Tag History - Range Aggregation Mode Function

Ignition
1

Hey folks,

My understanding of the ‘range’ aggregation mode is that it will return the range between the greatest and smallest value in a given time range.

However, I have several tags that are frequently static and the range will report the static value rather than a 0 (no change). Is this how range is intended to work? Is there a work around to report a 0 on no change?

(The conditions under which I am experiencing this is with realtime data from the previous minute in a power table, fixed sampled size of 1 at a 10 second polling rate. Tag has been static for 5+ minutes)

Many thanks!

2

I wonder if you have enough historical points in the sampling period. What are the history settings on the tag?

3

Hey Matt,

The tag is running at the Default Historical with a historical deadband of 1.0, historical deadband is absolute, and the value is analog.

With the deadband being set to 1, if there isn’t any change then there is no value being written, resulting in not enough samples?

Thanks for the pointer, I hadn’t considered that.