Reverse Channel Specifications - Epson Stylus COLOR 1520 Service Manual

1.3.1.2 Reverse Channel Specifications

‰Transmission mode
‰Adaptable connector
‰Synchronization
‰Handshaking
‰Data transmission timing
‰Signal level
Table 1-18 shows the connector pin assignment and signals for reverse channel of the parallel interface.
Table 0-18. Connector Pin Assignment 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 /
AckData Bits 2,6
13 Xflag/Data bit 1,5
14 HostBusy
31 /INIT
32 /Data Avail /
Data bits 0,4
36 1284-Active
18 Logic-H
35 +5V
17 Chassis GND
16,33,19-30 GND
15,34 NC
Note) The symbol */* at the beginning of a signal means active low.
‰Extensibility Request
The printer responds affirmatively when the extensibility request values are 00H or 04H, as follows:
‰Device ID
The printer sends following device ID string when it is requested.
Note) [00H] denotes a hexadecimal values of zero.
Rev. A
:IEEE-1284 nibble mode
:Same as for 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 the forward channel specification.
Return I/O
GND Pin
19
20-27
28
29
28
28
30
30
29
30
-
-
-
-
-
00H :Request Nibble Mode Reverse Channel Transfer.
04H :Request Device ID;
Return Data Using Nibble Mode Rev Channel Transfer.
[00H] [xxH]
MFG :EPSON;
CMD :ESCP2E, PRPXL;
MDL :Stylus COLOR 1520;
CLS :PRINTER
Description
I Clock signal from the host computer.
I These signals represent parallel data
information 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 bit 3 or 7 in reverse channel.
O Acknowledge request signal.
Data bit 2 or 6 in reverse channel.
O X flag signal.
Data bit 1 or 5 in reverse channel.
I Busy signal from the host computer
I Not used
O Data available signal.
Data bit 0 or 4 in reverse channel.
I 1284 active signal.
O Pulled up to +5V via 3.9 K ohm resistor.
O Pulled up to +5V via 3.3 K ohm resistor.
- Chassis ground for the printer.
- Signalground.
- Not connected.
Product Description
17