LAVA 1.0 Content

QUOTE(balendran bala @ May 14 2007, 09:06 AM)

I need write Instrument driver for our Test Equipment product family consisting of multiple cards. If I write the driver in a usual NI conventional method, i.e. one driver for per card, then there will be lot of duplicate codes between them and pain to maintain. Base code is exactly identical among them (50 % code). So, need your expertise to identify the best approach to write the driver. Any help is appreciated.

Welcome to LAVA!

I've never written commercial grade drivers for card based (PCI/PXI/VME) hardware before, so I don't know if there are special cases for this. I can tell you what I've seen though...

Example: Fluke has a group of GPIB based instruments called multicalibrators. The NI driver for these instruments is a single driver download. The driver use a combination of the IDN query, VISA properties and an error handler to initialize the instrument and to check if a command is valid with that instrument. The driver sub-palletes are also broken down to allow selection of commands specific for the model. You would write a single driver for the series, and include code to handle the different models...

Your could write a common function library that would reside in the root directory of your driver. This would be in the form of a LVLIB, and you would call this from the individual drivers. This would limit your driver to the later versions of LabVIEW ( 8.0 and up for LVLIBs). If your customers are using < 8.0, this wouldn't work...

Another option would be writing an IVI based driver if you're looking to market these cards for languages other than LabVIEW . I would contact NI and ask them for their advice on this...

As a final note, you might want to watch http://openmeas.blogspot.com/' target="_blank">Brian Powell's BLOG. He's a NI software architect who specializes in instrumentation.

QUOTE(chrisdavis @ May 13 2007, 12:15 AM)

Michael, is there any way to upload a lot of images at one time?

I used the forums and gallery to upload multiple images at once...

Sorry to all for starting this off the wrong way. I was using the tool I knew (forums) instead of learning how to use Wiki. I was placing the images in a gallery using bulk upload, but even that supports only five files at a time. I thought of creating a Wiki with links to the images coming from the gallery, but... as crelf pointed out this will limit other people's ability to update/edit the gallery.

I've been taking a bit of time to look at how NI loaded and named their images on their web site for the HTML on-line manuals. Specifically, they used short names (8.3 DOS type naming) for most, and use a convention of 'C' as the first character for controls, 'I' for indicators, and 'funct', fun' or 'fn' as a suffix. This seems to be a good way to remember the names, and would make them easier to key in for those who would use them regularly. Their images are all GIFs, but I think PNG seems to be the accepted standard in the Wiki world...

QUOTE(LV Punk @ May 11 2007, 11:15 AM)

For the sake of continuity and to prevent confusion, anyone looking for artwork to use in postings or Wikis should look in the Block Diagram Images Wiki entry. I have deleted the images in my postings, and provided a Wiki link in their place.

Hi,

In OOP you also need the ability of encapsulation. Not just encapsulation of data, but also encapsulation of functionality. With your idea, how can I make two drivers (or in general objects) to two hardware devices, and choose which object to use at run time? (I know this can be done with dynamic references, but that's not oop!)

If you find a way to embed this into your idea, I think you'll end up with pretty much the same as LabVOOP.

Also in 5.3.2.3 you say: "Then the unbundle would let you see what was "initialized""

That seems easy at first. But how can LabVIEW determine if the wire is initialized at compile time (or worse: during edit time). Lets say we have a wire comming from a case. The false case does the initialization, the true case doesn't. LabVIEW can't know which case is used, so it cannot disable the unbundle elements correctly.

Some applies to class wires comming from sub vi's outputs, the connector pane (sub vi inputs), locals, globals, property nodes, variants, type casts or flattened strings.

How would you make a sub vi that acts on the class? The user can wire both uninitialized and initialized wires to the sub vi. during editting, the wire will most likelly be uninitialized.

Regards,

Wiebe.

Boolean Pallete

http://forums.lavag.org/index.php?act=attach&type=post&id=5822 http://forums.lavag.org/index.php?act=attach&type=post&id=5823 http://forums.lavag.org/index.php?act=attach&type=post&id=5824 http://forums.lavag.org/index.php?act=attach&type=post&id=5825

This thread contains entries for various LabVIEW block diagram constants, functions and VIs.

