
Modular Circuit Card Installation
Before you begin the modular circuit card installation
procedure, you must install the Network Interface
Modules (NIMs), if required. For information on how to
install a NIM, see the Network Interface Installation
section earlier in this chapter.
NOTE
When a TDM or MCMP is
installed, there are two circuit
cards with two faceplates that
are physically attached. The
modular DSU-TDM or
DSU-MCMP circuit cards occupy
two slot positions in the carrier,
but they are installed as one.
Follow the instructions, keeping
in mind that there are two latches
and that a 6-port connector
module is used instead of a
2-port rear connector plate.
Also, when installing a TDM or
MCMP, make sure both modular
circuit cards are aligned in their
slots before sliding the cards into
place.
If installing a DDD NIM and a modular DSU-TDM or
DSU-MCMP circuit card, do not install the connector
module where it will interfere with the NIM’s J3 and J4
modular connectors.
To install a modular circuit card, proceed as follows,
referring to the appropriate Installation and Operation or
Applications Guide when necessary:
Procedure
1. At the rear of the carrier, set the tab on the rear
connector plate into the slotted groove on the
carrier’s backplane. If you are installing a
connector module, there are two tabs instead of
one. Make sure the connector plate uses the same
slot position intended for the modular circuit card.
2. Loosely fasten the screw attached to the rear
connector plate, allowing for slight adjustment
that may be needed when installing the modular
circuit card. If you are installing a connector
module, there are two screws (which must be
alternately fastened) instead of one.
3. Change any default hardware strap settings that
may be required before installing the modular
circuit card in the carrier. For example, straps that
determine:
•Permissive (default) or programmable DDD
interface switch.
•Enabled (default) or disabled test mode
indication jumper.
4. Using a Phillips screwdriver, loosen the screw
holding the circuit pack lock and rotate the lock to
the open position (refer to Figure 3-16). Open the
latch.
5. At the front of the carrier, hold the modular circuit
card vertically with the latch on its faceplate in the
open position. Then, insert the circuit card into the
top and bottom circuit card guides (Figure 3-37).
Slide the modular circuit card into the slot,
aligning the circuit card with the rear connector
plate, until the connectors seat firmly into the back
of the carrier. Remember, if you are installing a
TDM or MCMP, there are two modular circuit
cards and a connector module instead of one
modular circuit card and a rear connector plate.
Press the faceplate latch to secure the circuit card
into the rear connector plate, rotate the circuit
pack lock into the closed position (refer to
Figure 3-16), and tighten the screw.
If the carrier’s power transformer unit is operating,
the unit performs a self-test routine. After several
seconds, the modular circuit card completes its
power-up self-test in which all faceplate LEDs
light. If the circuit card fails the self-test, the Alrm
LED on the faceplate flashes.