Change (Analytic Filter)

Description

The Change filter is used to prevent output unless there has been a change to the incoming data.

This prevents redundant calls to your sinks.

The amount of change allowed can be set with the threshold parameter. This allows you to filter out small amounts of drift or error in the value.

Parameters

NameDefaultMeaning
Threshold0The amount of change that can be safely ignored

Example

<filter type="Change">
   <threshold>0.01</threshold>
</filter>

Prevents output unless the value has changed by more than 0.01 (in either direction)

Example Input Sequence
IndexValue
07:00:0010

Output Sent (No Previous Values to Compare Against)

IndexValue
07:10:0010

No Output (No Change Detected)

IndexValue
07:20:0010.01

No Output (Change Does Not Exceed Threshold)

IndexValue
07:30:0011

Output Sent (Change Exceeds Threshold)