Parallel Interface (Reverse Channel) - Epson LX-300 Service Manual

LX-300+

1.3.2 Parallel Interface (Reverse Channel)

Transmission mode: IEEE-1284 nibble mode
Adaptable connector: See 1.3.1 "Parallel Interface (Forward
Channel)"
Synchronization: Refer to the IEEE-1284 specification
Handshaking: Refer to the IEEE-1284 specification
Signal level: IEEE-1284 level 1 device
See 1.3.1 "Parallel Interface (Forward Channel)"
Data transmission timing: Refer to the IEEE-1284 specification
Extensibility request: The printer responds to the extensibility
request affirmatively, when the request is 00H or 004H, which means;
00H: Request for nibble mode of reverse channel transfer
04H: Request device ID in nibble mode of reverse channel transfer
Device ID: The printer sends following device ID string when it is
requested.
When IEEE1284.4 is enabled;
Table 1-13.
[00H][4EH]
MFG: EPSON;
CMD: ESCPL2,PRPXL24,BDC,D4;
MDL: LX-300+;
CLS: PRINTER;
DES: EPSON[SP]LX-300+;
When IEEE1284.4 is disabled;
Table 1-14.
[00H][4BH]
MFG: EPSON;
CMD: ESCPL2,PRPXL24,BDC;
MDL: LX-300+;
CLS: PRINTER;
DES: EPSON[SP]LX-300+;
Product Description
Table 1-15. Connector Pin Assignment and Signals
Pin
Signal Name
No.
1 HostClk
2 DATA1
3 DATA2
4 DATA3
5 DATA4
6 DATA5
7 DATA6
8 DATA7
9 DATA8
10 PtrClk
PtrBusy/
11
DataBit-3,7
AckDataReq/
12
DataBit-2,6
Xflag/
13
DataBit-1,5
14 HostBusy
31 -INIT
-DataAvail/
32
DataBit-0,4
36 1284-Active
18 Logic-H
Interface Specifications
Return
GND In/Out Functional Description
Pin
19 In Host clock signal.
Parallel input data to the printer.
20 In
21 In
22 In
23 In
24 In
25 In
26 In
27 In
28 Out Printer clock signal.
Printer busy signal and reverse
29 Out
channel transfer data bit 3 or 7.
Acknowledge data request signal
28 Out and reverse channel transfer data
bit 2 or 6.
X-flag signal and reverse channel
28 Out
transfer data bit 1 or 5.
30 In Host busy signal.
30 In Not used.
Data available signal and reverse
29 Out
channel transfer data bit 0 or 4.
30 In 1284 active signal.
This line is pulled up to +5V
-- Out
through 3.9 kΩ resister.
Revision A
bit0:LSB
bit1
bit2
bit3
bit4
bit5
bit6
bit7:MSB
21