Contec DIO-0808L-PCI, User Manual

Page: 37 / 57

3. External Connection
30
DIO-0808L-PCI
Connecting Input Signals
Connect the input signals to a device which can be current-driven, such as a switch or transistor output
device.
The connection requires an external power supply to feed currents.
The board inputs the ON/OFF state of the current-driven device as a digital value.
Input Circuit
External circuit Board
Vcc
Vcc
Plus
common
External
power supply
12 - 24VDC
Opto-coupler
Input pin Switch
Opto-coupler
Input pin Switch
Un-
connected
Un-
connected
* I-xx represents the input pin.
Figure 3.3. Input Circuit
The signal inputs are isolated by opto-couplers (ready to accept current sinking output signals). The
board therefore requires an external power supply to drive the inputs. The power requirement for each
input pin is about 5.1mA at 24VDC (about 2.6mA at 12VDC).
Connecting a Switch
I-00 (CN1 : 2pin)
Input plus common (CN1 : 18pin)
External
power supply
12 - 24VDC
+
-
B
oa
rd
si
d
e
When the switch is ON, the corresponding bit contains 1.
When the switch is OFF, by contrast, the bit contains 0.
Switch
Figure 3.4. An Example to use Input I-00