4
Model 3511 DSU Installation
This section includes the installation procedures for the Model 3511 DSU, which is
designed for installation in a COMSPHERE 3000 Series Carrier. Before installing the
DSU, verify that the carrier has been installed properly and is operational.

CAUTION:

Discharge any static electricity that may be present on your body by
touching a properly grounded object (e.g., cold water pipe, frame ground, or
data cabinet). Do not handle the circuit card unnecessarily.
The initial installation procedure for the Model 3511 DSU requires the installation of a
rear connector plate onto the rear of the COMSPHERE 3000 Series Carrier. After the
initial installation, the DSU can be installed and removed from the front of the carrier
without first disconnecting the DTE cables at the rear of the carrier.
P26 P25 P24 P23
P20 P19
J2 P22 J1 P21
NON-MODULAR DSUs MODEL 3511 DSU
REAR CONNECTOR PLATES
SCREW
SLOT
98-12302a
25-PIN
EIA-232-D
CONNECTORS
25-PIN V.35
CONNECTORS

Rear View of the COMSPHERE 3000 Series Carrier

NOTE:
When modular circuit cards are installed with non-modular cards in the same
carrier, modular circuit cards like the Model 3511 DSU must be installed on the left
side of the carrier.