Parallel Interface (Reverse Channel) - Epson Stylus COLOR 800 Service Manual

EPSON Stylus &2/25 800

1.5.2 Parallel Interface (Reverse Channel)

‰Transmission Mode
‰Adaptable Connector
‰Synchronization
‰Handshaking
‰Data Transmission Timing
‰Signal Level
‰Extensibility Request
The printer accepts a request when the extensibility request value is 00H or 04H. The description of
each value is as follows:
ƒ 00H Request nibble mode reverse channel transfer
ƒ 04H Request to return Device ID using nibble mode reverse channel transfer.
Device ID
The printer sends following device ID string upon request:
[00H] [43H]
MFG
CMD
MDL
CLS
Note: [00H] denotes a hexadecimal value of zero.
Table 1-18 shows pin assignments and signals for the parallel interface reverse channel.
Table 1-17. Connector Pin Assignments and Signals (Reverse Channel)
Pin No. Signal Name
1 HostClk
2-9 DATA 0-7
10 PtrClk
11 PtrBusy/
Data bits 3,7
12 AckDataReq/
Data Bits 2,6
13 Xflag/Data bits 1, 5
14 Host Busy
31 /INIT
32 /Data Avail/
Data Bit 0,4
36 1284-Active
18 Logic-H
35 +5V
17 Chassis GND
16, 33, 19-30 GND
15, 34 NC
Note: 1. The symbol / at the beginning of a signal means active LOW.
2. The I/O column indicates the direction of the signal as viewed from the printer.
1-16
IEEE-1284 nibble mode
Same as the forward channel
Refer to the IEEE-1284 specification
Refer to the IEEE-1284 specification
Refer to the IEEE-1284 specification
IEEE-1284 level 1 device (See forward channel.)
EPSON
ESCPL2E, PRPXL, BDC
STYLUS[SP]COLOR[SP]800
PRINTER
Return
GND Pin
19
20-27
28
29
28
28
30
30
29
30
—
—
—
—
—
I/O Description
I Clock signal from the host computer.
I These signals represent parallel data on bits
2 to 9. Each signal is HIGH when the data is
logical 1 and LOW when the data is logical 0.
O Clock signal from the printer
O Busy signal from the printer. Data bits 3 or 7
in reverse channel.
O Acknowledge request signal. Data bits 2 or 6
in reverse channel.
O X flag signal. Data bits 1 or 5 in reverse
channel.
I Busy signal from the host computer
I Not used
O Data available signal. Data bits 0 or 4 in
reverse channel.
I 1284 active signal.
O Pulled up to +5 V via 3.9K-ohm resistor.
O Pulled up to +5 V via 3.3K-ohm resistor.
— Chassis ground for the printer.
— Signal ground.
— Not connected.
Rev. A