LAVA 1.0 Content

The label of a Formula Node is not associated to it's BD object. While, For, and sequence structures will reposition the label when the associated object is resized on the block diagram. The Formula Node label just 'hangs out' wherever it is placed. In certain cases, the label can even appear to be part of the formula after a resize

I was documenting and refactoring some old code, and noticed that this problem exists.

Minor irritation, checked and this existed in LV 7.1 as well...

That's what I get for touching old code!

Now I read a whole lot and the program can keep up.

There is still a slight gap though.

I would suggest using a parallel loop for the SO Write function, and passing the data from the read/calc loop to the SO Write loop through a queue. I've attached a quickly modified version of youR vi for review.

If your data set is large (or continious) you should place some sort of wait next multiple in the producer (read/calc) loop so you don't eat up all your system memory by producing SO data faster than the output rate.

Also, performance almost always improves when you keep the data types as integer and provide the correct type input to the primative functions. I believe you are writing doubles to the 8 bit mono input of the SO write, after adding a constant of type double to an I8.

Download File:post-949-1153827402.vi

Any ideas how to get rid of this problem? LabVIEW 8 is no solution since 7.1 is still the default environment in this case.

I could not recreate your problem. I made a simple vi that calls the MD5 routine twice, and also loads the md5.vi itself for calculation. I did not receive error code 8.

The only thing I can think of is that some of the high level file I/O functions do not provide an error cluster, and you may be seeing a race condition; the file I/O function is still using the file when the second MD5 function is called, the file I/O function has reserved the file for read/write and the .NET MD5 call is timing out trying to get a file handle.

I assume that you are creating a new file, then calculating an MD5 as a checksum. Try to use the file path out of the write characters to file as the input to the MD5 function to enforce data flow.

Download File:post-949-1153825804.vi

This year LabVIEW has been around for 20 years and still is practically the only graphical programming language on the market. LabVIEW is heavily patented, but the main first patents expire in 2007 which would leave a door open for open standard for graphical programming language. I myself especially would like to see a real object oriented graphical programming language that has been designed for object oriented use right from the beginning.

I think an open standard would benefit everybody, even NI. NI is a pioneer in software data aquistition. Open standard would attract more, maybe even much more, developers to graphical programming languages in general. This would defenitely benefit NI, as it has such a strong foot hold in the graphical programming. NI would propably not loose many of its current customers but would also gain new ones.

Is there a project developing an open standard for graphical programming language? If not, would anybody like to start up such a project.

Hi all,

Does anybody have any idea on how many LabVIEW users are there around the world? Also some geographically more restricted estimates are appreciated.

-jimi-

Found an answer on the ni forum

http://forums.ni.com/ni/board/message?boar...uireLogin=False

Hello, I have a string of hex data in the form of FFFFFFFF that is a hexadecimal represntation of a floating point number based on the IEEE754 standard.

For example 4281C9B5 in the hex string is about 64.89 in decimal.

How do I convert from the hex string to the decimal number

i am lost, have read and searched but do not have an answer.

Any help is apreciated

Welcome to LAVA!

Your question is fair, and lucky for you one of our greatest members has helped in the most recent rewrite of one of the best books called "LabVIEW for Everyone". The original books are good, and with Jim's input on the third edition, you shouldn't be dissapointed.

Another book worth reading is "A Software Egineering Approach to LabVIEW" by Conway and Watts. This book is a couple of years old, but covers software planning and design. Preview of it available via Google The authors are from Hampshire, UK their web site is http://www.ssdc.co.uk/. I took the Intermediate I & II classes, and the concepts as well as small portions of this book were referenced. You should know that there are some rendering quality problems with the illustrations in this book; not the fault of the authors.

The third edition of LabVIEW for Everyone is expected to be released on August 1st. I'm not sure about ordering from the UK, but Amazon is offering a nice discount if you pre-order.

So what is it you want to prevent and how much is it worth to you? If it is about not allowing to run your software by people that would anyhow never buy your software, then honestly every single dollar spent into copy protection is simply lost money. If it is about the fun to have copy protection built into your application, it's the same. Only if you can make a valid case that software will be bought thanks to copy protection can you start to look into spending money for this if you want to think commercial.

Everybody knows that it is very common that comapnies and laboratories buy too few licenses and then create unauthorized copies of the software internally. It's unfair that I have to charge the honest customers extra price to cover the unbought licenses. Every license control system can be cracked, however even the simplest license control system gives users the message that the it is not proper to create unlicensed copies of the software.

There are many issues where license management scheme is a validly applied.

1) Beta testing - You may want to limit your beta testers from using beta stage software after it becomes obsolete.

2) Free download for trial versions - A limited period fully featured license for trial version

3) Alternative pricing models allow users to choose the pricing model that best suits them

- Pay per user

- Pay per computer

- Pay per capacity

- Pay per active use

- Site licenses

- Periodic payments

- Pay per feature

- Superdistribution (peer-to-peer distribution)

So it is not only about copy protection. It is also about giving customers alternatives of the payment schemes. I can attract more customers if I can give light users cheaper or even free licenses at the same time I charge heavy users more. This won't be possible without some kind of license management.

Of course I need to consider if it is worth it. If I am about to write a license management software toolkit, would there be interest among the LabVIEW developer community in this kind of toolkit?

