Visual C++ VS Labview?

Hellow,any one know are there any advantage to use VC++ to do the measurment compare with using Labview?
which one is better? thanks!

Hello Happybird,
If you have no experience in programming language C++ or no fundamtenal knowlegde in object programming language you should use LabView.
LabView is a graphical progamming language. If you are an electronic it is like drawing a schematic. It is very easy to learn. In a few minutes you a have a really nice application with sliders, buttons, knobs and connection to a measuerment device.
If you like to do this with vc++ without Ni Measurement Studio --> forget it!!
If you have some expericence and Measurement Studio on your machine --> maybe in one Day!
Well I am using VC++
In my opinion the one of biggest advantage for using VC++ is there is no need for the Labview Runtime-engine on your machine(An applikation never runs only on the develop
ment machine).
The biggest advantage for using vc++(with Ni Meas.Studio) is that you can use several Forums:
MSDN, NI, Codeproject, Codeguru and so on.
I think this very important because you can save in most cases a lot of time by sharing code.
Greetings Juergen

Similar Messages

DateAdd(interval,number,date) Visual Basic to LabVIEW Time Stamp add 18 months

Hi all,
I need to match Visual Basic Cmd = DateAdd("m", 18, Date()) which adds 18 months to today's date. When I use LabVIEW Time Stamp VI's at first I tried adding 1.5 years in seconds. but this did not match the VB generated method? What method do I use in LV to obtain the VB DateAdd("m", 18, Date())
Example 'Add one month to January 31, 2000
document.write(DateAdd("m",1,"31-Jan-00"))
Output:
2/29/2000

Well this is how you do it. However, it doesn't seem to work with the month. There was a thread about this problem not too long ago. If you overflow the month in the date/time rec cluster (so it is greater than 12), date/time to seconds returns 0. Every other element works fine. You can add 1000 to the day and it will figure it out just fine. When this bug is fixed, this will work. Also, it might only be a bug in recent versions. I'm on 8.5 and it doesn't work right.
I realize this isn't a great answer to your question, but as far as I know, this is the easiest way to do what you want and have LabVIEW handle all the work.
Message Edited by Marc A on 10-03-2007 03:56 PM
Attachments:
Example_BD.png ‏2 KB

Visual Glitch in Labview 8.2 for OS X

Hello,
I recently got LabVIEW 8.2 for Mac OS X and I'm having some problems with visual glitches in block diagrams. When I scroll the window, everything looks ok until I mouse over something (a wire or a function). If I mouse over a function for example, a second image will appear where the function originally was before I scrolled the window. If a structure is highlighted, the corners and centers of each side will turn white where the resize squares would be.
Minimizing the window or dragging something else over the window does not fix the problem. Closing the block diagram and reopening it or scrolling it completely off the screen then back on does fix it, however unless I switch to the front diagram and back the glitches simply happen again. I attached a screenshot of the problem, let me know if anything else would be helpful.
I'm running OS X 10.4.10 and have an ATI Radeon 9600 with a 20 inch cinema display.
Thanks,
Mike
Attachments:
LabVIEWGlitch.jpg ‏179 KB

I contacted support about this problem and they were able to reproduce the problem. Since I didn't find anything about this problem when I searched the forums, hopefully if anyone else runs into this they can find this thread.
The things I do to get around it are:
1. Don't scroll with the mouse wheel. Use the scroll bars on the sides instead.
2. If you do scroll with the wheel, switch to the front panel and back before you mouse over anything.
3. If the screen gets messed up, closing the block diagram and using ctrl-e to immediately open it again is probably the best way to fix it.

ActiveMovie Control,Translating ActiveX calls from Visual Basic into Labview

Hello,
I want to use DirectX to display a movie. In the attached file is a Visual Basic example
which I tried to translate into Labview.
To play the movie IMediaControl from ActiveMovie control type library Version 1.0 C:\WINDOWS\system32\Quartz.dll) is used.
To display the current Position I tried to wire the IMediaPostion. But I have no idea how to implement this in the Block Diagram.
After opening it the following message is shown.
Error 3005 occurred at Automation Open: Object specified is not creatable in Play Movie Current Possition.vi
Attachments:
Play_Movie_Current_Possition.vi ‏48 KB

