USB-AD-OEM
Page 6
4.1.1
Connecting an Optocoupler
Optocouplers provide optimum protection at each input
line. With them, it is possible to connect higher voltages
and to protect the hardware from being destroyed.
In this regard, please also see application examples of
the optocoupler you use.
Optocoupler cards (ID:OR8) featuring 8 inputs are available
at bmcm.
4.1.2
Connecting a Push-Button / Switch
Please make sure to use a push-button with debounce
protection, because otherwise several pulses might be
recorded.
The 3.9k
W
pull-down resistor is optional in order to
create a defined low signal even with long lines.
4.1.3
Connecting a Voltage Divider
If connecting a DC voltage higher than 5V, a voltage
divider must be used so that 5V at the maximum are
applied at the device input. Exceeding the 5V input
voltage might cause damages to the device.
The relation between the two resistors to be used is
calculated with the following formula:
U/U
1
= (R
1
+R
2
)/R
1
Input voltages less than 5V are also sufficient (
high
³
3V).
