JamesMc86
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Everything posted by JamesMc86
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What you are witnessing is a race condition specific to the way the implicit write text file works. I thought it was odd you get an empty string when it fails - the file should never be empty as you would expect to be overwriting the existing data. This VI works though. My guess is internally the implicitly opened write to text file clears the existing contents first. What you are seeing is a race condition between the file being cleared and the new data being written. I also tried it without the close and that still works (but obviously leaks file handles) So I don't think this is the root of your problems.
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Do running VIs with a closed front panel use CPU for UI elements?
JamesMc86 replied to MarkCG's topic in LabVIEW General
I would guess that switch tabs means that everything on that tab is now triggered to be redrawn (which would be inline with rolfk's comments). If you had some large graphs or something similar then reducing the data they are holding may help reduce the spike to an acceptable level. That said the embedded UI is new and has a few... quirks... so if there is nothing big then talking to NI might be worthwhile as it could be a bug. -
I agree with crossrulz given the errors involved (E-12 and E-13). I put a snippet on a blog post which lets you calculate the error for a particular range. https://devs.wiresmithtech.com/blog/floating-point-precision/ (Note these will be smaller since these are the representation errors which will increase through rounding errors in the maths) I expect neither is better - since the dynamic range of both is the same then no option is more or less appropriate for floating point numbers. I would just pick your favourite, safe in the knowledge that your hardware will probably generate errors much higher that 1 pHz! (p.s. I attached the code since I couldn't get the snippet in the post to work) Double Precision Calculator.vi
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Hi Ton, I'm interested in getting an scrypt implementation in LabVIEW and so looking at using your library as a base. It requires the addition of PBKDF2. Are you interested in contributions to this library rather than forking it? If so it would be great to have a version with your test vectors as well and what version you would want to keep it in. Ideal would be a github repo. If not we will crack on and just depend on what you have already. Cheers, James
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Decouple UI and application core - need advice
JamesMc86 replied to candidus's topic in Application Design & Architecture
I like OO - so bear that in mind with my answer! Ideally you don't want your state machine to know how UI updates are done - it doesn't care, it just needs it done. So I would consider creating a UI class or multiple UI classes for the different parts of the UI with update methods which your state machine can call. Inside of their you can use any of the methods and chop and change between them. Within there my temptation would be to queue them as messages or user events to a separate UI loop but once the separation is done it is easy to try different techniques. -
Saving a class with array of waveform reloads corrupted
JamesMc86 replied to A Scottish moose's topic in LabVIEW General
There is a bug with variant attributes with this method on all targets I believe. I've had this issue where the attributes don't get flattened. I've also had other unknown issues with these methods as well so I tend to avoid then and follow smithd's advice - using JSON or similar to have some more control over the process. -
I don't have full examples but I did write a post on what I felt was the approach to learning OOP that helped me: https://devs.wiresmithtech.com/blog/learn-teach-labview-oop/ (More conceptual than technical)
