User's Guide

COMSPHERE 3821Plus Modem
2-4 February 1998 3821-A2-GB20-30
Install the Circuit Card
Slide the 3821Plus card into its slot in the 3000 Series
Carrier. Press firmly until the back edge of the card seats
in the socket of the DTE interface assembly.
Figure 2-4 shows circuit cards in a carrier in which the
NIM and DTE interface assembly were installed on the
right side of the backplane.
495-1479
7
Figure 2-4. Installing the Card Into the Carrier
" Procedure
1. Turn the circuit pack lock until it is vertical, locking
the 3821Plus card in place. See Figure 2-5.
2. When all cards are installed and locked in place,
tighten the screws on the DTE interface assembly.
Front Panel
495-1480
0
Figure 2-5. Circuit Pack Lock
Connect the DTE
To connect the DTE to the modem, you can use two
DB25 to 8-position modular adapters and an 8-pin
RJ45-type modular cable instead of an RS-232 cable with
DB25 connectors. Because of the large number of cables
required for typical 3821Plus installations, the slimmer
modular cable is recommended.
The connectors on the DTE interface assembly are
labeled, from top to bottom, A, B, and C. These markings
show which modem on a card is associated with each
connector.
" Procedure
1. Connect the DB25 adapter or the connector on an
RS-232 DTE cable to one of the DB25 connectors
on the DTE interface assembly. Use a small
screwdriver to fasten the connector to the
backplate.
2. Connect the DB25 adapter or connector on the
cable to the DB25 connector on the DTE. Use a
small screwdriver to fasten the cable to the DTE.