Epson EPL-9000, Service Manual

Page: 24 / 162

Service Manual
General Description
1.3.1.2
Reverse Mode
The reverse mode for supports the nibble mode of This printer can run in
reverse mode, in which the printer can inform the computer of its status by EJL and PJL
commands.
System:
nibble
Connector type:
receptacle
Applicable plug: 57-30360 or equivalent)
Signal description: See Table 1-9.
Table 1-9. Parallel Interface Pin Assignments
Pin No. Signal Name
Description
1 STROBE
IN
This signal is a strobe pulse used to read extension
request values from the host computer during negotiation.
The signals are data
bits of extension request values during
2-9 DATA
1-8
IN
negotiation.
This printer supports following values:
0000 0100: Request Device ID (by nibble mode sending)
0000 0000: Request nibble mode
10
ACKNLG
OUT Printer data sending clock.
11 BUSY
Printer sending data bits 3 and 7 during data transfer
to host computer.
12 PE
Printer sending data bits 2 and 6 during data
transfer to host computer.
13
Printer sending data bits 2 and 6 during data transfer to
host computer.
HostBusy: This signal informs the printer of the host computer
14 AUTO-FEED
IN
state. When the signal is HIGH, the host computer cannot
accept data.
NC
Not used.
16
Logic ground level.
17 CHASSIS -
Connected to the printer chassis. The printer chassis
and the signal are connected to each other.
18 NC Not connected.
19-30
.
Ground level for the twisted pair return signal.
31 INIT
IN High level fixed
32
ERROR
Printer sending data bits O and 4 during data
transfer to host computer.
33
.
Same as for pins19 to 30.
34 NC
Not
35
+5
Pulled up to through 1.0 Kohm resistance.
36 IN
1284Active: If this signal is set to HIGH, this printer active
(reverse mode).
Rev.
1-13