LAVA 1.0 Content

QUOTE(LV Punk @ Dec 19 2007, 06:40 AM)

I was thinking the same thing when I noticed some of my NI forum posts has some tags applied. I commend the people who are trying to add the tags, but I don't see how tagging a post about using SLIP and PPP with the tags SLIP and PPP is going to improve the experience. If tags are to be used, it should be to tag a question asked from a non-LabVIEW perspective with LabVIEW vernacular or with words that can lead a reader to a solution to their problem. The keywords SLIP PPP are already there...

...

I'll confess to that tag.

I have never used tags so I don't understand the rules. Lacking rules, I just made up my own. It is not the individual tag words themselves that are important but rather the tags that are used together for the same post. In the case of "SLIP" that tag will also show you the related tags, in this case "Bluetooth", "IP_Over_Serial", "PPP", and "VI_Server".

My hope is to build a web of realted terms such that novices can chase down related terms that do not show up in a normal serach.

And for my part, I use these backwards when I can't remeber "SLIP" but I can remember IP_Over_Serial.

And because the tags are all public, I can use the realationships defined by others.

As to tagging on LAVA;

The earlier we start it, the better LAVA will be in the long run.

Ben

PS:I will re-post some of this to the afore cited NI thread to try and get more feedback.

QUOTE(rolfk @ Dec 19 2007, 12:18 PM)

Windows API: Get/SetTimeZoneInformation http://msdn2.microsoft.com/en-us/library/ms724944%28VS.85%29.aspx' target="_blank">(link)

But it's not a trivial API and you have to do potentially some extra stuff such as getting a system Time structure correctly filled, etc. The one thing you can't avoid is that you need to adjust the application privilege before you can change the system time information. Because of that it would be best to write an external code DLL that does this all in a neat and proper way and import this as a single function into LabVIEW.

In the discription to the TIME_ZONE_INFORMATION structure it states that to disable daylight saving time you need to set the month value in both date structures to 0, among a few other conditions.

Rolf Kalbermatter

Thanks for this Rolf,

I was hopping it would be easier than this...

QUOTE(Justin Goeres @ Dec 18 2007, 10:06 PM)

They seem great for associating searchable criteria with things that don't intrinsically include searchable data (for instance, it's hard to search for "pictures of horses" or "Ukrainian Gypsy Punk Music"). But LAVA posts strike me as being eminently searchable by virtue of the fact that they're text. :2cents:

I was thinking the same thing when I noticed some of my NI forum posts has some tags applied. I commend the people who are trying to add the tags, but I don't see how tagging a post about using SLIP and PPP with the tags SLIP and PPP is going to improve the experience. If tags are to be used, it should be to tag a question asked from a non-LabVIEW perspective with LabVIEW vernacular or with words that can lead a reader to a solution to their problem. The keywords SLIP PPP are already there...

Some time ago there was some feature on the LAVA forums that would auto-rewrite things like LV as LabVIEW or NI as National Instruments. Maybe something could be done with the Wiki tagging to automagically add links to the Wiki subject for "http://wiki.lavag.org/functional' global variable" title='LabVIEW Wiki article on functional global variable' alt='Wiki article on functional global variable' style="border-bottom: 1px dotted #3366BB; color: #3366BB; cursor:pointer; text-decoration:none;" class="wiki">functional global variable" (added in this case using Insert Special Item) by simply mentioning it in a post; or maybe a button at the top of the editor window to "create links for recognized Wiki terms" if automagically is too intrusive to the members.

(After posting, I see that "L_V" is still rewritten as LabVIEW )

Hello,

In order to get the correct local time with a timestamp in countries that have a summer time and a winter time (daylight saving stuff) the property has to be disabled in windows.

So my question is, how to programmatically enable/disable this windows option ?

Thanks in advance

Hy all,

I have got a verry big programm running on an LabVIEW RT System (8.2.1).

The programm involves motion control, analog/digital I/O, CAN bus...

I made some minor changes (change the datatype of shared (local) variables) and a little extension of the programm.

When I run the programm from my host computer - everything works perfetct.

When I Build and distribute the application I dont'd get errors.

When I then restart the RT- system, the application doesn't start!!!

With the RT-System Manager I can see, that there is my application - but the execution state is bad and not running top level.

When I distribute the old application, everything works fine.

Has anyone an Idea?

hi

tanks for reply

i want to inactive 'use defult if unwired' and it gives the prevues amount..

beacuese i want to use that and i donot want change that

tanks

best regard :thumbup:

hi

i have problem with case structure .

i have case structure with 2 case (true,false),false is defult ,when case is true i generate code.but i must to use unwire defult ,in this time my code chenge .i use this code for shift register that use in the future i cannot get true code :headbang:

best regard :worship:

QUOTE(jlokanis @ Dec 17 2007, 06:17 PM)

It was not memory fragmentation afterall but rather a resource leak cause by this little bugger:

http://lavag.org/old_files/monthly_12_2007/post-2411-1197933305.jpg' target="_blank">

KeKeKe - Pwned by LV!