WOW! You can drag-and-drop an image from one post into a post editing session. No edit, or copying the URL. Ugh. Why didn't I try this before :headbang:

I'm willing to spend time into this :thumbup:

What would be the preferred file format? These will be fairly small files, so I don't think compression ratio difference will be significant. Michael had mentioned that GIF format was better for posts, but a quick web search regading Wiki images indicates that Wikis should use SVG or PNG.

QUOTE(JFM @ May 10 2007, 12:29 PM)

.

I'm not even sure I understand how it cannot be set to concatenate, if you have elements of two different dimensions (I don't have ).

/J

I noticed the same thing, I tried to get it to not concatenate, but could not duplicate. His avatar says 8.2 and that is the version I am using. How'd he do that?

QUOTE(Mike Ashe @ May 10 2007, 09:03 AM)

How do you propose to convey the desired information without wires?

I didn't want to do the guy's homework, so I was trying to give him a description of what to look for. If I could easily show him ( like ) then I would be closer to "teaching him to fish" without actually coding the whole thing.

The logical progression is an on-line graphical editor, but who's got the time to write that .

QUOTE(chrisdavis @ May 10 2007, 03:30 PM)

You have http://www.ni.com/trylabview/' target="_blank">this option, but it is probably more than most people want to wait for.

Indeed... nice solution, but really to long...

QUOTE(LV Punk @ May 10 2007, 01:30 PM)

The idea would be that one could enter something like :U32ctl: in a post and get a U32 control http://forums.lavag.org/index.php?act=attach&type=post&id=5800 or :bldarray: to get http://forums.lavag.org/index.php?act=attach&type=post&id=5801 as an emoticon.

Any thoughts? Comments?

I do love the idea ! that would be so much easier than opening LabVIEW, do a snippet, make a screen-shot and post it.

This would also let us post "labview code screenshots" form a computer without LabVIEW, I do not have LV installed on my computer at home.

Question is :" is that possible ?"

I was responding to a homework type post this morning. I wanted to help, but wasn't prepared to create an example, SnagIt, save as GIF, then upload.

I was sort of wishing I could have quickly placed a couple of BD function icons to help the poster. I then thought of the INI file WIKI and showing the datatype graphically http://forums.lavag.org/index.php?act=attach&type=post&id=5800. I realized that it might be useful to make the BD core functions and controls/indicators into emoticons for instruction/reference.

The idea would be that one could enter something like :U32ctl: in a post and get a U32 control http://forums.lavag.org/index.php?act=attach&type=post&id=5800 or :bldarray: to get http://forums.lavag.org/index.php?act=attach&type=post&id=5801 as an emoticon.

Any thoughts? Comments?

You already have a case that is controlled by a boolean (F/R). You now want to control left/right (I presume) and need to handle 4 possible cases. I'm not going to do it for you, but one thing you can do is:

add a second boolean control

combine the F/R and L/R control outputs into an array

convert the boolean array into a number

connect the numeric result to the case statement

set/add cases to the case statement for the values 0,1,2, and 3

(as a SeniorStudent, the boolean logic should be simple ) There are other ways to do this, but these are basic and useful functions anyone using LabVIEW needs to know.

p.s. Thnx 4 usn' str8 english in ur 2nd post

QUOTE(Bryan @ May 10 2007, 05:51 AM)

Welcome to the club. They haven't banned YouTube where I work yet, but I'm sure it's on the way.

I think our situation was a bandwidth/productivity problem in general. The blocks include the categories "Entertainment" like theonion.com, streaming media such as YouTube.com.

QUOTE(Bryan @ May 10 2007, 05:51 AM)

http://despair.com/pressure.html

At least despair.com isn't blocked (yet).

CITATION(JustinThomas @ May 10 2007, 09:24 AM)

I don't get the problem if I explicitly close the file. This means the problem is because I do not close the file before power off. Any help would be appreciated.

Hi Justin,

Why do you not want to close the file after each write ?

If you end up with very big log file, you may add maximum file length - eg : 10k lines - and create a new log file whenever the max size is reached. This would be quite easy if you turn your "write event to log file.vi" into a FGV that increment a counter each time you call it to log an event.

