Serial Pin Assignments - Epson LQ-300 User Manual

Synchronization:
Handshaking:
Parity check
Connector:

Serial pin assignments

The following table lists the serial connector pin assignments and
describes their respective interface signals.
Pin No. Signal
Protective Ground (FG)
1
Transmitted Data (TXD/SD)
2
Received Data (RXD/RD)
3
Request to Send (RTS/RS)
4
Signal Ground (SG)
7
Reverse Channel
11
Data Terminal Ready
20
(DTR/ER)
Asynchronous
DTR protocol, XON/XOFF protocol,
ETX/ACK protocol (selectable)
Odd, even, or none (selectable)
EIA standard, 25-pin, D-SUB, female
connector
Direction Description
Printer's chassis ground
—
Printer has transmitted serial data
out
Printer has received serial data
In
Always positive
out
Return path for data control signals
—
Connected to Pin 20
out
Positive when the printer is ready to
out
accept data, and negative when
the printer is not ready
Appendix A-9