Parallel Interface (Reverse Channel) - Epson Stylus C40UX Service Manual

Stylus C40UX/C40SX/C20UX/C20SX
Signal Name
Pin No. GND pin In/Out
Return
17 Chassis GND -
16, 33
GND -
19-30
15, 34 NC -
* In/Out refers to the direction of signal flow from the printer's point of view.

1.4.3 Parallel Interface (Reverse Channel)

Transmission mode
Adaptable connector
Synchronization
Handshaking
Data trans. timing
Signal level
Connector pin assignment and signals :
ReturnG
Pin No. Signal Name
ND Pin
1 HostClk 19
PRODUCT DESCRIPTION
Functional description
- Chassis GND.
- Signal GND.
- Not connected.
: IEEE-1284 nibble mode
: See forward channel
: Refer to the IEEE-1284 specification
: Refer to the IEEE-1284 specification
: Refer to the IEEE-1284 specification
: IEEE-1284 level 1 device
See forward channel
In/
Functional description
Out*
In Host clock signal.
Pin No. Signal Name
2 DATA0
3 DATA1
4 DATA2
5 DATA3
6 DATA4
7 DATA5
8 DATA6
9 DATA7
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
35 +5V
17 Chassis GND
16, 33
GND
19-30
15, 34 NC
* In/Out refers to the direction of signal flow from the printer's point of view.
INTERFACE
ReturnG In/
Functional description
ND Pin Out*
20 In The DATA0 through DATA7 signals
represent data bits 0 to 7, respectively.
21 In
Each signal is at high level when data is
logical 1 and low level when data is logical 0.
22 In
These signals are used to transfer the 1284
23 In
extensibility request values to the printer.
24 In
25 In
26 In
27 In
28 Out Printer clock signal.
Printer busy signal and reverse channel
29 Out
transfer data bit 3 or 7.
Acknowledge data request signal and reverse
28 Out
channel transfer data bit 2 or 6.
X-flag signal and reverse channel transfer
28 Out
data bit 1 or 5.
30 In Host busy signal.
30 In Not used.
Data available signal and reverse channel
29 Out
transfer data bit 0 or 4.
30 In 1284 active signal.
- Out Pulled up to +5 V via 3.9 K ohm resistor.
- Out Pulled up to +5 V via 3.3 K ohm resistor.
- - Chassis GND.
- - Signal GND.
- - Not connected.
Revision B
15