Interface Specification; Ieee-1284 Parallel I/F (Forward Channel); Ieee-1284 Parallel I/F (Reverse Channel) - Epson Stylus Photo 720 Service Manual

EPSON Stylus Photo 720 / EPSON Stylus Photo EX3

1.3 Interface Specification

This printer has IEEE-1284 parallel interface and USB interface as standard.

1.3.1 IEEE-1284 Parallel I/F (Forward Channel)

Forward channel is the mode to transfer the ordinary printing command to the printer
side from the PC side.
Table 1-3. Parallel I/F Specification (F-Channel)
Item
Transmission mode 8bit parallel
Synchronization By STROBE pulse supplied from the external
Handshaking By BUSY and ACKNLG signal
Signal Level TTL level (IEEE-1284-Level 1 device)
Adaptable connector 36 pin 57-30360 (amphenol) or equivalent
NOTE: I/F cable is recommended to be in minimum length.
The connector pin assignment is described below. For these signals described in the
table, use the twist pair wire and connect the return side to the signal GND.
Table 1-4. Connector Pin Assignment and Signals (F-Channel)
Return Signal
Pin No.
GND Pin Name
1 19 -STROBE
2-9 20-27 Data0-7
10 28 -ACKNLG Printer
Product Description
Specification
From Function Description
The strobe pulse for the printer to read data.
Pulse width requires min. 0.5µs (500ns).
PC
High at normal condition. Receives data after
shifting Low.
The DATA 1 through DATA8 signals
PC
represent data bits 1-8, respectively.
A low signal indicates the printer can accept
data. Pulse width is 0.5 (default) or can be set
at 2µs.
Table 1-4. Connector Pin Assignment and Signals (F-Channel)
Return
Pin No.
GND Pin
11 29
12 28
13 28
14 30
31 30
32 29
36 30
18 -
35 -
17 -
16, 33
-
19-30
15, 34 -

1.3.2 IEEE-1284 Parallel I/F (Reverse Channel)

Reverse channel is used to transfer the information data from the printer side to the PC
side.
Interface Specification
Signal
From Function Description
Name
A high signal indicates that the printer cannot
receive data. The signal becomes high under
the condition below;
BUSY Printer
-Receiving data.
-Error.
-Other I/F receiving data.
PE Printer A high signal indicates paper-out error.
Always at high level. Pulled up to +5V via
SLCT Printer
1.0KΩ resistor.
-AFXT PC Not used.
The printer is initialized by the width of min.
-INIT PC
50µs Low pulse input.
-ERROR PC A low signal indicates printer error condition.
-SLIN - Not used.
Always at high level. Pulled up to +5V via
Logic H -
3.9KΩ resistor.
Always at high level. Pulled up to +5V via
+5V -
1.0KΩ resistor.
Chassis - Printer chassis GND.
GND - Twist pair return GND.
NC - Not used.
Revision A
13