Table of Contents
Advertisement
3. External Connection
Connecting Input Signals
Input Circuit
Board
Vcc
PolySwitch
10k Ω
3.3V
SN74LVT245B
GND
* I-xx represents an input pin.
One polyswitch is connected for Vcc(+5V) terminal.
Figure 3.5. Input Circuit < DIO-1616T-PE >, < DI-32T-PE >
The input circuit of interface is illustrated in Figure 3.5.
External digital signals given to signal inputs are TTL levels. The individual input signals are passed
to the personal computer as negative logic signals. As each of the signal inputs is pulled up internally,
the output of a relay contact or semiconductor switch can be connected directly between the signal input
and the signal common pin.
Connecting a Switch
I-00 (CN1 : 2 pin)
GND (CN1 : 1 pin)
When the switch is ON, the corresponding bit contains 1.
When the switch is OFF, by contrast, the bit contains 0.
Figure 3.6. An Example to use Input I-00 < DIO-1616T-PE >, < DI-32T-PE >
40
External device
+5V output
Input pin
Signal
common
Switch
Vcc
GND
DIO-1616T-PE, DI-32T-PE, DO-32T-PE
Advertisement
Table of Contents
