Interface Specification; Parallel Interface (Forward Channel) - Epson LQ-670 Service Manual

LQ-670 Service Manual

1.3.2 Interface Specification

This printer provides bi-directional 8-bit parallel interface and Type-B optional interface slot as standard.

1.3.2.1 Parallel interface (Forward channel)

[Transmission mode]
[Adaptable connector]
[Synchronization]
[Handshaking]
[Signal level]
Pin No. Signal Name
1 /STROBE
2 9 DATA1 8
10 /ACKNLG
11 BUSY
12 PE
13 SLCT
14 /AFXT
31 /INIT
32 /ERROR
36 /SLIN
18 Logic H
35 +5V
17 Chassis
16,33 GND
19-30
15,34 NC
Note) *In/Out shows the direction of signal flow from the printer's point of view.
Note) If the signal is "LOW" and active state, the signal is marked with "/".
1-18
: 8 bit parallel, IEEE-1284 compatibility mode
: 57-30360 (Amphenol) or equivalent
: /STROBE pulse
: BUSY and /ACKNLG signals
: TTL compatible (IEEE-1284 level 1 device)
Table 1-19. Connector Pin Assignment and Signals
Return In/Out *
GND
Pin
19 In
In
20 27
28 Out
29 Out
28 Out
28 Out
30 In
30 In
29 Out
30 In
---- Out
--- Out
--- ---
--- ---
--- ---
Function description
Stroke pulse. Input data is latched at falling edge of
the signal.
Each signal represents information of parallel data
from 1 bit to 8 bit. The data is 1 at "HIGH" and is 0
at "LOW".
This signal (negative pulse) indicates that the printer
has received data and is ready to accept next one.
The pulse width is 5 s.
This signal's "HIGH" level indicates that the printer
is not ready to accept data. On the other hand,
"LOW" means the printer can take data.
(Refer to the next page for conditions when this
signal becomes high level)
This signal's "HIGH" level indicates that the printer
is in a state of paper-out error.(Refer to the next
page for the condition when this signal becomes
high level.)
Always at high level when the printer is powered on.
Not used.
This signal's negative pulse initializes printer.
This signal's low level means the printer is in a state
of error. (Refer to the next page for conditions when
the signal becomes low level)
Not used.
This line is pulled up to +5V through 3.9 k
This line is pulled up to +5V through 1.0 k
Chassis GND.
Signal GND.
Not connected.
resistor.
resistor.
Rev. A