The DCE/DTE strap is located near the DB15 connector on the top side of the board. The arrows on the top of the strap indicate the configura- tion of the X.21 port (for example, if the DCE arrows are pointing toward the DB-15 connector, the X.21 port is wired as a DCE). Reverse the DCE/DTE orientation by pulling the strap out of its socket, rotating it 180º, then plugging the strap back into the socket. You will see that the DCE/DTE arrows now point in the opposite directions, showing the new configuration of the X.21 port.
Note If the 2707/D is configured as a DTE, the clocking mode must be set for external clock.
4.3 POWER CONNECTION
Universal AC Power (100-240VAC)
The Model 2707 uses a 5VDC, 2A universal input 100-240VAC, power supply (center pin is +5V). The universal input power supply has a male IEC-320 power entry connector. This power supply connects to the Model 2707 by means of a barrel jack on the rear panel. Many interna- tional power cords are available for the universal power supply.
The Model 2707 powers up as soon as it is plugged into an AC outlet-- there is no power switch.