LAVA 1.0 Content

What would be the most simple: Open up all the VIs you are ever interested in and do a 'Save machine' on the offending VIs. That should do. Or open up all VIs, do a find (ctrl-f) and do a replace (new feature in LabVIEW 8.5/8.6) What you could do is place the 'new name' inside the VI with the 'old name', and let the 'old name' VI write to a log-file if it is called. After some time you know exactly which VIs are calling the 'old name'. Keeping this routine in place can be very usefull. Ton

QUOTE (Karl Rony @ Dec 17 2008, 04:18 PM) QUOTE (Aristos Queue @ Dec 19 2008, 02:23 AM) I agree. The XControls are useful only for UI heavy projects. And LVOOP only for heavy data projects. :headbang: What XControls need is their own Stephen Mercer, AristosQ. Someone that is very proud and convinced of their possibilities, keeps discussions on a high level, write several XControl Frameworks with thoughts when to do what. QUOTE (neB @ Dec 22 2008, 05:33 PM) Could we add "active Objects" to LVOOP? This would require creating instanciating the object and creating the by reference method infatructure (most of what I described above). I think one of the OpenG infrastructure have this. QUOTE Re: The XControl-LVOOP combo .... The only short-coming I see in the XControl is you have to go through gyrations to get them to "tickle" themsleves. Ben, What is it that you exactly mean by 'tickling'? An option would be user event from the owning application that runs in a timed loop and is triggered every run. One question about your application, what was the FP element that represented the dynamic object? Ton

QUOTE (crelf @ Dec 22 2008, 09:34 AM) It looks like he's not the only one. I'll have to have a talk with the guys upstairs.

QUOTE (Aristos Queue @ Dec 19 2008, 06:37 PM) Here are just some thoughts. I'll let others judge their validity. I have only delivered one LVOOP app to date and I had to teach myself enough OOP to implement same. Since I only have one to base my opinion on I will share what I had to do since I did not know how to do it the right way or the the tools where lacking. App Descrition: "Create Controls on the Fly" application deployable to any Winodws machine that allows for additional "screen object" deployment without modifying the application. I choose to develop it using LVOOP since it allowed dynamic dispatching in a built app. The "additional screen object" (Things like buttons meters... we called them "plug-ins") could be loaded dynamically. When I had new object ready for deployment I just added folders and classes as required. This was GREAT! It was probably the biggest feature that finally allowed me to get a buy-off from management to use LVOOP. But I am digressing... So my applicaiton consisted of a set of "Core" classes that provided a vinella flavored interface to the Plug-ins that let them recieve/send updates from/to whatever while also allowing user interaction. Most of the work I put into developing the "Core" focused on keeping all f the "plugins" running independently while also being efficient. To maintan independence between all of the plug-ins I choose to create sepearte background processes for each Plug-in. This allowed me have a while loop a the heart of every Plug-in. The while loop gave me two things. 1) It gave me shift-registera so that I could control my memory usage to my hearts content. The SR stored the class state data for that instance of the class "Plug-in" 2) It allowed me to create chlildren of the Class "Plug-in" that where capable of "tickling" themselves. In my cases a scrolling marquee of class Plug-in >>> Text >>> Indicator >>> Scrolling that would update its image regularly. Each instance of the class Plug-in was insatciated by the Core by creating command, responce and update queues and then "instanciate" the object by loading a template of the selected class. The queues allowed other parts of the appliaiton to invoke methods for any of the Plugins instaces. So this represents my adhoc by reference architecture. There is alot more built into the core but is enough detail to touch on what seemed missing cumbersome etc. Could we add "active Objects" to LVOOP? This would require creating instanciating the object and creating the by reference method infatructure (most of what I described above). Re: The XControl-LVOOP combo Not yet but someday. The only short-coming I see in the XControl is you have to go through gyrations to get them to "tickle" themsleves. BTW: if any of you would like to tell me why my above described approach is wrong PLEASE straghten me out. Just my 2 cents, Ben

Have you ever looked at the LabVIEW online help (or webbased). It contains a list of all VIs, properties, methods and events. Ton

The Top Left Visible Cell property is your friend. Ton

Hello there, Is there a way to programatically control the scrolling of a tree control. Basically i am having a tree control and a list box with some pretty good amount of data. I would like to scroll the list box which in turn also should scroll the Tree control. Has any one done it before? QUOTE (guruthilak@yahoo.com @ Dec 22 2008, 08:00 AM) ok i could not find a solution for this. instead i used a combination of "Scroll bar" control a "list box" and a "tree control" and used the property "top row" and "top left" to accomplish the same...

QUOTE (Minh Pham @ Dec 21 2008, 11:39 PM) LAVA CR to the Rescue. Have a look at the Array Point to RowCol submission. Ton

Easydaq has an USB-powered 240V relay card. Ton

QUOTE (Minh Pham @ Dec 20 2008, 12:51 AM) According to the specs of this module it would be able to handle up to 60W, but not a 100W light bulb.