Hello Joe,
the Windows Media Player has a lot of overhead. I also found it difficult to deal with the different Versions.
I want to display data in a graph and show the connected video frame in a separate window.
I used the QuartzTypeLib because it is on every Windows Computer and is easy to code in VB.
With one call I can start the video in Labview., but I find no way to wire the current position. I do not really understand how ActiveX is implemented in Labview. I attached a LV 7.0 vi. I hope you can open it.
Tiemo
Attachments:
Play_Movie_Current_Position.vi ‏63 KB

Visual source Safeを使ったLabviewでのソース管理

現在，Visual　Source Safe 2005を導入してLabView2009のソース管理をしようとしています。
どうもLabViewプロジェクトからチェックインチェックアウト等ができるようなのですが，ソース管理に追加を行う段階で
マップできませんというエラーで行き詰ってしまいます。どなたかやり方をご存知の方がいらしたら教えてください。
手順書があるといいんですが…探したけど見つかりませんでした
解決済！
解決策の投稿を見る。

平素より弊社の製品をご利用頂きまして誠にありがとうございます。
日本ナショナルインスツルメンツ技術部の巳波と申します。
>ソース管理に追加を行う段階でマップできませんというエラー
というのは「ファイル c:\○○○(VI名).vi は SourceSafe プロジェクト $/ にマップできません。」
というエラーでしょうか？
このエラーメッセージが出る際の対処方法であれば
こちらのリンクに書かれております。
http://digital.ni.com/public.nsf/allkb/4EF19D60E9C69EF6862571E7004832F7?OpenDocument
スクリーンショットも貼っておきます。
こちらに書かれている方法は
1. LabVIEW を開く
2. 「ツール」をクリック » 「ソース管理」 » 「ソース管理を構成..」
3. 「ソース管理プロジェクト」欄の隣の「変更」をクリック
4. 「フォルダに新規プロジェクトを作成」欄に場所を入力する、
或いは「ブラウズ」をクリックして場所を選択。
5. 「OK」をクリック
6. 「OK」をクリック
7. 今後ソース管理プロバイダよりチェックアウトされたファイルはこの新しい場所に保存されます。
という方法です。
もしエラーメッセージが異なるようでしたら
何というエラーメッセージが出ますでしょうか？
宜しくお願い致します。
日本ナショナルインスツルメンツ株式会社　技術部　巳波裕介
Yusuke Minami, Applications Engineering, National Instruments Japan
技術サポートウェブページ:　http://www.ni.com/support/ja
お問い合わせフリーダイヤル:　0120-527196

How to make a link between Visual C++ and LabView?

I want to use my labview program to read the data generated by visual C++ program to perform some control to digitial oscilloscope. I have read your homepage. I know it is using ActiveX to get everything done. However, I dont know where to get started!The data is just a simple number, 1 to 8. So what should I do right now? Where Should I start?
thanks for helping me.

Possible alternatives to ActiveX calls:
If you program can save the data to a file, then you could read the file from LabVIEW and act accordingly.
If the data is generated by a function that is in a .dll, you can make a call to the function from LabVIEW using the "Call Library Function".
If you have the code of your C++ program, maybe you can work a CIN that will work directly from LabVIEW.
There can be other alternatives.
Regards;
Enrique
www.vartortech.com

Passing Array of Srings between Visual Basic and Labview dll

I have searched and searched for the correct way to pass an array of
strings between Visual Basic 6.0 and a Labview 7 dll. So far, I still
do not know how to pass the array. When I create the dll in LV, the
array of strings is presented as a string, not an array. I am familiar
with passing arrays of type double, but I really need to know how to
pass an array of strings. Any and all help is appreciated.
Bob

Hey Bob,
From what I understand, that can get kind of messy. You have to allocate the memory in VB in the format that LabVIEW expects (see the externalcode.h file in National Instruments\LabVIEW 7.0\cintools for details). Then pass a pointer to that location to LabVIEW. There are a couple of related examples online. They don't necessarily show how to pass an array of strings to VB, but they should show how to pass a string and an array. I hope this helps.
Using Microsoft Visual Basic to Call LabVIEW DLLs That Pass String Data Types
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B123AE0CB9B0111EE034080020E74861&p_...
Using Microsoft Visual Basic to Call LabVIEW DLLs That Pass Array Data Pointers
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3D9E556A4E034080020E74861&p_...
Regards,
Chris J

Using a Visual Basic ActiveX DLL in LabVIEW

I' like to use some code written in Visual Basic into LabVIEW. I think the best way to do this is making a dll_activeX. I've seen an example on NI site: http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B123AE0CB992111EE034080020E74861&p_node=DZ52048&p_submitted=N&p_rank=&p_answer=&p_source=External.
When I use the dll present in the "zipped" file it works (I've registered the dll as described in the article).
If I compile in a DllActiveX the Visual Basic project (Visual Basic 6.0), present in the zipped file, and I try to use, after the unregistrtion of the old one and the registration of new one, it doesen't work.
I received the following error:
error 3005Occurred at automation open: Object specified is
not creatable in a ActiveX Dll with LabVIEW.vi
Some ideas?
Thank you.

