Yesterday I went to a talk regarding software development with quality assurance for dimensional consistency. The talk was aimed at developers using Fortran to create predictive model of physical processes. This prompted me to review how LabVIEW treated units and conversions. To my pleasant surprise it handles units and conversions very well. It even handled mixed system (adding or multiplying inches with metres).
The problem that I did find was using a unit value with "_expression_ node" primitive. That is, when I wired a numeric control with a defined unit (in this case "m") to an _expression_ node, I get a bad wire connection with the associated error "You have connected numeric data types that have incompatible units". Same problem when I tried with and "formula node". I checked the Labview help file but the issue is not addressed.
Is this a fundamental limitation of the _expression_ and formula node or is there a way to use these primitive with variable with units.
Paul A. Rochefort
IMD branch
AECL
Chalk River Laboratories
