Epson MX-80 Technical Manual page 15

Table 2.1 Pin Assignment of CN1 (cont.)
Signal Return
Signal Direction
Description
Pin No. Pin No.
31 - INIT In 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
50ILs at the receiving terminal.
32 ERROR Out The level of this signal becomes "LOW" when the
printer is in-
1. PAPER END state
2. OFF-LINE state
3. Error state
33 - GND
-
Same as with Pin Nos. 19 to 30.
34 - NC - Not used.
35 Pulled up to +5V through 4.7 kfl resistance.
36 - SLCTIN In Data entry to the printer is possible only when the
level of this signal is "LOW" (Internal fixing can be
carried out witn DIP SW pin 1-8. The condition at the
time of shipment is set "LOW" for this signal.)
NOTES 1: "Direction" refers to the direction of signal 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 connected to the chassis of the host computer and the printer, respectively.
3: All interface conditions are based on TTL level. Both the rise and fall times of each signal must be less
than 0.2 ILS.
4: Data transfer must not be carried out by ignoring the ACKNLG or BUSY signal.
(Data transfer to this printer can be carried out only after confirming the
ACKNLG
signal or when the
level of the BUSY signal is "LOW".)
2-3
REV. A