Paolo,
I am not sure why you are getting the error. I downloaded the zip file re-built the dll and then registered it. I originally had LabVIEW open, so I closed and re-opened it so that it would see the new object. I then pointed the ActiveX refnum to the Project1 class. I still had a few broken wires so I hit ctrl-shift-Run Arrow to force a recompile.
After all that I ran the VI at it worked great. Once that was done I unregistered it and ran the VI. I got an error as expected. I then re-registered the dll and ran it again. No error.

Suggestions for writing application in Visual C++

I am in the process of converting an old DOS data acquisition program into Windows 2000/XP for ComputerBoards, Inc. data acquisition boards. I have written a VxD device driver so that the board will work in Win95/98. I have also written a Visual C++ interface that talks to the VxD. To get it to work with Win2000/XP, I know that I need to port the VxD to WDM (not too fun!).
Recently, my boss visited a lab which uses the NI-660x board. He wants me to try to use this board in my application instead of the Compuboard.
So, my question is this....what is the best/easiest solution? I want to reuse as much code as possible, so I don't want to trash my VC++ interface code. Also, I don't want to write a device dri
ver for the NI board. I looked on the NI web site, and it appears that there is a NI-DAQ software library that would allow me to control the NI board. I also saw on the web site that there is LabView, LabWindows, Measurement Studio, etc, etc. But, these seem to yield the most benefit when you are designing an interface. Another disadvantage is that they cost a lot of money, whereas it looks like NI-DAQ ships with the board. Therefore, it looks like NI-DAQ is the way to go???
Any suggestions (or horror stories about programming with the NI-DAQ library) would be welcomed.
Thanks,
Trina

NI-DAQ is the driver software and is free with the board. You DO NOT need to write your own device driver for the board. NI-DAQ provides a C-style API that you can use to program the board with from Visual C++.
Measurement Studio, CVI and LabVIEW are application development tools. They provide tools for analysis, user interface, networking, signal processing, etc. You don't need these tools to communicate with the board, all you need is NI-DAQ. You would want to consider buying Measurement Studio if you want to design a user interface for your program, want to do analysis (FFT, signal processing, mathematics), or need easy data publishing and network tools. LabVIEW and CVI are full development environments like Visual C++. LabVIEW is graphica
l programming and CVI is based on ANSI C. Measurement Studio includes tools that plug in to the VC++ and Visual Basic environments.
I'll let other users comment on the quality of our NI-DAQ driver software, but I think you will find that it is easy to use with many examples. If you have any questions about programming the 660x, just contact our support engineers via phone, e-mail, or this forum through http://www.ni.com/ask.
Best Regards,
Chris Matthews
National Instruments

Comment comparer deux builds LabVIEW générés à partir des même sources ?

Bonjour,
Dans le cadre de mon projet je souhaite m'assurer que LabVIEW génère deux executales identiques à partir des mêmes sources.
Or pour le moment j'obtiens bien deux executables de même taille, mais pas de même checksum.
Il est probable qu'une raison à cela est que le timestamp est présent dans le binaire généré.
Existe-t-il l'équivalent de dumpbin pour Visual C++ en Labview ? (cet utilitaire permet de s'affranchir de l'entête de l'executable avant de comparer deux executbales).
Sinon existe-t-il un autre moyen d'arriver à mes fins ? (option de génération de l'executable, utilitaire spécifique LabVIEW, etc...)
D'avance merci de l'attention que vous porterez à cette problématique,
Philippe

Bonjour Philippe2278,
Merci d'avoir posté sur le fourm National Instruments.
En effet, si vous lancez un File Compare (fc) entre deux exécutbale construit à l'aide du même code source et du même projet LabVIEW vous verrez des différences au niveau des deux binaires.
Malheureusement LabVIEW ne garantit pas un résultat déterministe pour la construction d'exécutable, DLL, distribution de code source. En effet, il peut y avoir des différences dans les horodateurs ou les différents choix faits pendant le processus. Le résultat final s'exécutera de manière identique et ne devrait pas affecter les résultats en terme de performence et de résultat.
Cependant il existe différents outils permettant de démontrer que votre code remplit bien tous les pré-requis de votre cahier des charges. Je vous invites a regarder tout ce qui concerne le Software Engineering in LabVIEW. Cette communauté traite du développement de large application en LabVIEW et aborde pas mal de point concernant la validation de code...
Benjamin R.
R&D Software Development Manager
http://www.fluigent.com/

