1.3.1.2 Reverse Mode

Reverse mode for the EPL-5500 supports the IEEE-P1284 nibble mode. This printer can run in
reverse mode, in which the printer can inform the computer of its status with EJL and PJL
commands.
System: IEEE-P1284 nibble mode
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
1STROBE 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
These signals are data bits of extension request values received
during negotiation. This printer supports following values:
0000 0100: Request Device ID (sent in nibble mode)
0000 0000: Request nibble mode
10 ACKNLG OUT PtrClk: Printer sends clock data.
11 BUSY OUT PtrBusy: Printer sends data bit s 3 a nd 7 du ring data transf er to
host computer.
12 PE OUT AckDataReq: Printer sends data bits 2 and 6 during data
transfer to host computer.
13 SLCT OUT Xflag: Printer sends data bits 2 and 6 dur ing data transfer to
host computer.
14 AUTO-FEED IN HostBusy: This signal informs the printer of the host computer’s
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 pr inter chassi s. The pri nter chassi s 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: Fixed at HIGH level.
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 +5 V through 1.0K-ohm resistance.
36 SLCT IN IN 1284Active: If this signal is set to HIGH, this printer is actively
in P1284 (reverse mode).
EPL-5500 Service Manual General Description
Rev. B 1-11