Leaderboard

As rule I tend to avoid express VIs, but I happened to click on a link in Christian's signature and found this. I haven't looked at it in detail, but this may be the one express vi I'm willing to use.

About Express VIs in general: There is nothing inherent in Express VIs that requires them to do an init/destroy sequence. However, Express VIs that work with open resources (i.e. the assistants) do have to have some way to open and close those resources, since there aren't explicit open and close operations as you'd get when using a lower level API. Therefore, it all depends on the Express VI, which is a good mantra to remember when thinking about Express VIs. At run time they're really not much different from a subVI, most of the gripes people have with them have to do with the way that certain Express VIs are implemented, not with the technology itself. About the Specific Error Handler: The nice thing about having one as a reference library is that its open source. If you don't like what it does, then change it . Or better yet, post me a comment in the attached discussion forum so that I can make it what people want it to be . The Specific Error Handler does not need any initialization or cleanup. Most of the processing of the error configuration is done when you hit OK from the configuration dialog, not at run time. At run time, it stores a fairly simple list of errrors and actions, the only performance hiccup will be that it does have to do a search in the event of an error. At the moment, I haven't done a whole lot to optimize the search, since I don't expect individual instances of the VI to have more than a dozen or so errors handled, but if anyone starts using larger lists in and individual instance, I'd be interested to know about it and I can consider doing some more optimization. Regards, Ryan K. NI Systems Engineer

I presented at NI-Week 2009 on a couple of paradigms for extending the LabVIEW Error Handling Core (as inspired by all your posting here). Here are the resources from that presentation (I didn't screencapture the examples, but you should be able to see what I was talking about from the video and the code that's included): NIWeek Session Video Presentation Slides.pdf Presentation Code.zip It's a hot topic, and I know a lot of people have strong opinions on it, so let's discuss!

> Dropping a Variant Collection object on a VI creates a Variant > Collection with a CollectionImp object instead of one of the > childclass objects. Go to Variant Collection.lvclass:Variant Collection.ctl. Change the default value (not the type, just the value) of the CollectionImp control to be an instance of one of the concrete types -- HashTable, for example. Now whenever you drop VariantCollection.lvclass, you get one that has a hashtable unless/until you change it to something else.

I agree. My main issue with them is typically they don't do quite what I want or don't give me quite the control I'm looking for. Can you explain this a bit? Is the init-destroy sequence executed each time during runtime or each time you drop an express vi on a block diagram?

Your comments got me to look closer at my simulated data. I knew my real data would be noisier, but it will also look more like a sine wave than the triangle wave I had. I bumped up the sample frequency and now it looks better. Sorry to say though that the contributed ideas won't work on the new data. I'm back to my original plan of finding peaks and differentiating. By finding the time between peaks in the differentiation I can get the gaps. OK anybody up for round 2? George Fing gaps 2.vi

While we're being creative, here's another way to do it. Again, it works for this particular sim data. Not sure it's any more efficient than the diff method though. Curious to see your approach.

Hi dblk22vball You can easily add scales in MAX, they appear as per below: You can edit them whilst the global channel is running, but you have to stop and restart for the change to take effect.