Header files or Conversion of C into LabView

We are using NI DAQ board for a system. The code was written for an old board (AT-MIO-16DL-9, the new one is AT-MIO-16DE-10). Therefore the code needs to be modified slightly. Our code was written by someone 5 years ago. The code starts with header files:
extern "C" {
#include "C:\LW\INCLUDE\lwsystem.h"
#include "C:\LW\INCLUDE\utility.h"
#include "C:\LW\INCLUDE\gpib.h"
#include "C:\LW\INCLUDE\gpib4882.h"
#include "C:\LW\INCLUDE\formatio.h"
#include "C:\LW\INCLUDE\userint.h"
#include "C:\LW\INCLUDE\graphics.h"
#include "C:\LW\INCLUDE\analysis.h"
#include "C:\LW\INCLUDE\rs232.h"
#include "C:\LW\INCLUDE\ui_attr.h"
I was wondering where these header files are avaialbe, so I can re-compile the c
ode and use the system. We have MS Visual C++ and LabView. Are there any program which can convert a C program to LabView.

Hello Kelmer,
As mentioned in a previous post, those header files are for LabWindows/DOS. If you recently purchased LabWindows/CVI Full Development System you will have different header files. If you use a standard CVI function call in your program, the appropriate header files should be automatically loaded to your source file. All in all, you should not need lwsystem.h, even though you might need a comparable header file that is compatible with your newer version of CVI.
Thanks.
Wendy L
LabWindows/CVI Developer Newsletter - ni.com/cvinews

T440 or L440 for a student - not sure which to buy!

I'd like some opinions please...
I am a student in the UK looking to buy a laptop around late August/early September 2014. I will require the following from it:
Haswell i3 or i5
8GB RAM
1600x900 or 1920x1080 display
Windows 8.1 64-bit
Good build quality
Not too big or heavy, so a 14" display would probably be more ideal than a 15.6"
A touchscreen may be nice, but is not essential
I will be doing a lot of programming on it, so a good keyboard is a must, and I will be doing photo editing and web design on it too, so it needs to be powerful.
I would really like this laptop to last for a long time (and by that, I mean around 5-6 years) and to be well-built. I don't particularly have a budget, but the T440 specced out below comes to £835 and I'd say that is the very top of my budget.
I am keen on a ThinkPad (used to own an A31 and an R40) and looking specifically at the L and T series. I'd like to buy something new and with a Haswell processor.
I've specced out the following machines, do you think it would be worth paying the extra for the T440? Or would the L440 be perfectly adequate and last me as long as I'd like it to last?
L440 - £653
Intel Core i3-4000M Processor (3MB Cache, 2.40GHz)
Windows 8 64
Windows 8 64 MUI EMEA WE (EN FR GR IT NL)
14.0" HD+ (1600 x 900) LED Backlit Anti-Glare Display, Mobile Broadband Ready
Intel HD Graphics 4600
8 GB DDR3L - 1600MHz (2 DIMM)
Keyboard - UK English
Ultranav with Fingerprint Reader
720p HD Camera
500GB Hard Disk Drive, 7200rpm
DVD Recordable 8x Max Dual Layer
6 Cell Li-Ion Cylindrical Battery 56.16Wh
65W AC Adapter - UK
Intel Centrino Advanced-N 6235 BT Combo (2x2 AGN)
Integrated Mobile Broadband upgradable
Publication - WE (FR/GE/IT/DU/EN)
1 Year Depot or Carry-in
I could possibly buy a 256GB SSD for this to speed it up, or upgrade the i3 to an i5 4200M (but I think the only difference between the i3 4000M and the i5 4200M is the slightly higher stock speed on the i5 and the turbo boost?)
T440 - £835
4th Gen Intel Core i3-4010U Processor (3MB Cache, 1.70GHz)
Windows 8 64
W8 64 WE MUI
T440 14.1HD+ WWAN
Intel HD Graphics 4400 with docking connector
8GB PC3-12800 DDR3L SDRAM 1600MHz SODIMM
Keyboard - UK English
Fingerprint Reader
720p HD Camera
500GB Hard Disk Drive, 7200rpm
ThinkPad Battery 3 cell Li-Polymer (23.2Whr)
ThinkPad Battery 6 cell Li-Ion (47Whr) Cylindrical
Country Pack United Kingdom with Line cord & 45W AC adapter
ThinkPad Wireless 2 x 2 BGN with Bluetooth
Integrated Mobile Broadband upgradable
Publication - WE (FR/GE/IT/DU/EN)
3 Year On-site
I don't think I can spend more than this on a laptop.
My only worry is with buying the T440 is that it may draw attention and I may risk getting it stolen. I'll need to think about that.
Is there any massive reason to buy a T series over an L series?
I have looked that the L540 with a 1080p display, but I'd prefer to stick to the 14" laptops for portability's sake.
I am genuinely interested to see which you think would be better.
Thanks!

