In this example, the DCE/DTE strap is
configured for DCE because the “DCE” label
on the strap is pointed toward the
X.21 connector
X.21 connector
Hardware Installation
31
Models 2603, 2621, and 2635 User Manual
3
• Initial Configuration
Figure 9. Location of DTE/DCE board
3.
The DTE/DCE daughter board is installed at the factory with the DTE label and arrows pointing towards
the X.21 connector (DTE configuration). To change to DCE configuration, lift the daughter board from
the connector, turn it around so that the DCE label an arrows point to the X.21 connector, and place it
back on the connector. The X.21 port is now configured as a DCE.
Note
Wh
e
n the X.21 port is configured as a DTE, the clocking mode for the port
must be set for external clock.
4.
Re-assemble the case.
The interface cable has been installed, go to section
“Installing the AC power cord”
on page 33.
Installing an interface cable on the OnSite 2635’s V.35 interface port
The OnSite Model 2635 comes with a V.35 interface presented on a DB-25 female connector (see
figure 10
).
CAUTION
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.
The Model 2635 V.35 (DB-25) interface is configured internally as a DCE. However, when using the Patton
cable with the 2635, the V.35 interface at the M/34 end of the cable is a DTE (see
figure 11
). In other words,
the Patton DB-25 to M/34 cable is a sync null modem cable.
