Epson EPL-5500, Service Manual

Page: 23 / 145

Table 1-8. Parallel Interface Pin Assignments
Pin No. Signal Name I/O Description
1
STROBE
IN
STROBE is a strobe pulse used to read data from the host
computer. The pulse width must be more than 0.5
µ
sec.
Normally it is HIGH, and data is latched at the trailing edge of
this signal.
2-9
DATA 1-8
IN
DATA 1 to 8 are parallel data bits. When the signal is HIGH, the
data bit is 1, and when it is LOW, the data bit is 0. The most
significant bit (MSB) is DATA 8. The signal state must be
maintained for 0.5
µ
sec. on either side of the STROBE signal
active edge.
10
ACKNLG
OUT
ACKNLG is an acknowledge pulse with an approximate width
of 1 or 10
µ
sec. This signal goes LOW when the data reception is
completed, which indicates that the printer can accept new data.
Timing with the BUSY signal is specified through SelecType.
11
BUSY
OUT
The BUSY signal informs the host computer of the printer state.
When the signal is HIGH, the printer cannot accept data.
12
PE
OUT
The PE signal indicates paper empty for the standard tray
selected through SelecType or command, or for the optional
paper cassette. Paper empty is indicated by HIGH.
13
SLCT
OUT
Used in reverse mode.
14
AUTO-FEED
IN
Not used.
15
NC
—
Not used.
16
GND
—
Logic ground level.
17
CHASSIS GND
—
Connected to the printer chassis. The printer chassis GND and
the signal GND are connected to each other.
18
NC
—
Not connected.
19-30
GND
—
Ground level for the twisted pair return signal.
31
INIT
IN
The STROBE signal is ignored when this signal is LOW.
32
ERROR
OUT
This level goes LOW when the printer is:
•
Out of paper
•
Paper jam
•
In the error state
•
Off line
33
GND
—
Same as for pins 19 to 30.
34
NC
—
Not used.
35
+5
—
Pulled up to +5 V through 1.0K-ohm resistance.
36
SLCT IN
—
Used in reverse mode.
General Description EPL-5500 Service Manual
1-10 Rev. B