Xytronix Research & Design ControlByWeb X-16s User Manual page 17

X-16s™ Users Manual
3.5 Dry Contact Switch
The illustration below shows an example of using the X-16s to monitor the status of a gate or door over
an IP network. The status of the device is detected with a simple switch. These type of sensors are
called "dry contacts" in that the device output is a bare switch with no power source. In this example a
voltage source for the switch is provided by the +5Vref output. A pull-down resistor must be provided to
drive the input to a known state (0V) when the switch is open. In this example the measurement voltage
will be 5.0V when the switch is closed and 0-V when the switch is open. A conditional event can be
defined to detect whether the input voltage is above or below a 2.5-V threshold to detect the state of the
switch.
Xytronix Research & Design, Inc.
Example Applications
Page 17