QUOTE(Yen @ Nov 8 2007, 07:06 PM)

I didn't see any great positive reaction or helpful suggestions, and I've been quite busy, so I put it aside for a while.

I still use this all the time and it's great, but as I said, it has some issues.

The single biggest issue is managing the names and aliases and it has several sub-issues:

• Getting the item names in versions below 8. At the moment I can think of four options:
  Build them manually (not really an option).
  Hack the mnu files. I gave it a quick look and it doesn't look easy for primitives.
  Do the palettes in 8.x and find a way to change whatever needs changing.
  See if the palette API can handle mnu files from 7.x.
  
• How to generate unique and consistent IDs for functions?
  If the IDs are not unique, some of the functions will be in the list, but selecting them will drop the other function.
  We could generate a unique list for each computer, but then the lists will not be exportable between computers, unless we come up with a way of preparing them for export. That might actually be the most practical idea.
  
• One option I thought about was using namespaced strings instead of I32, but I'm not sure how that will affect performance and it's still not guranteed to be unique and consistent.
  
• How to manage function names which change between versions. I don't have an example off hand, but I have seen NI VIs and primitives which had their name changed. This will only need to be changed in one place (where the ID is), but the key would be identifying it. Maybe scan the entire previous list when upgrading and display all entries which don't match?
  
• And speaking of the previous version list, I still haven't thought about a useful structure for managing different versions and toolkits. We will probably need a hierarchy of separate files and folders.
  
• I haven't thought about a useful UI for managing the aliases (adding, changing, deleting).
  

Hi Yen,

I will install your tool and test it "roar", I mean without looking into the code, it probably the most appropriate way to give a feedback on "does it help ?"

I'll let you know in this thread after christmas.

Thanks for sharing this tool.

Alfa,

After splitting half a bottle of Jim Beam with my buddy last night ( post CLA exam ) I paraphrased you by saying

"A dream is a solution to the qunatum-mechanical equation of our brian."

He stoped and ask me to repeat it, and after he declared

"That's it! That's exactly right."

Ben

I try it on two other computers:

1st with LV8.2.1 : the vi work fine

2nd with LV 8.2 : The vi does'nt work fine

Ouf, I don't need to add the key MakeTheProgrammerCrazy=False

Somebody with LV8.2 can confirm that is related to LV8.2?

Thanks to all, I will upgrade!

QUOTE(crelf @ Dec 14 2007, 02:43 PM)

It must be MakeInRangeCoerceWork=FALSE

Was there a bug in the N terminal with constant folding?

TO many bugs, so few brain cells....

Ben

QUOTE(gleichman @ Dec 14 2007, 01:33 PM)

You're VI worked for me (WinXP, LV8.2.1). What results were you expecting?

uhm... This is what I get for the first run:

And this is what I get for the second run:

I use WinXP and LV8.2

Can it be a LabVIEW setting?

I use the In Range and Coerce Function to coerce the N terminal of a for loop but the output is never coerced.

Also if the N terminal is in the range for the In Range and Coerce Function, the In range output need two run to turn on.

Anybody can explain this strange behavior? :headbang:

See the attached code.

tank u

QUOTE(RovingCalypso @ Dec 14 2007, 03:28 AM)

Can anybody please convert the following matlab code to labview? It will be a big help.

I think you'll need to separate the UI functions from the calculations before you can implement this in LabVIEW. MathScript can be used to perform some of the calculations, but the I/O functions like "input" "polar" "text" etc... are not really applicable.

The functions used are basic enough that you shouldn't need to use a MathScript node at all. Break the Matlab script into logical parts. such as "get number of poles", "create a 50 element array of angle,length pairs", "for each element in the array, calculate angle,length using a constant value, a 'cos' function and the 'number of poles'", "plot data".

Don't try to update a polar chart graph on the fly in LabVIEW.Think this way, "Gather inputs", "Calculate points" and finally "Present output". The updating of the polar plot during the calculations was probably done in the Matlab script because it's convenient. It can be done in LabVIEW but will complicate your code.

If you're not familiar Matlab OR LabVIEW, I suspect this is going to take you a long time...

QUOTE(jlokanis @ Dec 13 2007, 06:24 PM)

I am launching 100s of these VIs from several instances of a reentrant VI every minute in my system and want to avoid anything that might make a bottle neck.

launching 100s every minute from several instances of a reentrant vi ?

