Epson Stylus C40UX, Service Manual

Page: 15 / 125

Stylus C40UX/C40SX/C20UX/C20SX Revision B
PRODUCT DESCRIPTION INTERFACE 15
* 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 : IEEE-1284 nibble mode
Adaptable connector : See forward channel
Synchronization : Refer to the IEEE-1284 specification
Handshaking : Refer to the IEEE-1284 specification
Data trans. timing : Refer to the IEEE-1284 specification
Signal level : IEEE-1284 level 1 device
See forward channel
Connector pin assignment and signals :
* In/Out refers to the direction of signal flow from the printer's point of view.
17 Chassis GND - - Chassis GND.
16, 33
19-30
GND - - Signal GND.
15, 34 NC - - Not connected.
Pin No. Signal Name
ReturnG
ND Pin
In/
Out*
Functional description
1 HostClk 19 In Host clock signal.
Pin No.
Signal Name
Return
GND pin In/Out Functional description
2 DATA0 20 In The DATA0 through DATA7 signals
represent data bits 0 to 7, respectively.
Each signal is at high level when data is
logical 1 and low level when data is logical 0.
These signals are used to transfer the 1284
extensibility request values to the printer.
3 DATA1 21 In
4 DATA2 22 In
5 DATA3 23 In
6 DATA4 24 In
7 DATA5 25 In
8 DATA6 26 In
9 DATA7 27 In
10 PtrClk 28 Out Printer clock signal.
11
PtrBusy /
DataBit-3,7
29 Out
Printer busy signal and reverse channel
transfer data bit 3 or 7.
12
AckDataReq /
DataBit-2,6
28 Out
Acknowledge data request signal and reverse
channel transfer data bit 2 or 6.
13
Xflag /
DataBit-1,5
28 Out
X-flag signal and reverse channel transfer
data bit 1 or 5.
14 HostBusy 30 In Host busy signal.
31 -INIT 30 In Not used.
32
-DataAvail /
DataBit-0,4
29 Out
Data available signal and reverse channel
transfer data bit 0 or 4.
36 1284-Active 30 In 1284 active signal.
18 Logic-H - Out Pulled up to +5 V via 3.9 K ohm resistor.
35 +5V - Out Pulled up to +5 V via 3.3 K ohm resistor.
17 Chassis GND - - Chassis GND.
16, 33
19-30
GND - - Signal GND.
15, 34 NC - - Not connected.
Pin No. Signal Name
ReturnG
ND Pin
In/
Out*
Functional description