QUOTE (Minh Pham @ Dec 19 2008, 11:54 PM) You would need to use the 5V output to control an external relay which switches on and off the 240V for the light. You can not simply pass the 5V through a transformer. You could use he NI ER8/16 or a SSR digital module for the external relay.

I posted today a question on Stackoverflow and wow, within a few hours some good and thoughtful answers. To promote LabVIEW I suggest all RSS readers to subscribe to the LabVIEW tag RSS-feed. Ton

Re: Graph/chart similar to XControls QUOTE (Aristos Queue @ Dec 18 2008, 08:23 PM) Finally admitted in public! I was convinced when I saw some of the bugs in the new version of the LV objects that came with LV 8+ that those would be bugs I would have wriiten if trying to implement graphs/charts/tables myself. I have experience with XControls and LVOOP but not what I was concider a lot. They have both served well but I have never managed to combine the two in a single app. I found working with both a good mental exercise. XControls require I think about how to do things "on a shoe string" (refs and terminals only) but still maintian good performance. LVOOP forced me to change my model for thinking about my functions (where is the data?) but once it started to click, I found myself delivering 2.5 as many classes as the customer originally required*. Re: "all this talk of OOP..." I have sensed the same vibes. It feels a little like being a hockey player in a meeting for a figure skating team. "What is with all this talk of perfect figure eights? Just bash the competition into the boards and skate right pass them!" I listen in on the OOP discussions since they "help me expand my repertoire" (maybe I can do a figure eight to get around that defense man). American Football Story Back when the Steelers wone their first 4 Superbowls, Lynn Swann was blowing away people with his arobatic catches. It ws common knowledge here in the 'burgh that he had studied ballet as a youth. And if the OOPish talk just becomes too much, switch over to the Dark-Side for a while. They hardly know how to spell LVOOP over there. Ben

Yes, there is. A summary and guideline is given in LabVIEW Bug Reporting on the LabVIEW wiki. Ton

QUOTE (Val Brown @ Dec 18 2008, 09:25 PM) Here, here! Ton (now about the rest of the post )

Dear friends: Do you know how to find out database quickly without entering so many university libraries and search the web again and again? Do you know what databases does a library have? You will recommend google search engine, but does it provide you enough and prcise information? No!So we made up this handbook for you guys as an index of library resource menu, for you to get to any database or journal without entering lots of university librares. here is the handbook! You can download the hand book here or link: you can go to

Could you add a piece of code? If you want to add a screen shot I recommend the Code Capture Tool. Ton PS Welcome

I only dipped my toe into the pre-LVOOP versions of OOP for LV. I avoided the previous versions since "I could not attack the core" meaning I had to leave the core the way it was and therefore had to copy the data out manipulate it and then put it back. Most of my apps require high performance and I cringed at the idea of not being able to "work in-place". I have become rather fond of LVOOP since it lets me "work in-place" and the "by-reference issue" (not built-in) is a non-issue for me since I just implemented my own version in LVOOP. Ben

QUOTE (Val Brown @ Dec 18 2008, 01:22 AM) If you use Endevo's toolkit with a by-ref class, you will be able to run these code without having Endevo GOOP installed (just like using an event structure in LabVIEW base), but you won't be able to adjust the Class behaviour. This goes for most of the GOOP's implementations, using the implementation is OK, editing class behaviour might be restricted. Ton

Have you looked at the Skype4COM documentation? https://developer.skype.com/Docs/Skype4COMLib It has a complete list of the classes and methods/interfaces.

QUOTE (jdunham @ Dec 17 2008, 07:22 PM) I have written an XControl for a colleague of mine in rather short time, which we later promoted to be part of our standard library, the most flattering thing he said was 'I didn't even want to look inside the XControl, it just worked'. And there is the catch-line, with XControls you are reducing a lot of code into one control with properties and method. If you think about the graph and chart as they are currently available, think how they would be in native LabVIEW code... If you would have to do the housekeeping of data, properties, alignments, visibility of items. All these things can embraced by XControls. So my answer would be 'XControls are in', way in. If I look at the different XControl applications to the http://forums.lavag.org/downloads.html' target="_blank">LAVA CR the diversity of coding styles inside those are good learning points, you see a lot of different styles. Ton

My thoughts on auto-populating folders: I agree with the original LVProject developers to not use auto-populating folders (the feature was added after begging from the users), creation of VIs should be done with the project in mind, currently I dump all VIs in a VI folder on disk and structure them in the project. Using auto-populating folders together with libraries (XControls/classes/lvlibs) can (and will be) very confusing. (my :2cents: ) I never had a need for auto-populating folders However I think LabVIEW ignores hidden files/folders. Ton

We have build XControls on top of LVClasses, where the data was sent in other VIs and representent in the XControl. Ton

Or you could build your own, the image data returned from a read png file contains the alpha blending info, if you really want to you could write your own alpha-blending routine. You would need to get the image behind the picture control and do your calculation but that should be doable. Ton

QUOTE (jeffwass @ Mar 2 2005, 02:10 PM) A sub-panel can be used to make a tab page adapt to chaning req's. Just load the req'd FP into the sub-panel. No scripting required. Ben