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3.3 Alarm Setup
Certain devices support alarm inputs and outputs, check your specific device for alarm capability.
Alarm Input
Refer to Figure 3-3 for alarm input configuration. The device collects that status of the alarm input port
when the input signal is idle or grounded. If the input signal is connected to the 3.3 V or it is idle then
the device receives the alarm input signal. If input signal is grounded, then no alarm input signal is
detected.
Figure 3-3
Alarm Output – Level Application
Use this alarm output configuration if the output triggers an external device by increasing the voltage.
The alarm must increase the external pull-up resistance to trigger (high level) the device. The
maximum external pull-up level is 5 V and the maximum port current is 5 mA. Once the output
increases the pull-up resistance, the alarm decreases the output voltage to the normal state (low level)
at less than 0.8 V.
Figure 3-4
