RsLogix 500 Training - What do input filters on an Allen Bradley Micrologix PLC do and what happens when they are too high

The input filters on an Allen Bradley Micrologix PLC are normally used to prevent inputs from chattering and to keep electrical noise from giving false readings. 

High speed applications such as encoders put out high frequency pulses very similar to what these filters are meant to cancel out.  If the filters are set too high, they will prevent the high speed counter function file from accumulating values.

The input filters on the Allen Bradley Micrologix PLC are set too high by default for high speed counting applications to work properly.  In this video  we show you how to properly set your PLC input filters and why you lose counts when the filters are set too high.

Next Steps

Go to the Allen Bradley RsLogix 500 PLC Training PLC Training Getting Started Lesson series to select your next lesson.  There are also many other Lesson Series on PLC Programming and Industrial Automation.

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