EC-520 User’s Manual
19
～
30
GND
Ground
---
Loop ground that is twisted with signal line.
31 16 /INIT
Initialization of
printer
Input
Low level means initialization of printer
32
/ERROR
Error happens
with printer.
Out
When the printer is in state of paper out, offline
condition or error, this signal level becomes low.
33
GND
Ground
---
Same
with
19
～
30 pins.
34
NC
Empty pin
---
This pin is empty.
35
+5V
+5V supply
Out
Pull up to 5V by the 3.3K
Ω
pull-up resistor.
36
/SLCTIN
Printer is
selected and
answered.
In
Only when this signal level is low, can the data be
put into the printer.
The “direction” in the title panel means the flow direction of printer signal to the printer.
“Return” in the title panel means returning by pair-twist. You must confirm that the interface
cable is pair-twist shielding line, and every signal line is looped with ground line and
pair-twisted together. Shielding line should be connected with the frame ground of host
computer and printer.
All the interface condition is based on TTL level. The rising and falling time of signal must
be less than 0.2 ms.
The data transfer must comply with the specification of ACKING or Busy signal. Only when
the level of ACKING or Busy signal is low can data be transferred.
(4) Time sequence of Parallel to transmit data (as shown by Figure 5-3):
5
μ
s
5
μ
s
0.5
μ
s
0.5
μ
s
0.5
μ
s
/
STR
DAT
/
ACK
BUS
Figure 5-3 Time sequence of Parallel to transmit data
5.2.3 USB Interface
1. The USB interface connector is USB-B type (as shown by Figure 5-4):
Figure 5-4 USB-B type connector
2. The connecting figure of printer and computer with USB interface (as shown in Figure 5-5).
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