Dear Sir,

I want to calculate PI tag's standard deviation at selected timestamp according to another tag's value.

For example, supposed that we have two tags, tag1 and tag2. We want to calculate tag1's standard deviation when tag2's value turns from 0 to 1.

Is it possible to make it using current PI AF and Analysis? We can certainly calculate this result and output to new tag.

Thanks.

Hi Shengwen,

try this in analysis...

if 'tag2'>0 then StDev('tag1', '-1d', '*') else NoOutput()

In this case timestamp is from -1d to now.

You can find StDev description in PI System Explorer help...

PI System Explorer 2017 > Asset analytics > Expression functions reference > StDev

Regards,

Igor