LabVIEW Idea Exchange

Problem: Many native VIs use the Non-reentrant execution reentrancy setting.

Solution: The vast majority of native VIs should use the Preallocated clone reentrancy setting.

• The native VIs that need to use Non-reentrant or Shared clone are few and far between - they should be identified on a case-by-case basis. Their Context Help and/or Detailed Help should explain why they need to be set to Non-reentrant or Shared clone.

The following is a selection of vi.lib VIs that should use Preallocated clone. This selection is meant to serve as a starting point and is not comprehensive.

Notes:

• This idea is related to: The reentrancy of new VIs should be "Preallocated clone" . They both argue in favour of using the Preallocated clone setting more.
• A significant number of native VIs are already configured to use Preallocated clone, which is great.
• There are curious cases where closely related VIs are set to different reentrancy settings. For example, Color to RGB.vi is rightly using Preallocated clone, while RGB to Color.vi is Non-reentrant. Similarly, Trim Whitespace.vi is rightly Preallocated clone, while Normalize End Of Line.vi - which lives next to it on the String palette - is Non-reentrant.
  • This suggest that the reentrancy setting of some native VIs was chosen haphazardly. This needs to be rectified.
• The fact that so many native VIs are non-reentrant partly defeats LabVIEW's remarkable ability to create parallel code easily. Loops that are supposed to be parallel and independent are in fact dependent on each other when they use multiple instances of these non-reentrant native VIs. When an application uses multiple instances of these native VIs it is as if there are "hidden semaphores" that are added between the various call locations that call these native VIs. This leads to less performant applications (more CPU cycles, longer execution time, larger EXE compiled code size).

Since the call library function node (3) supports wild-cards it is not clear which DLL file is physically used during runtime. Nevertheless this information can be interesting and important in some cases. Currently there is no way to get this information (1). Therefore I suggest to show the DLL-Path-Output always (2). It shall return the entire path and name of the currently loaded DLL.

Control and indicator references are currently 19 pixels tall. They should be 16 pixels tall. References would then align better with other items which are already 16 pixels tall, such as the Bundle By Name and Unbundle By Name nodes.

This idea is inspired by this idea and this idea.

After working with text-based languages recently, I've become more aware of a very painful flaw in the LabVIEW IDE.

First of all, as software engineer, I like to perform experiments. Make a small change, test it. If it doesn't work, then just use Git to roll back the changes. I've been doing this for years, and with LabVIEW it has been fairly painful. Until recently I didn't realize there was a better way.

Why is it painful? Everytime I use Git to check out a different branch or roll things back, I am forced to close LabVIEW or at least close the project so that LabVIEW detects and loads the new code from disk instead of whatever it has in memory. I lived with that for years because I didn't know any better.

Enter text-based programming and IDEs: VSCode, PyCharm, probably any other modern IDE. I try an experiment, it doesn't work. I roll the changes back in Git and guess what? I don't have to open and close anything! The IDE just automatically detects the file has changed and loads the new file!

When is LabVIEW going to get with the times?

This is an idea I've been working on for a while. It's time to let others start evaluating it. 🙂

 ^ I included the above for Dmitry Sagatelyan and similar folks who have asked me for these things over the years so they know the mindset to use when evaluating the idea. But it's written up below for LabVIEW users who only know LabVIEW as it stands today (Q3 2024).

Feedback and questions welcome. 

A number of people, myself included, have found it necessary to parse ISO-8601 time strings into time values. The ISO standard has a lot of options, so a complete solution is pretty time-consuming. It would be nice if the string parsing functions in LabVIEW included a format specifier that allowed parsing of ISO-8601 time strings directly.

Since a few years, we have native support for Map and Set in LabVIEW.

How about adding a DataFrame type similar to other programming languages (possible even with a native interaction with Python)?

A DataFrame type would be a 2D value where columns can have different datatypes. Currently, one needs to build around this by creating an 1D array of a cluster (or class) type.

Access to the data would be with numerical indexing for the rows and field access (like in a cluster) for the columns.

KR, Benjamin

The connector pane is a very useful feature for defining what the parameters for the VI are, therefore how it interacts with its environment.

On the other hand, the development experience did not age well. The 32x32 icon that is divided into smaller areas based on the pattern selected for the VI feel small on today's screens. On top of that most of the functionality is hidden behind the context menu.

This feels like a lacking experience for a crucial feature, but we grow accustomed to it, there we do not complain. But that doesn't mean things cannot be improved.

I would personally prefer a new window being opened when I want to edit the connector pane. The pane itself could be represented with 5x magnification (or even better, user selectable): 160x160 pixels.

On the pane, we could have a dedicated drop down that facilitates the selection of the pattern.

On each connector we could have a border representing its current state: Dynamic dispatch/Required/Recommended/Optional.

Cycling trough these states would be available on left click, for example, and reversing the direction with a shortcut, like ALT + left click.

Connecting the front panel terminals to the connector pane could be done by dragging and dropping to the desired place. To make sure that mistakes do not happen, the drag operations shall not move the front panel controls on the panel itself.

To make the workflow as smooth as possible buttons could be added to Apply the new connector pane, Apply and reorganize the front panel, Reorganize the front panel or Cancel the whole operation.

To make sure that we don't lose existing functionality the CTRL + left click shortcut shall keep the swap terminals functionality (a.k.a.: switcheroo).

Removing controls from the connector pane could be done by the right click, or left click for selecting the terminal and then using the Delete button on the keyboard.

Other operations inside the context menu, like the rotate by 90 degrees, add terminal, remove terminal, etc. could be made available via the menu of the window. I personally use these less, but if there is need for them, then we can discuss how they shall be presented on the window.

Since this idea was formulating over a long period of time in my head, but by no means lot of tought put into it, I'm very open to discuss the details. And, by no means the only or best solution to improve the Connector Pane UX.

When adding a file via the project tree to a .lvlib or .lvclass, it is highly likely that the file is located in the same folder as the corresponding .lvclass. For .lvlib, the file is either in the same folder or one level deeper.

When using the right-click menu Add File... on a .lvclass or .lvlib, the Select File to Open dialog should automatically navigate to the folder containing the .lvclass or .lvlib.

Currently, it navigates to the previously used folder instead.

This should immediately navigate to the folder containing Cell.lvclass.