Removing And Replacing The Model 3920Plus Modem; Model 3921Plus Modem Installation - Paradyne COMSPHERE 3920Plus Technical Reference Manual

COMSPHERE 392xPlus Modems

Removing and Replacing the Model 3920Plus Modem

To remove and replace the Model 3920Plus modem, perform the following steps:

Model 3921Plus Modem Installation

The Model 3921Plus modems are designed for installation in a COMSPHERE 3000 Series Carrier,
which supplies both the operating power and the leased and/or dial network connections. For
additional information about the COMSPHERE 3000 Series Carrier, refer to the COMSPHERE
3000 Series Carrier, Installation Manual.
The COMSPHERE 3000 Series Carrier has 17 slots that hold up to 8 Model 3921Plus multiport
modems or 16 Model 3921Plus singleport modems, and one shared diagnostic unit (SDU). The
SDU is required when the modems in the carrier are controlled by an NMS, or when multiple
carriers in a cabinet configuration are to be controlled by a single shared diagnostic control panel
(SDCP). The SDCP of the COMSPHERE 3000 Series Carrier is the user interface to the
Model 3921Plus modem. A single SDCP can control up to eight carriers.
The installation of a Model 3921Plus modem varies slightly if an SDCP is installed on the front of
the carrier. To install a Model 3921Plus modem into the carrier without an SDCP, perform the
following steps:
2-8
1. Make sure the modem is offline. Press the modem's back panel power switch to OFF.
2. Disconnect the power cord from the ac power outlet.
3. Disconnect the dc power cable from the connector on the back of the modem.
4. Disconnect the leased-line and dial modular cord(s) from the modem's back panel.
5. Disconnect the DTE interface cable(s) from the modem's back panel.
If the modem is to be removed for service, return it to the company using the procedures
described in Government Requirements and Equipment Return
6. Install the replacement modem as described in the
section of this chapter, and configure it the same way as the modem being replaced.
When removing the Model 3921Plus from the carrier, always
use a ground strap when handling the modem. Always store
the Model 3921Plus in an antistatic bag when it is removed
from the carrier.
1. At the back of the carrier, install the connector plates
use the same slot positions as that intended for the modem.
Loosely fasten the plate(s). This allows for slight adjustments later when installing the
modem.
Model 3920Plus Modem Installation
CAUTION
October 1998
in Chapter 1, Introduction.
(Figure 2-3). Make sure the plate(s)
3920-A2-GH30-40