Installation manual

6
COMSPHERE 392x Plus Models
The 392xPlus family is available in two models: the Model 3920Plus, a 4-wire/2-wire standalone modem, and the
Model 3921Plus, a carrier-mounted version of the standalone unit.
Standalone Model 3920 Plus 4-Wire/2-Wire Modem
The standalone Model 3920Plus modem (Figure 1) is capable of either 4-wire/2-wire leased-line or dial
operation. The modem is controlled using the diagnostic control panel (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-GN31.
The rear of the modem contains an ON/OFF power switch, a low voltage dc power connector, an 8-pin modular
connector for leased-line connection, an 8-pin modular connector for dial-line connection, a 4-pin modular
connector for network management, and four DTE connectors.
Figure 1. Model 3920 Plus