How to retrieve selective step data points?

If you're able to create an analysis in AF, it would be easy to create a calculated tag that only returns these yellow points. Then you could pull that tag into Excel and use it. That would be my recommendation!

If you still want to attempt making this in Datalink, I'd look towards the Compressed Data function and try to use a filter. If you know the archive value is always 0 before the desired point, you could add this to the Filter field: PrevVal('YourTag','*')=0

If you're able to create an analysis in AF, it would be easy to create a calculated tag that only returns these yellow points. Then you could pull that tag into Excel and use it. That would be my recommendation!

If you still want to attempt making this in Datalink, I'd look towards the Compressed Data function and try to use a filter. If you know the archive value is always 0 before the desired point, you could add this to the Filter field: PrevVal('YourTag','*')=0

Thank you Asle. I used the filter field provided and this worked great.

Perfect

(Please mark my answer as correct/best, so the system knows this answer has been accepted as the correct one)

Hi Ansle maybe I could trouble you for one more similar question. Let's say I wanted to pull data when the in-between values are not zero, how would I filter these specific points? (like in yellow). Thanks

Hi.

If you can provide a set of rules on how to accomplish picking the yellow points, perhaps it's easier to answer!

Is it so that you just want the first value for every flat line? That could be solved by changing the tag to be stepped, so you just have vertical and horizontal lines. Then you could add a filter that you just want the values which are different than the previous value, f.ex. PrevVal('YourTag','*')<>'YourTag'

Thank you. I have requested IT to look into this tag and they said the stepping was not checked so they did enable it. I'll have to wait and see when we use this tag next time how it registers.

But yes, I'm interested in the first value of the flat lines and pull these into excel with the Pi datalink.

I have a another question regarding this same data trends but to filter out the random zero values in addition to the Prevval filter. I'll post it as a separate question thread though.