Epson Stylus pro 7700m, Service Manual

Page: 18 / 139

Table 1-8 shows connector pin assignments and signal functions of the 8-bit parallel interface.
Table 1-8. Signal and Connector Pin Assignments for Parallel Interface
Pin No.
Signal Name I/O* Description
1
STROBE I
The STROBE pulse is used to read data from the host
computer. Pulse width must be 0.5
µ
s or more. Normally, it
is HIGH, and data is latched with the rising edge of this
signal.
2-9
DATA 1-8 I
DATA 1-8 are parallel data bits. When one of these signals is
HIGH, the data bit is 1; when LOW, the data bit is 0. The most
significant bit (MSB) is DATA 8. The signal state must be
maintained for 0.5
µ
s on either side of the STROBE signal’s
active edge.
10
ACKNLG O
ACKNLG is an acknowledge pulse with a width of
approximately 10
µ
s. This signal goes LOW upon
completion of data reception to indicate that the printer is
ready to receive further data.
11
BUSY O
The BUSY signal informs the host computer of the printer’s
status. When this signal is HIGH, the printer cannot accept any
more data.
12
PE O
This signal indicates whether paper is available in the printer or
not. A HIGH level indicates no paper.
13
SLCT O Pulled up to +5 V through a 1.0 K
Ω
resistor in the printer.
14
AFXT I
If this signal is set to LOW, the printer automatically performs
one line feed upon receipt of a CR (carriage return) code. The
status of this signal is checked only at power on and
initialization.
31
INIT I
If this signal goes LOW, the printer is initialized. The pulse
width of this signal must be 50
µ
s or more.
32
ERROR O
This signal goes LOW if the printer has a fatal error or runs out
of paper.
35
+5 V — Pulled up to +5 V through 1.0 K
Ω
resistor in the printer.
17
CHASSIS — Chassis ground.
16
GND — Signal ground.
19-30
— — —
33,36
— — Not used.
15,18,34
— — —
* The I/O column indicates the direction of the signal as viewed from the printer.
Product Description Stylus Pro Service Manual
1-10 Rev.B