Epson EPL-N1200, Service Manual

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1.3.1.2 Nibble (Reverse), ECP Mode
The reverse mode for EPL-N1200 supports the IEEE-P1284 nibble mode. 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 mode of IEEE-P1284
Connector type: P90-25027-1 (Amphenol) receptacle
Applicable plug: 57-30360( Amphenol or equivalent)
Signal description: See Table 1-9.
Table 1-9. Parallel Interface Pin Assignment
Pin No. Signal Name I/O Description
1 STROBE IN
HostClk: This signal is a strobe pulse used to read extension
request values from the host computer during negotiation.
2-9 DATA 1-8 IN
The signals are data bits of extension request values during
negotiation. This printer supports following values:
0000 0100: Request Device ID (by nibble mode sending)
0000 0000: Request nibble mode
10 ACKNLG OUT PtrClk: Printer data sending clock.
11 BUSY OUT
PtrBusy: Printer sending data bits 3 and 7 during data transfer
to host computer.
12 PE OUT
AckDataReq: Printer sending data bits 2 and 6 during data
transfer to host computer.
13 SLCT OUT
Xflag: Printer sending data bits 2 and 6 during data transfer to
host computer.
14 AUTO-FEED IN
HostBusy: This signal informs the printer of the host computer
state. When the signal is HIGH, the host computer cannot
accept data.
15 NC -
Not used.
16 GND - Logic ground level.
17 CHASSIS GND -
Connected to the printer chassis. The printer chassis GND
and the signal GND are connected to each other.
18 NC - Not connected.
19-30 GND -
Ground level for the twisted pair return signal.
31 INIT IN nInit: High level fixed
32 ERROR OUT
nDataAvail: Printer sending data bits 0 and 4 during data
transfer to host computer.
33 GND - Same as for pins 19 to 30.
34 NC - Not used.
35 +5 - Pulled up to +5V through 1.0 Kohm resistance.
36 SLCT IN IN
1284Active: If this signal is set to HIGH, this printer active
P1284 (reverse mode).
General Description EPL-N1200 Service Manual
1-14 Rev. A