Epson Action Laser - Manual (Page 204)

Interface Specifications
DIP switches
Select the required serial interface by setting the DIP switches on the
back of the printer as follows:
1 2 3 4 5 6 7 8
RS-232C OFF OFF OFF OFF * OFF O F F O N
RS-422A OFF OFF OFF OFF OFF ON ON OFF
* If DIP switch 5 is turned ON when the RS-232C serial interface is in use, pin
25 on the connector is set to +5V; if the DIP switch is turned OFF, the pin on
the connector is not used.
B-14 Technical Specifications