I recently acquired a T440s so I may be able to speak on some points, maybe not on others.
My specs:
i5 4200
4gb RAM upgraded to 8gb
Win7 64
256gb SSD
Integrated 4400 graphics
1600x900 HD+ screen
3 cell battery (plus internal 3 cell)
Other stuff..
I do not do anything worth mentioning with photo or video editing, but I do quite a bit of programming, typing, circuit simulation, etc...
The keyboard is very good. I have an R61 with what I always considered to be one of the best laptop keyboards I've used. This one is 99% that good. The trackpoint/trackpad combo works very well for precision visual programming like LabVIEW. The new trackpoint/trackpad setup is a point of contention among Thinkpad users, but I personally like it just fine. It is still WAY ahead of most cruddy touchpads out there no matter what you think of it.
Even though everyone raves about the new IPS 1080 screen on Thinkpads, the 1600x900 HD+ screen suited my needs fine, and I used to funds that would have been put towards the FHD screen to an external 23" IPS 1080 monitor. I will say, the 1600x900 TN screen really doesn't have the best color reproduction. I would not want it for photo editing. I would say either spring for the 1080IPS FHD display on the T440, get an external monitor, or both.
The i5-4200 with 4400 graphics has never left me wanting for more. It does all that I ask of it in simulations without any problems. The only CAD that I do is the occasional circuit board mockup so I can't speak to the effectiveness of the integrated graphics for your needs. I would look further into whether or not the integrated 4400 would be acceptable.
I am very glad i got the SSD. I picked up an external 500GB hard drive to handle backups and excess media. It's kind of a personal taste type thing. If you are OK with spending the extra money for less storage and a little pickup in speed then go for it. The fact that the SSD is not susceptible to damage from moving the computer around was important to me.
I find the computer extremely portable and light, though I am coming from a ~5.5lbs R61 that necessitated carrying around a 2lb power adapter due to nonexistent battery life. I get at least 5 hours out of the battery, usually more like 6 or 7 if I'm not doing simulations.
I don't know what it is like there, but I don't worry about theft in my college atmosphere. I guarantee if you put a Macbook next to a Thinkpad and walk away, the Macbook gets stolen. The Thinkpad is just an under the radar machine, and most students don't seem familiar with them. That said, my computer is never out of my eyesight. If you must leave it in a dorm room, get a good lock for it.
It's possible to save ~$40 and upgrade the RAM yourself. This procedure is not fun, but doable on the T440s. I have heard that the T440/T440P are easier to deal with.

Problem occured while creating a .dll file which has to be used in CIN

hi all,
i am a rookie in labview,iam getting an error while trying to build .dll file in vc++ 6.0 , i followed all the instructions available in labview "using External Code" manual,the error was as follows;
Compiling...
CINsample2.c
Linking...
Running LVSB Utility
The system cannot find the path specified.
Error executing c:\winnt\system32\cmd.exe.
sample1.dll - 1 error(s), 0 warning(s)
plz help.
santosh.
Regards,
santosh

Hi santosh,
It sounds to me that you are mistaking CINs (Code Interface Node) with
DLLs (Dynamic-Link Library). You mention that you want to create a DLL
in Microsoft Visual C++, but the errors you are getting are related to
CINs.
Don't worry! Here are my favorite links to getting started creating and using DLLs with Microsoft Visual C++ and LabVIEW:
How to Build a DLL with Visual C++
Creating and Calling LabVIEW DLLs with Various Data Types from Microsoft Visual C++
I hope that this helps you to get on the right path.
Have fun!
- Philip Courtois, Thinkbot Solutions