Care to describe your system a bit more?

thank u for your advise .

i can work with the simple tools in labview but i can understand how to use , property node , active x , local variable

tank u for your attention .

Hi Everybody

your forum is too majestic.and i see that for the first time .i am sorry if i cannot speak English well .

I am Beginer In LabView . I want to know that I can use variable like Other language (for Example in the delphi i define variable like this : var x:integer;)

beacuse i want use some value in case loop (case 0) that excecute in other case (case 1) and in dont like to use for loop .

if your answer is yes please explain that .

please guidance me for application of labview .i indeed thanksful :worship:

best regard

The reference time for LabVIEW is 12:00 a.m., Friday, January 1, 1904, Universal Time. So you have 1462 day offset.

For excel you have the correct reference time but don't forget that it's not in UTC format.

Eric

QUOTE(jlokanis @ Dec 12 2007, 06:43 PM)

So, why for option2 since it seems much more complex? Well, the idea was the Ctrl Val.Set method modifies FP terminals so it should/might/does cause a thread swap to the UI thread, something that is not good when speed is concerned.

I just used 'option 1' on a side project and it works well (just last week!). The only comment/question I have is why you would be concerned about the thread swap? This hit occurs only when you start the dynamic VI. If you're randomly starting large numbers of instances based on UI events AND these instances are CPU intensive or time critical, then you might risk delays or data acq loss.

I start the instances with one subvi (see picture). I also included two queue references; one for commands to and one for responses from the dynamic vi. I've used the Command ref, but haven't used the response queue (yet ).

Overall, I like this idea and will probably use it more :thumbup:

QUOTE(Yuri33 @ Dec 13 2007, 01:45 AM)

Option 3) Would a functional global work? Even though you dynamically spawn a VI, I believe any embedded functional global should still contain whatever you wrote to it in the calling program.

I guess the reason why the dynamic VI is set to re-entrant is because it's going to be used at different places with different sets of data.

So using a functionnal global would require great care and might cause race conditions, no ?

I am always a bit scared of setting my VIs to re-entrant, the first reason is that I'm not self-confident enough in my own skills and the second is that I never really needed them. And third, now there are different type of re-entrant VIs and I didn't really understand the differences

"We are limited not by the vast domain of the possible, but by the space inside us"

QUOTE(Graeme @ Dec 12 2007, 03:38 PM)

Hi all,

I have a complex (by my standards, ~ 100 VIs) top level VI. At its most basic level it contains two tab controls, each with multiple pages. It's essentially my effort at a test executive (didn't fancy learning, or paying for, TestStand). When the test sequence is complete, I write to one tab control's tab captions some (irrelevant here) default values.

Problem is, instead of those values appearing simultaneously and instantly, they appear at about .5s intervals, i.e. I can watch my tab control's tab captions being updated one by one, half a second apart. The functionality of the top level VI, of course isn't affected, but it's very irritating. It's difficult to post the whole code because of its size, especially as it's such a trivial matter. Earlier in my code, I can update the tab control's captions instantaneously, as you would expect.

To, summarise, has anyone seen a slow update of tab captions, and if they did, did they ever find out why? I'm chopping my code down bit by bit to see what might be causing it. Thanks.

Regards, Graeme.

I can't say I've seen that issue but I have seen tab update issues.

In most cases they update faster if you

1) Defer Front panel Updates

2) Hide the tab control (set visable false)

3) Do your update

4) Show the tab control

5) Undefer FP updates

Like I said, I don't know if that will help!

Off-the-wall question

is the update fast when the tabs are "empty" and slow down when tables graphs etc are filled in?

Ben

I know some of you will want to kill me for keeping this thread going but....

1) Wasn't the transistor just an experiment to prove that quantum mech effects can be measured at a macroscopic level?

Don't know about dreams but...

2) Couldn't a "simple" memory be viewed as "memory quantum"?

For the memory quantum, I am thinking about those things you manage to pull out your "arse" and you actually suprise yourself? The smell that brings back memories of Grama's house, The question from your better-half "Do you know where I left my glasses?" etc. It "seems" that the whole brain is is hit with a "query field" and if the memory is present, the system colapses into the "recall function".

Although I can not propose methods to measure this "system", I also fel we will never figure out how to measure something that we refuse to test.

AE had to cast aside the absolute nature of simultanaity (sp?) before his thought experiments could move forward.

Sorry about dragging it out.

Ben

PS: My terminology could stand some improvement. Please try to read what I meant and not what I said.

I was reading this article this morning, and decided to check out the products mentioned. The two companies sell static source code analysis tools to detect race conditions. They are in the same business, have practically identical home pages, and even the customers shown in the 'crawls' are basically the same.

National Instruments is shown in both lists .