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7.4 Analog Inputs
The analog inputs on certain I3N models allow voltage or current measurement from a variety of devices.
Analog inputs may read 0-20 mA current only or may also read 0-10VDC.
Refer to the datasheet specific
to the I3N model being used.
The analog inputs have a digital filter that can be used to filter electrical noise that may be unavoidable in
some installations. The downside to digital filtering is the inputs will respond more slowly to sudden
changes in the actual input.
For more information on analog input configuration and use, see the chapter on i3 configurator
Configuration.
10.4.1 Common Cause of Analog Input Tranzorb Failure.
If a 4-20mA circuit is initially wired with loop power but without a load, the analog input could see 24VDC.
This is higher than the rating of the Tranzorb.
This can be solved by not connecting loop power prior to load connection or by installing a low-cost PTC in
series between the load and the analog input.
Figure 7.2 – Analog Input Tranzorb - Troubleshooting
7.5 Analog Outputs
The analog outputs on I3N devices may provide only 0-20mA output or may also provide a
0-10VDC output.
Refer to the datasheet specific to the I3N model being used.
When the controller is stopped, the operation of each output is configurable. The outputs can hold the
state they were in before the controller stopped, or they can go to a predetermined value. By default,
analog outputs are set to a value of zero.