Epson TM T70 Technical Reference Manual page 40

Connecting the serial interface (RS-232C) cable
Be sure to turn off the power supply for both the printer and host computer before
connecting the cables.
WARNING
1
Insert the interface cable connector firmly into the interface connector
on the connector panel.
2
When using connectors equipped with screws, tighten them to secure
the connectors firmly.
3
When using interface cables equipped with a grounding line, attach the
ground line to the screw hole marked "FG" on the printer.
4
Connect the other end of the interface cable to the host computer.
Drawer kick-out connector
Power supply connector
40
DK
24V
FG
Interface connector
FG