Why does using HRUS as the Holding Register Designator with a BooleanArray data type result in 32 bit array, not a 16 bit array as expected?

Why is it that when I create an OPC tag (inside a UDT) with Data Type ‘BooleanArray’, using HRUS as the Holding Register Designator in the OPC Item path I get an array of 32 bits, instead of the array of 16 bits that I expected.

Per documentation HRUS is for “Holding Registers with 16 bit unsigned integer conversion.” Using HR (for 16 bit signed Holding Register) instead of HRUS as the Holding Register Designator does result in a 16 bit array. As it is converted to an array, signed vs. unsigned does not have much relevance but for testing I want to be able to flip back and forth between “BooleanArray” and Unsigned “Short”.

I am wondering if this is a bug, or a misunderstanding on my part of what HRUS does.
[Ignition v8.05]


Also (for bonus points)…

  • Is there a good reason why I can’t control the individual column widths (like the value column) in the tag browser?
  • Why is it that the tag properties always truncate the display of the parameterized OPC Item Path, no matter how wide I make the window?
  • What is the best way to provide feedback to the development team? I am really appreciating Ignition in general (especially the ability to export nearly anything to text and manipulate with regex etc.) but there is room for improvement (to make my life better) and I’d like to be part of the feedback loop.
1 Like

In java, there are no true unsigned data types. So any unsigned register must be placed in the next bigger datatype in order to properly represent a large unsigned value. It’s that integer that gets turned into an array.


  1. The columns are are adjustable only at the header, when scrolled to the top. Annoying, yes.

  2. No idea.

  3. This forum is best for generic feedback online. Best overall is to pin the developers in a corner during ICC… (:

Regarding tag editor woes in particular: we’re planning to redesign it pretty significantly, before too long.