Function SetAxisScalingMode Causing Stack Fault

[Michelle]

I have an application in which SetAxisScalingMode causes a stack fault error. I've distilled the behavior down into a source file 54 lines long (only 9 lines of "real" code), and a .UIR file with a simple panel that contains a simple graph. I see absolutely nothing in the code that should be causing the crash, so I'm beginning to suspect a CVI bug. I won't make that claim for certain until someone else reviews the attached source code, because heaven knows I've missed the obvious before 🙂

Please, someone, download and unzipped the attached source, and see if you get the same result. At the top of the .c file is a comment block explaining exactly how to reproduce what I'm seeing, and it's REALLY easy.

I'm r
unning LabWindows/CVI under Windows 2000.

I will be on vacation until June 16, and will not be checking email or the disussion forum until then.

Thanks for any help,
-Michelle

[LuisG]

Yes, there is a known bug in CVI 7.0 that would cause this. The workaround is to turn off autoscaling for the top x-axis. For more information see this post:

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=5065000000080000006DD00000&USEARCHCONTEXT_CATEGORY_0=_318_&USEARCHCONTEXT_CATEGORY_S=0&UCATEGORY_0=_318_&UCATEGORY_S=0

Luis
NI

[Michelle]

Much obliged, LuisG!

-Michelle

[Free2mind]

I'm using LabWindows 5.5 and I also have this problem. I follow the link suggested by LuisG but the target doesn't exist anymore. Could you please fix this, LuisG?

[Free2mind]

I would like to precise the problem: The "Stack overflow error" may happen
1. when I try to change the XAXIS range and
2. when I use the option VAL_AUTO for the LEFT_YAXIS
All the UIR then disappears.

[LuisG]

The fixed link to that thread is here but it's probably not going to help you, since that thread is referring to a problem that existed in CVI 7.0, whereas you're using CVI 5.5.

Can you tell us more about the problem you're having? I assume that you've run into a "stack overflow" error. Is it also taking place inside a call to a graph plotting function or does it happen at some other time? Can you reproduce this problem every time?

You also mentioned that the UIR disappears when you change the x-axis range or you enable autoscaling on the y-axis. Can you be more specific with the exact actions that you performed, and what the effect really is? For example, are you making these changes programmatically, or in the user interface editor? If they're being made programmatically, can you post some of the code you're using here?

Thanks

Luis

[Free2mind]

This happens when I change the range (the limits) of the x-axis in the UIR (not in the code). I'm not sure if I can reproduce this any time, but it's quite often (more than half the times).
I have to do scans over a range of x-axis. When I said "the UIR disappears" I mean it quits (without any word but "overflow stack error") very often when I change the limits.
If I don't change the limits of x-axis, this is not going to happen.

[LuisG]

I don't think this is a known problem in CVI 5.5. It might be some bug that is only occurring with your specific .UIR file. Would it be possible for you to attach your .UIR here, so that I can try to reproduce the problem? Even if it doesn't happen every time, as long as I can get it to happen once or twice, I should be able to investigate further.

Luis

[Free2mind]

The problem seems to be resolved after that I have downloaded and installed the latest Run-time engine (Version 8.5). I haven't get any crack so far.
What do you think about this, Luis?

[LuisG]

Without being able to reproduce it here, I have no idea. My guess is that it was some bug that happened to have been fixed some time between 5.5 and 8.5.

Luis