6
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 3821
Plus
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.
Install Communications Software
A computer commands and controls a modem through communications software. This
software uses the AT command set to send instructions to the modem. A dumb
asynchronous terminal, however, does not require this software since it can directly
send AT commands.
The 3821
Plus
can be used with any major communications software. Refer to your
software’s user’s guide for installation procedures.
Select Factory Configuration Options
After the modem passes the power-up self-test, configure it for operation using one of
the factory preset configurations. The 3821
Plus
modem has several factory preset
templates that contain the most commonly used configuration options (straps) for:
H
Asynchronous Dial (shown as Async Dial on the SDCP)
H
Synchronous Dial (Sync Dial)
H
Synchronous Leased (Sync Leased, Answer or Originate mode)
H
UNIX hardware network (UNIX Dial)
H
Cellular mobile (Cellular(Mobile)), valid only if ETC is installed
H
Cellular PSTN (Cellular(PSTN)), valid only if ETC is installed
Your modem is shipped from the factory with the Async Dial default configuration
options stored in memory. If Sync Dial, Sync Leased, UNIX Dial, or Cellular is more
appropriate for your configuration, then you must change the factory setting using either
the SDCP or the AT command set as described in the following sections.
