LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Strange undo behavior

Hello list,

I have the Tools>Options>Enviornment>Maximum Undo Steps per VI set to 99. If I create a new vi, or open a sub vi of my main vi, I can undo all I want (haven't tried all 99).

But in one of my Main VIs (that has a bunch of subVIs), I only have one undo step. After that, ctrl-z is dead and the Edit Undo pulldown turns grey.

This Main VI has been edited on several PC's (all running LV8.2).  Could this have anything to do with it?

Mike

0 Kudos
Message 1 of 20
(3,307 Views)
The undo list is not related to the fact tht a vi has been edited over a number of different PC's.
 
There are cases where the undo list is cleared (after a save).  And cases where items cannot be undone.  I can't remember specifics, but I have noticed a pattern.
 
I think if you have the configuration set to automatically save before running the vi that it will clear the undo list.  I'll try to pay more attention to the cases and post here (if I can remember) 😉
 
R
0 Kudos
Message 2 of 20
(3,275 Views)
Search the LabVIEW Help for "undo" and you get this:

In some instances, LabVIEW deletes all undo information. VI callers automatically update when the VI changes its front panel. LabVIEW deletes all undo information in caller VIs when you make the following changes:

Change a VI connector pane pattern or change the data type of a control.
Change the appearance of a strict data type, change the data type or strictness, or change a type definition of a custom control.
Change the data type or name of a control in a global VI or add or remove a control to a global VI.


Lynn
Message 3 of 20
(3,271 Views)
Thanks for the list Lynn.
0 Kudos
Message 4 of 20
(3,267 Views)

> This Main VI has been edited on several PC's (all running LV8.2). 
Could this have anything to do with it?

That shouldn't matter. But as soon as you save a vi, there are no more
undo's. The undo steps are not stored, and once you save the nr. of undo's
is 0.

I've noticed that sometimes the undo's are reset after a sub VI changes.
E.g. if a connector pane of a sub VI changes, all callers of the subVI
cannot undo any previous steps. It doesn't always happen, but every now and
then (when it's least convenient) it happens. It's too random to dig into...

Regards,

Wiebe.


0 Kudos
Message 5 of 20
(3,258 Views)

Hello list.

I appreciate the input from all of you.

What I see it that I can drop multiple controls or indicators on the front panel, or drop multiple functions (like +, -, =, or even subVI's) and then immediately try to undo them, I can only undo the last one I dropped. It's the same with wires...I can only undo the last wire I placed or moved, and I can only undo the last thing I deleted.

Mike

0 Kudos
Message 6 of 20
(3,242 Views)
Something must have corrupted something...

What happens when you copy paste everything in a new VI? Or when you save
the VI as a different VI?

Do you have specific nodes in your diagram, like FPGA xnodes, variants, type
defs, strict type defs, etc? What happens if you delete them?

If the VI has been editted on different PC's, are the all the same versions,
or do they differ (e.g. 8.2.1 and 8.2 can open each others VI's, but might
have caused the corruption).

Regards,

Wiebe.


0 Kudos
Message 7 of 20
(3,229 Views)

Wiebe,

Thanks for the reply...

Since I started writing it, passed it off to someone else, and then got it back, I'm not at all sure what the other guy (a college kid new to LV) may have done to it.

If I copy it to a new file name, it still has the problem.

If I copy and paste it to a new vi, it still has the same problem.

All of the LV versions are the same...installed from the same CDs.

All of the source VIs are stored on the company network, so the project and all of the VIs get loaded from the same place.

I can live with it...because I don't make many mistakes so I don't need the undo that often (HAHA)...but it's bugging me.

Mike

0 Kudos
Message 8 of 20
(3,217 Views)
The exact same thing started happening to me yesterday, I can only undo one step, regardless of what that step is (like you were saying, even moving wires). I can't figure it out, and it's driving me nuts!
0 Kudos
Message 9 of 20
(3,148 Views)
You can always try if deleting the ini file helps. (If you make a backup
first, you can copy paste stuff back untill the problem reoccurs. Remember
to close LabVIEW before saving the ini file, or LV will overwrite your
changes).

Regards,

Wiebe.


0 Kudos
Message 10 of 20
(3,124 Views)