Modifying colors in images

I am trying to create a vi in Labview 7.1 that will upload an image from a jpeg file, modify the color and luminance of the image, and then output the image as a jpeg file. I am currently able to input and output the image to a file, but I am having difficulty modifying the colors of images. I read in a manual that the color control was a 32 bit array, but when I try to make my own array and wire it to the color control on the image block, it breaks the wire and won't let me make the condition. How do you design a proper array to set color and which array elements correspond to red, blue, green, hue, luminance, and saturation of the image? I am able to manually adjust the color and set my own color in rectangles, but I wanted to create an automated process with an array to automatically generate a range of colors.
The other problem I was having was getting the image to be displayed on the visual panel of Labview. I can import and export the jpeg file, but I cannot get it to be displayed on the grid. I would greatly appreciate any assistance and advice you have.
Thanks,
Daniel

If you are going to do some heavy image manipulation, you may wish to look into a LV toolkit called IMAQ, which allows you to go that way.
If not, you can start by using the standard picture VIs (Graphics & Sound palette), which I assume you already do to read and write the file.
LV treats a picture in one of three formats:
1. Picture - the blue wire. You will need to to use this for any manipulation using the picture VIs.
2. Pixmap. A 2D numeric array in which each cell holds the color value of the coresponding pixel.
3. Flattened pixmap. A cluster holding all the picture information in which the pixel data is stored as 1D array.
There are VIs for converting all these formats.
To replace colors you can simply use Replace Array Subset to replace specific cells either in the 1D or 2D array or use the Draw point VI. The main problem you will have is that you will need to calculate everything on your own. If you want to modify the entire image, you can go over the array in a loop and (for example) increase all values by 1000 and see what that does.
All of this can be found from reading the help files for the VIs (right click>>Help), which is what I suggest you do to learn more about this.
You can display an image simply by converting to the first format right clicking the VI output (picture) and selecting Create>>Indicator. because it's a picture format, a picture indicator will automatically be created.
It sound as if you don't have much experience in LV. Also, try searching this site and google for LabVIEW tutorials. Here and here are a couple you can start with. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide.
Try to take over the world!

Buffered Viewing of Waveform Charts?

We're acquiring very large data sets, using 'Cont Acq&Graph (buffered).vi' as sort of a template for the data acquisition.
The resulting files are much larger than physical RAM, but the researchers are only interested in small parts of the collected data: The researchers need to be able to go back over the data run, choose a few seconds here and there for permanent archiving, and then discard the rest of the data.
Because the size of the data run is larger than the physical RAM in the computer, the 'viewing and extracting' VI can read from file and display to screen [via a Waveform chart] only a few seconds of data at a time. Because hard drive access time is so much slower than RAM access time, I'd like to buffer this data view
[just a little to the left and a little to the right], so that if the researcher chooses to move a little bit back in time, or a little bit forward in time, the data will [probably] be cached in RAM and the VI won't have to make a relatively slow call to disk.
Of course, the art of buffering rapidly degenerates into a PhD level computer science mess [owing to not necessarily contiguous runs of not necessarily ordered data], and I really don't feel like writing a buffering algorithm from the ground up [especially not in a visual language like LabView].
I was hoping maybe the Waveform Chart might have some capability to perform [not necessarily contiguous and not necessarily ordered] buffering. Does anyone know if this is possible, or am I asking for too much?
Or should I just rely on the operating system [soft caching] and/or the disk controller/disk [hard caching] to perform my buffering [caching] for me?
Or do the standard LabView byte stream disk reading VIs perform thei
r own [not necessarily contiguous, not necessarily ordered] buffering?"

The waveform chart does keep a history of the data passed to it. You can set the buffer length at program time. When you read the data (the data desired + buffered regions) from disk you can polulate the history by writing to the history property node. You can then postion the data in the chart with a property node. Be sure to make the x scroll bar visible. (right click on the chart >> visible items >> x scroll bar). I attached a VI in LV 7 to demonstrate.
There is no telling if relying on the OS and hard disk controller will give you desired performance. I do not believe the byte stream functions in LabVIEW do any sort of buffering either.
You will have to experiment to see what works. If you as the user cannot tell between experiments then
chances are the implementation does not matter.
By the way, LabVIEW does not support abstract data structures because it does not expose pointer operations to the programmer.
Attachments:
Untitled.vi ‏24 KB

Visual C++ VS Labview?

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