Epson DFX-8500 Service Manual page 28

DFX-8500
‰
Signal Level:
Parameter
VOH*
VOL*
IOH*
IOL*
CO
VIH
VIL
IIH
IIL
CI
Note: * A low logic level on the logical high signal is 2.0 V or less when the printer is powered off.
And this signal is equal or exceeding 3. 0 V when the printer is powered on. The receiver
shall provide an impedance equivalent to 7.5 K ohms to ground.
‰Connector pin assignments and signals:
Table 1-10. Signal and Connector Pin Assignment (Forward channel)
Pin No. Signal Name
1 /STROBE
2-9 DATA 0-7
10 /ACKNLG
11 BUSY
12 PE
13 SLCT
14 /AFXT
31 /INIT
32 /ERROR
36 /SLIN
18 Logic H
35 +5V
17 Chassis GND
16,33,19,30 GND
15,34 NC
Note: * In/Out refers to the direction of signal flow from the printer's point of view.
1-20
TTL-level compatible, IEEE-1284 level 1 device
Refer to Table 1-9.
Table 1-9. Signal Level
Minimum
-
-0.5 V
-
-
-
-
0.8 V
-
-
-
Refer to Table 1-10.
Return GND pin In/Out*
19 In
20-27 In
28 Out
29 Out
28 Out
28 Out
30 In
30 In
29 Out
30 In
- Out
- Out
- -
- -
- -
Maximum Condition
5.5 V
-
0.32 mA VOH = 2.4 V
12 mA VOL = 0.4 V
50 pF
2.0 V
-
0.32 mA VIH = 2.4 V
12 mA VIL = 0.8 V
50 pF
Functional Description
The strobe pulse. Read-in of data is performed
at the falling edge of this pulse.
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.
This signal is a negative pulse indicating that
the printer can again accept data.
A high signal indicates that the printer cannot
receive data.
A high signal indicates paper-out error.
Always at high level when the printer is
powered on.
Not used.
The falling edge of a negative pulse or a low
signal on this line causes the printer to initialize.
Minimum 50 us pulse is necessary.
A low signal indicates printer error condition.
Not used.
Pulled up to +5V via 3.9K ohm resistor.
Pulled up to +5V via 3.3K ohm resistor.
Chassis GND.
Signal GND.
Not connected.
Rev. B