Epson LX-80, Operating Manual

Page: 179 / 193

Signal Return
Signal
Direc-
Description
Pin Pin
tion
13 - - - Pulle d up to +5 vo l ts through 3.3 K
ohm resistance .
14
-
AUTO FEED IN When this signal is LOW , the pap er is
XT automatically fed 1 line after pr in ti ng.
(The signal level can be fixed t o t h i s by
setting DIP switch 2-3 to ON .)
15
- NC
-
Unused.
16
-
OV
-
Logic ground level .
17 - CHASSIS - Printer ' s chassis 9round , which i s iso -
GND lated from the logiC ground .
18
-
NC
-
Unused .
19-30 - GND - Twisted-pair return signal grou nd
level .
31 - INIT IN When this level becomes LOW , the
printer controller is reset to its p ower-
up state and the print buffer is c l ea r ed .
This level i s usually HIGH ; i t s pulse
w i dth must be more than 50 mic-
roseconds at the receiving te rm i nal .
32
- ERROR OUT This level becomes LOW whe n the
printer i s in :
1) Paper-end state .
2) Off-line.
3
) Error state .
33
-
GND
-
Same as for pins 19-30 .
34 - NC - Unused .
35
- - - Pulled up to +5V through 3 . 3K ohm
resistance .
36 - SLCTIN IN Data entry to the printer is po ssible
only when this level is LOW ; DI P
switch 2-2 is set for this at t he f acto ry.
Notes:
1 . Th e co lumn h ea din g " Dir ec tion " r efe r s to th e dir e cti o n of s i g n al
f l ow as v iewed fr o m th e print e r .
2. " R e turn " d e n o t es th e twi s t e d-p ai r return , t o be c o nn ect ed at
si gn a l groun d l eve l . F or th e int e rf a ce wiring , be s ur e to u se a
twiste d - p a ir ca ble for e a ch s ign a l a nd to compl e te th e c onn e ct ion
o n t h e r e t urn s id e . T o pr eve nt noi s e , th ese cabl es s h oul d be
s h ie ld e d and co nn ecte d t o th e ch ass i s o f the ho s t compu ter o r the
p ri nt er .
3. A ll i nt e rface co nditi o n s are ba se d on TTL l e vel . B o th th e rise
a nd th e fa l l ti m es of eac h s i g n a l mu s t b e l ess th a n 0 .2 mic-
roseco nd .