Epson FX-870 User Manual page 138

Signal
GND
NC
SLCT IN IN
Note:
The column heading "Direction" refers to the direction of
signal flow as viewed from the printer.
"Return" denotes the twisted-pair return, to be connected at
signal ground level. For the interface wiring, be sure to use a
twisted-pair cable for each signal and to complete the
connection on the return side.
All interface conditions are based on the TTL level. Both the
rise and fall times of each signal must be less than 0.2
microseconds.
Data transfer must be carried out by observing the ACKNLG
or BUSY signal. Data transfer to this printer can be carried out
only after receipt of the ACKNLG signal or when the BUSY
signal is LOW.
Direction Description
Same as for pins 19-30
Not used
Pulled up to 5V through 3.3 kQ
OUT
resistance
The DCl/DC3 code is valid only when this
signal is HIGH. This signal is factory-set to
HIGH.
Technical Specifications
1
7-13