Epson STYLUS COLOR 480, Service Manual

Page: 22 / 149

EPSON Stylus COLOR 480 Revision B
Product Description Interface Specification 22
1.3.2 IEEE-1284 Parallel I/F (Reverse Channel)
Reverse channel is used to transfer the information data from the printer side to the PC
side.
o
Device ID
The printer sends following device ID string when it is requested.
[00H] [5AH]
MFG: EPSON;
CMD: ESCPL2, BDC, D4;(*1)
MDL: Stylus[SP]COLOR[SP]480;
CLS: PRINTER;
DES: EPSON[SP]Stylus[SP]COLOR[SP]480;
(*1): When the D4 mode (IEEE1284.4) is OFF, printer reply as follows.
CMD: ESCPL2,BDC
NOTE: [00H] denotes a hexadecimal value of zero.
MDL value depends on the EEPROM setting. Refer to Appendix.
The connector pin assignment is described in the table below. For these signals
described in the table, use the twist pair wire and connect the return side to the signal
GND.
Table 1-7. Parallel I/F Specification (R-Channel)
Item Specification
Transmission mode IEEE-1284 nibble mode
Synchronization Comply with the IEEE-1284 specification
Handshaking Comply with the IEEE-1284 specification
Logic Level TTL level (IEEE-1284-Level 1 device)
Data trans. timing Comply with the IEEE-1284 specification
Extensibility request data The printer responds affirmatively when the extensibility request
values are 00H or 04H;
00H: Request Nibble Mode Reverse Channel Transfer.
04H: Request Device ID;
Return Data Using Nibble Mode Reverse Channel Transfer
Table 1-8. Connector Pin Assignment and Signals (F-Channel)
Pin No.
Return
GND Pin
Signal Name From Function Description
1 19 HostClk PC Host clock signal.
2-9 20-27 Data1-8 PC
The DATA 1 through DATA8 signals
represent data bits 1-8 respectively.
10 28 PtrClk Printer Printer clock signal.
11 29
PtrBusy/
DataBit-3,7
Printer
Printer busy signal and reverse channel
transfer data bit 3 or 7.
12 28
AckDataReq/
DataBit-2,6
Printer
Acknowledge data request signal and
reverse channel transfer data bit 2 or 6.
13 28
Xflag/DataBit-
1,5
Printer
X-flag signal and reverse channel
transfer data bit 1 or 5.
14 30 HostBusy PC Host busy signal.
31 30 -INIT PC Not used.
32 29
-DataAvail/
DataBit-0,4
Printer
Data available signal and reverse channel
transfer data bit 0 or 4.
18 - Logic H Printer Pulled up to +5V via 3.9K ohm resistor.
35 - +5V Printer Pulled up to +5V via 3.3 K ohm resistor.
17 - Chassis - Printer chassis GND.
16, 33
19-30
- GND - Signal GND
15, 34 - NC - Not used.
36 30 1284-Active PC 1284 active signal.