Epson 10020 - Manual (Page 152)

Serial Port Pin Assignments
Pin no. Signal name
1 NC
2 TX
3 RX
4 RTS
5 CTS
6 DSR
7 GND
8 DCD
9-19 NC
20 DTR
21 NC
22 RI
23-25 NC
Direction Description
—
No connection
O Transmitted data
I
O
Received data
Request to send
I Clear to send
I Data set ready
—
Signal ground
I Data carrier detect
—
No connection
O Data transmit ready
—
No connection
I Ring indicator
—
No connection
Note: The following current loop functions are not supported:
Pin 9: +Transmit current loop data
Pin 11: -Transmit current loop data
Pin 18: +Receive current loop data
Pin 25: -Receive current loop data
B-8 Specifications