Epson MX-82 Operation Manual page 93

NOTES: 1. "Direction" refers to the direction of signal flow as viewed from the
printer.
2. "Return" denotes "TWISTED PAIR RETURN" and is to be connected at
signal ground level.
As to the wiring for the interface, be sure to use a twisted-pair cable for
each signal and never fail to complete connection on the Return side.
To prevent noise effectively, these cables should be shielded and con-
nected to the chassis of the host computer and the printer, respective-
ly.
Table A2-1 (cont'd)
This signal indicates that the printer
is in the selected state.
With this signal being at "LOW" level,
the paper is automatically fed one line
after printing.
(The sig nal level can be fixed to "LOW"
with DIP SW pin 2-3 provided on the
control circuit board.)
Not used.
Logic GND level.
Printer chassis GND.
In the printer,
logic
Not used.
When the level of this signal becomes
"LOW", the printer controller is reset to
its initial state and the print buffer is
cleared. This signal is normally at "HIGH"
level, and its pulse width must be more
than 50~ at the receiving terminal.
The level of this signal becomes
"LOW" when the printer is in -
1. PAPER END state
2. OFF-LINE state
3. Error state
Same as with Pin Nos. 19 to 30.
Not used.
Pulled up to +5V through 3.3k.G
resistance.
Data entry to the printer is possible only
when the level of this signal is "LOW".
(Internal fixing can be carried out with
DIP SW pin l-8. The condition at the
time of shipment is set "LOW" for this
signal.)
- 8 8 -
Description
the
chassis GND and the
GND are isolated from each other.