I need to make a PI Calculation with 4 boolean tags (need to sum them), I've tried to make it like this:

'Tag1'+'Tag2'+'Tag3'+'Tag4'

But this generetes an error: "**Error Evaluating Tag or Expression**"

The tags are correct, I'm supposing it's because they are boolean, is this correct?

How can I make the sum of those tags with PI Calculation?

Thanks

Can you explain a little more? In PI there are no "Boolean" tags that I know of. If you are using a digital tag you could access the state number using StateNo PE function. If they are strings you could use the new array formulas to obtain the sum. Perhaps the FilterData and the total function together would work. I need some more details to provide better guidance.