User's Manual

Connecting the Model 3550 DSU to a DTE

The DSU’s rear panel has both a 25-pin EIA-232-D/V.24 connector and a 34-pin ITU-T

V.35 connector (used for higher operating speeds). You can use either interface.

When the unit is equipped with a TDM/Flex, either of these interfaces can be used as

Port 1. The TDM/Flex provides an additional interface to be used as Port 2. This is a

D-type connector. If the port is to operate at a speed greater than 19.2 kbps, use the

V.35 adapter to provide an interface between the TDM/Flex’s D-type connector and the

DTE cable’s V.35 connector.

Be sure to select the appropriate cable (EIA-232 or V.35) for your application.

 Procedure

1. Connect the plug end of the DTE cable to Port 1, either the EIA-232-D or the V.35

connector. Tighten the two holding screws.

2. Connect the other end of the cable to the appropriate port on the computer or DTE.

Tighten any holding screws.

3. If necessary, activate the port to match the interface: EIA-232 or V.35. The default

setting is EIA-232.

V.35 Interface

(Port 1)

EIA-232-D/V.24

Interface (Port 1)

EIA-232

Interface

(Port 2)

DSU with

TDM/FLEX

99-16299

To DTE

EIA-232-D/V.24

Interface

V.35

Interface

Low Voltage

AC Power In

To DTE

DSU

V.35 Adapter

V.35 Cable