Filter
Top Products
Modem Installation
2-113920-A2-GN31-30 November 1996
Removing and Replacing the Model 3921
Plus
Modem
CAUTION
When removing the Model 3921
Plus
modem from the carrier,
always use a ground strap when handling the modem. Always
store the Model 3921
Plus
modems in an antistatic bag when it
is removed from the carrier.
It is not necessary to power down the carrier to remove and replace the Model 3921Plus modem.
Perform the following steps:
1. Rotate the circuit pack lock until the release tab is exposed (Figure 2-4).
2. Press down on the release tab and pull the modem away from the carrier’
s backplane.
392x
Plus
Modem Power-Up
Once your modem is properly connected to the power supply
, leased and/or dial lines, and the
DTE, press the modem’
s back panel power switch to the ON position. The modem begins a
power-up self-test, in which all DCP LEDs light. This test takes several seconds to perform, and
verifies the operation of most hardware components within the modem. If successful, the LCD
displays
Power on Selftst Passed and continues to the Top-Level menu screen.
F1
Power On Selftst
Passed
F2
F3
If a failure occurs during the self-test, the LCD displays Power On Selftst Failed for several
seconds. The LCD then displays the T
op-Level menu screen with the message
Power on Fail
appearing on the top line of the LCD. Although a failure has occurred, the modem will attempt to
operate. This allows you to activate a more thorough self-test using the Test branch. Refer to the
T
est
section in Chapter 3.
Selecting Factory Configuration Options for 392x
Plus
After
the modem passes the power
-up self-test, configure it for operation using one of the six
factory preset configurations.
The 392xPlus
modems have six factory preset templates that contain the most commonly used
configuration options (straps) for Synchronous Leased (Answer or Originate), Asynchronous
Leased (Answer or Originate), Trellis Multipoint (Control or Tributary), Asynchronous Dial,
Synchronous Dial, and UNIX Dial hardware network configurations. Your modem ships from the
factory with the Synchronous Leased (Answer) default configuration options stored in memory. If
Synchronous Leased (Originate), Asynchronous Leased (Answer or Originate), Trellis Multipoint
(TMp) (Control or Tributary), Async Dial, Sync Dial, or UNIX Dial is more appropriate for your