Expression addition problem?

This should be SUPER easy, but I can’t figure out whats going wrong. here’s my expression.

tag({Site.SiteName}+"/Recycle_Tank_LVL/Cfg_PVEUMin")+ 9

site.SiteName is a string = “Folder1”

the tag in question is a float = 1.25

so … this should be 1.25 + 9 = 10.25

I’m getting 1.259.

If i remove the “+9” I get 1.25. So it’s finding the tag value, just not adding the 9 correctly?

I’ve tried this a few different ways. If I directly reference the tag, it works. Anything indirect does not.

ok I put the whole thing in toFloat() and that worked, but why is tag() returning a string?

The tag() functions returns a generic object as it can’t known ahead of time what datatype your tag is. For a generic object, concatenation is the default ‘+’ operator. You really should avoid the use of the tag() function – it exists for compatibility with legacy applications. Instead, add a custom property of the appropriate datatype (float or double in this case) and use indirect binding to load the desired tag into that property. Then use that property in the +9 expression and all will work.


ahhh that makes sense. and yeah I was trying to avoid adding another property. Thanks for the detailed explanation!