Parallel Interface (Reverse Channel) - Epson DFX-8500 Service Manual

Connector pin assignments and signals: See Table 1-12 below.
Table 1-12. Signal and Connector Pin Assignment (Forward channel)
Pin No. Signal Name Return GND pin
1 /STROBE
2-9 DATA 0-7
10 /ACKNLG
11 BUSY
12 PE
13 SLCT
14 /AFXT
31 /INIT
32 /ERROR
36 /SLIN
18 Logic H
35 +5 V
17 Chassis GND
16,33,19,30 GND
15,34 NC
* From the printer's point of view.

PARALLEL INTERFACE (REVERSE CHANNEL)

Data transmission mode:


Connector type:


Synchronization:


Handshaking:


Data transmission timing:


Signal level:


Extensibility request:


Device ID:
I/O*
19 I
20-27 I
28 O
29 O
28 O
28 O
30 I
30 I
29 O
30 I
- O
- O
- -
- -
- -
IEEE-1284 nibble mode
57-30360 (AMPHENOL) 36-pin plug or equivalent
See the IEEE-1284 specification.
See the IEEE-1284 specification.
See the IEEE-1284 specification.
TTL-level compatible, IEEE-1284 level 1 device
When the printer receives the hexadecimal signals 00h or 04h, it
responds in the following manner:
00h: The printer enters reverse channel mode, allowing data to be sent to
the host.
04h: The printer sends the device ID to the host.
[00h][3Ah]
MPG: EPSON;
CMD: ESCP9, PRPII9, BDC;
MDL: DFX-8500;
CLS: PRINTER
PRODUCT DESCRIPTION
Description
The strobe pulse. Reads in data at the falling
edge of this pulse.
The DATA 0 through DATA 7 signals represent
data bits 0 to 7, respectively. Each signal is
HIGH when data is 1 and LOW when data is 0.
This signal is a negative pulse indicating that
the printer can again accept data.
A high signal indicates that the printer cannot
receive data.
A high signal indicates a paper-out error.
Always at high level when the printer is
powered on.
Not used.
The falling edge of a negative pulse or a low
signal on this line causes the printer to
initialize. A minimum 50-µs pulse is necessary.
A low signal indicates a printer error.
Not used.
Pulled up to +5 V via a 3.9 kΩ resistor.
Pulled up to +5 V via a 3.3 kΩ resistor.
Chassis GND.
Signal GND.
Not connected.
1-21