User's Manual

Elpro Technologies 450U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 1.4.0 www.cooperbussmann.com/wirelessresources 17
Digital Input
When used supports voltage free contact connection such as a mechanical switch or a
NPN transistor device such as an electronic proximity switches.
Contact wetting current of the input is approximately 5mA and is provided to maintain reliable operation for driving relays.
The digital input is activated by connecting between the "IO" and M" terminals.
When activating the input the I/O indication on the front panel of the module will be lit GREEN when
the input is switched on (closed/shorted). Provided the resistance of the switching device is less than
200 ohms, the device will be able to activate the digital input.
PNP transistor devices are not suitable.
Figure 20- DIO Input (Switch)
Figure 19 - Digital Input (Transistor)