Epson C82305 - Manual (Page 22)

HARDWARE DESCRIPTION
1. I/F board connector: EIA standard 25-pin D-SUB
female connector.
2. For signal description and pin assignment, refer to
the table below:
Table 9. Signal Description and Pin Assignment
Pin No. Signal name Direction Description
1
protective
Ground
— Chasis ground
Transmitted
2
Data (TXD)
Text Transmitted serial data
3
Received Data
(RXD)
Ill Received serial data
4
Request to
o u t
This signal is always at the
Send (RTS) positive EIA level.
I I
7 Signal Ground In
Return path for data and
control signals.
Reverse
1 1 Channel Out
(=2nd RTS)
Data Terminalk t
20 O u t
Ready (DIR)
This
signal is at he positive
EIA Level when the printer is
ready to accept data entry
and at the negative EIA
level when the printer is not
ready to accept data entry
Operator can invert the
polarity of the signal with
jumper 15.
19