Installation manual

3
3920-A2-GK41-60 February 2002
Model 3920Plus Singleport Modem
The Model 3920Plus singleport is a standalone modem (Figure 1) capable of either 4-wire/2-wire leased-line or
dial operation. This modem is controlled using either AT commands or the DCP. The DCP consists of a liquid
crystal display (LCD), three function keys, four directional keys, and a row of 13 LED status indicators. For a
better understanding of DCP operation, refer to Chapter 3, DCP Operation, in Document No. 3920-A2-GH30.
Model 3920Plus Multiport Modem
The Model 3920Plus multiport is a standalone modem (Figure 1), with an integral time division multiplexer
(TDM) and a modem sharing device (MSD) as standard equipment. The TDM provides time division
multiplexing of up to four independent ports over point-to-point lines using the V.34 family or V.32 family
modulation. The MSD allows multiple physical ports on a tributary modem to share a single communication
channel using the V.34 family, V.32 family, or TMp modulation. The TDM/MSD multiplexer (commonly referred
to as “mux”) can be enabled or disabled to allow a greater degree of application flexibility.
The 3920Plus multiport modem also operates over a 4-wire/2-wire leased or dial network and is controlled using
the same DCP employed on the Model 3920Plus singleport standalone modem.
DIAGNOSTIC
CONTROL
PANEL
LCD AND
KEYPAD
STATUS
INDICATORS
SPEAKER
POWER
SUPPLY
POWER
CORD
496-14684-01
LEASED
Model 3920 Plus Singleport and
Multiport Housing
Singleport Modem
Back Panel
Multiport Modem
Back Panel
POWER
ON/OFF
DIAL
DTE 1
NMS
POWER IN
DTE 2
DTE 3
DTE 4
POWER
ON/OFF
LEASED
DIAL
DTE 1
NMS
POWER IN
Figure 1. Model 3920Plus Standalone Singleport and Multiport Modems