Oki Microline 3390 User Manual page 310

Term
Number of stop bits
Transmission protocols
Interface connection
Interface signals
The interface signals, pin assignment and circuits of the RS-232C
coresident interface are not mentioned again here, as they are like
the simple RS-232C interface, described earlier in this chapter..
Current Loop Interface
Pin Signal
1 Protective Ground, PG
2 - 6 ---
7 Signal Ground, SG
8 ---
9 Current Loop, D+
Receive loop
10 Current Loop, D-
Receive loop
11,12 ---
13 Signal Ground, SG
14 - 17 ---
18 Current Loop, B+
Send loop
19 Current Loop, B-
Send loop
20-25 ---
Description
one or more bits
three protocols
on printer side: 25-pin plug, DB-25S
or equivalent,
on cable side: 25-pin plug, DP-25P
or equivalent
see table for interface signals
Direction Description
--- connected to the
printer's casing
--- not assigned
--- Signal Ground
--- not assigned
to printer printer receive signal
for serial data
to printer return line for D+ signal
--- not assigned
--- Signal Ground
--- not assigned
from printer printer send signal for
serial data *
from printer return line for D+ signal
--- not assigned
Appendix D: Interface Data
Pin assignment
D-23