Installation
36
Model 3088A Series User Manual
3 • OnSite installation
Connecting the Model 3088A serial interface
This section describes how to connect the serial ports to your serial equipment.
The Model 3088A versions listed below provide the following types of built-in serial interfaces:
•
Model 3088A/
A
provides an
RS-232
interface on a DB-25 female connector
•
Model 3088A/
CA
provides a
V.35
interface on a DB-25 female connector.
•
Model 3088A/
D
provides an
X.21
interface on a DB-15 female connector.
Connecting the Model 3088A to a “DCE” or “DTE” device
The Models 3088A/A, 3088A/CA and 3088A/D provide serial interfaces for connecting to a DCE or DTE
device. The serial interface default configuration is DCE for connection to DTE (data terminal equipment)
such as a router. However, the serial interface on the 3088/A may be configured as DTE (data terminal equip-
ment) for connection to DCE such as a modem or multiplexer. When the 3088A is set as CO, the internal
serial interface is always configured as DCE. When the CO is set to external, the serial interface is configured as
DTE.
Figure 7. Connecting the Model 3088A/D to X.21 DTE or DCE
You may change the DCE/DTE orientation from the default position (DCE) by turning DIP switch S1-5 to
the ON position (refer to
table 3
on page 23).
The interconnecting cables shall be acceptable for external use
and shall be rated for the proper application with respect to volt-
age, current, anticipated temperature, flammability, and
mechanical serviceability.
CAUTION
Straight-Through 15-pin
D-Sub Cable
DSL Span
Remote Model 3088A
Router (DTE)
OR
Mux (DCE)
™