Indirect Tag History Binding Expression

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I think there's two fundamental things that you're missing, one of which is (in my opinion) really, really bad UX on our part.

  1. The 'Expression' mode for a tag history binding expects you to author an expression that returns a well formatted tag history configuration object. Since you currently cannot [1] create arbitrary array and object literals in expressions, your tag history binding expression must point to some other custom property literal. There's literally no other way to use expression mode.

  2. You must specify an aggregation function when working with our historian. The historian always uses some kind of compression when storing literal values [2]. The aggregation mode used in your tag history binding is either the 'Query Mode' you specify in the dropdown at the top, or the aggregation function defined per tag. If you don't want to specify an aggregation mode, just omit the key in the object you're returning via the expression. Fair play - I didn't know that it was possible to do that until I dug into the code just now.

  1. without custom modules, see @pturmel's Integration Toolkit module ↩︎

  2. ↩︎

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