905U-L Wireless I/O Installation Manual
905U-L Wireless I/O
Page 23 of 40
Version 1.9
Digital inputs
The 905U-L-T module provides two digital inputs suitable for:
Voltage free contacts
– e.g. mechanical switches; or
NPN transistor devices
– e.g. electronic proximity switches; or
0-5V signals
- 2V
– 4V Minimum range.
Note
PNP transistor devices are not suitable.
The unit provides contact wetting current of approximately 5mA to maintain reliable
operation of driving relays.
Each digital input is connected between the appropriate
Digital Input
terminal and
Ground
.
Each digital input circuit includes a LED indicator that lights when the digital input is active
(i.e. when the input circuit is closed).
To activate the digital input, the switching device resistance must be less than 200 ohms.
Connection
method
Example
Voltage free
contact
Active 0-5v
signal
device