There is a white paper at The Register about license management issues.

the the total VI count, GOBs count, and actual/estimated hours for the complete project

Now I can actually measure the the gobs(1) of LabVIEW code I've written over the years!

Manfred, thankyou for your help, modified the VI to give the checksum as a 2 character hex.

Works well, once again thanks for your help.

Hello,

I have a character string to send to a device over a serial link.

the string is in the following format

$nnRDaaaabbbbzz

The nn is a number from 0 to 99

the aaaa is a number from 0000 to 0016

the bbbb is a number from 0000 to 0016

zz is the checksum in hex, and is generated from exclusive ORing each of the preceding bytes.

Any tips on how I generate this checksum ?

Cheers

Mat

does this mean that mom(or dad) gets exchanged

Exchanged was the idea... My wife and I play this game to try and reduce the crying. Notice that you only get 1000 ms of rest when Happy? = True. Maybe a bit optimistic... :laugh:

See what happens when you code without a software design? Then again, it only took me about 5 minutes, and you could figure it out, right? Gotta LOVE LabVIEW!

Now, about 'designing' your family... (hopefully) you make a plan to have a child, (hopefully) wait 9 months for the child to arrive, then just 3 months later you wonder why things aren't working out like you planned

case structure selectors are case sensitive by default (you can turn that off with a right click selection)

OK. This was posted on the 12th, then Darren says he was speaking with someone last week and learned this little nugget...

Yes, MythTv...that's what I meant.. Thanks Tom.

However, I don't think that it does what I want to do.

I'd like to either select programming from a local jukebox, or from Internet TV (streaming video).

Having similar features to MythTv would be a longer term hobby project.

JLV

Is he finally gone from Canada..

Did the secret police pick him up??

I'll have to call my Jewish friends and send them after him

Shame.... My Romanian friends say they don't want him to return to Romania.. I guess Belgium should be fine.

Man... When I read his posts, it's like being on a bad drug trip...l. Woow... this dude must have tojken a lot of dope as a baby..

Chill dude... chill... 97% OF THE poPyulLation is NOtw a sEcrET POLliCE,... wOOOWWW.. My eyes... I see tripple, now!!!

Nah, on the NI Forum you need to post twice that many. :laugh:

Congratulations Mike!

Ben

LOL!!

Congrats Mike.

I need to visit this place more often. Especially with all those Imaging experts!

Ray

Taking that route, why not make it simpler- find a wavelength that is not visible but eye safe, IR as a possibility. The chosen wavelength would need to also reflect nicely off/within the eye. This should improve your signal/noise ratio. Then it is basically down to finding the two bright reflecting areas and testing if they disappear (eyes closed). Don't even need a camera for that, photodiodes would suffice.

Too bad our eyes don't reflect as well as animals, ever shine a flashlight into a cat or dog or horses eyes at night? You can see them from many 100's of feet away. :thumbup:

The only problem is how to deal with the driver glancing from side to side or any direction away from the detector... You'd get a lot of false alarms. The other problem is blinking. You'd have to sample long enough to avoid those..

JLV

Hopefully this is the right category for this question..

Has anyone used LV for receiving streaming video?

The video stream is typically .wmv or .asf.

I was thinking of using the IMAQ toolset to develop a webtv receiver which would have PVR functionality.

PVR = Personal Video Recorder

I think there was a project done in Linux that provided a means to distribute audio / video over a local network and create a "video jukebox" of some sort.

JLV

Good question dsaunders. I'd like to add if there are good LV libraries for license management, software keys, etc available out there... ?

You don't need a CD. The application builder is already installed. The only thing you have to do is to write in the license number for the bulder in the license manager - and - voila

Yeah, with LV 8 you just have to activate all your products, everything installs by default (except add-ons). I had a similar problem. LV Academic package Fall 2005 included a CD for LV 7.1 Pro but it wasn't Pro but LV 7.1 Base instead. The CD clearly says Pro... I wonder how many of these wrong CDs they shipped. At least two for me...

this would be better handled in OO...

That's why I keep saying I'm gonna have to learn OO someday. My wife wants more kids, and I don't know how to scale our current implementation! :laugh: Now I understand the term "family planning" better....

All I know is:

Copy, paste, resize...

Copy, paste, resize...

Copy, paste, resize...

After almost 9 Month of planning and a painful installation, the child process 2 began to work at 21:13 on my main Family system :laugh: .

Congratulations!

This new process may cause your utilization to increase exponentially (it did for me!)

I'm working on a LabVIEW library of SubVIs. I'd like to provide it free of charge for non-commercial use and with some fee to commercial use to cover the expenses. I would like to protect the library against misuse of the non-commercial version somehow. If it was an application, I could display in the beginning that this application is only for non-commercial use. However, it's not an application, but a library of SubVIs. Does anybody have any good ideas how to protect SubVI library against non-commercial license misuse.

I suspect that no one on LAVA can/will answer such a question. Most members are professionals that would only cause them self harm by answering. Software available via P2P is often mislabeled, hacked, or functionally limited. I would suggest that you download legal demo versions if you have interest in upgrading. There are also educational versions available at a discount. LAVA moderators will delete the posts and accounts of anyone requesting serial numbers or codes.

I'm not a beta program member, or privy to any inside info, but in an attempt to your question; there is one post here on LAVA that hints at 8.1 / 8.2. Based on this, maybe information will be available after the first week in August?