Hope this can help

QUOTE(SeniorStudent @ May 9 2007, 11:50 PM)

Hello,

I hav 2 cntrol 2 motors n a way that da user can choose wthr only one moves, or one moves followed by da 2nd..i hv the VI 4 cntrol'n 1 stpr motor. but i dint succeed 2 cntrl 2..im us'n 2 o/p lines of da LPT 4 da motor..

any ideas.? i need them to be contorlled sequantially with a slight time delay in between..

Give us more information that we can help you...

Sigh, my company recently installed Websense, no YouTube or MySpace anymore :thumbdown: and time at home is too precious...

QUOTE(Phaedrus @ May 5 2007, 10:49 AM)

I've used alien to convert .rpm to .deb for installing on Ubuntu, works fine for installing LabVIEW PDS.

Thanks. I found out about alien, but it's really hard to tell if that is the normal way to do it. I tried rpm2cpio without luck, and each try is can take hours (days) for a Linux beginner.

I've also considered rpm2tar.gz, but haven't got around it. All Linux stuff is outsourced for now, but eventually I'd like to know more about it.

BartPE is really not for us, unless I'm missing something here. We really need the system to be as cheap as possible, and with BartPE we should pay licence fee to M$. I know the Windows fee could be cheaper then the development cost in some cases. The aim is to make 1000 peaches, so we chose Linux.

Regards,

Wiebe

See Andrej's post on NI Forum

http://forums.ni.com/ni/board/message?boar...ssage.id=246133

You might try contacting Peter Blume at Bloomy Controls; I remembered seeing (and double-checked) Testand Corp. and Kenneth's name in the Acknowledgements section of Peter's book "The LabVIEW Style Book".

QUOTE(Val Brown @ May 7 2007, 06:29 AM)

...none of these methods actually reverse the entire control and, thus, leave the scale intact, ie oriented left to right.

If I understand you correctly, I think all you need to do is set the number on the right side of the scale to zero and the number on the left side to your desired scale. Drop a default fill control and double click on the 10 value, and type '0'. The left side number should change to 10.

As long as the right side value is less than the left side, the values you pass in don't require negating, and the scales should be settable by the operator. If you need to prevent the operator from reversing the direction, you might need to make an XControl.

Hello,

I'm wondering if anyone has ever used WDSL in LabVIEW for linux and windows to communicate with webservices. WDSL is a protocol based on XML and it uses SOAP binding. (WDSL Specification)

I'm looking for a LabVIEW implementation (G), or a shared library that is available in windows (.dll) and linux (.so).

A link in the right direction would be very appreciated.

Kind regards,

André Buurman

Carya Automatisering

The Netherlands.

I am working with Dave on this issue, and I know he doesn't read the fourm in the evening, so to help expedite things I will try to answer the questions.

QUOTE(xtaldaz @ May 3 2007, 07:27 PM)

What does the error say? I'm trying to see if it's an ActiveX error, and error in the driver, a LabVIEW error, or a syntax issue.

This is the error "Error -2147467259 occurred at Cmd Execute.vi->testdata.vi" and there is nothing under possible reasons.

QUOTE(xtaldaz @ May 3 2007, 07:27 PM)

Yes, several typical date formats work with single quotes.

QUOTE(xtaldaz @ May 3 2007, 07:27 PM)

If the column in the database table is defined as a Date time field the error occurs. It doesn't matter if you define the datatype in the parameters field as a string or date time, it fails. Only columns defined as date have a problem. The same code works in Access using the Micrsoft Jet 4.0 OLE DB Provider and in Sybase using the Sybase ASE OLE DB provider. Any help would be greatly appreciated.

Thanks,

Todd

I recently did my upgrade to LV 8.2.1 which included an upgrade to MAX 4.2, I immediately noticed one major change, no test panels. Instead of a floating display window when you hit the "Test" button, it is a split pane view with configuration in the bottom view and control or display information above.

While in some respects this may be desirable, to me they have taken away functionality. It would appear that I can only display the data as a graph, before I had the option to view the data as a chart, graph or value. If you have a task measuring DC levels on 32 channels, several of the values being identical, it is near impossible to get meaningful information in a graphical view.

Also, I often would have several test panels open at once, maybe toggle a couple of relays and view a couple of voltage channels, with the test panels now embedded in the upper pane of MAX this seems no longer possible.

I hope I am missing something, I called NI, they are getting back to me, I found nothing in the MAX help addressing this. I hope somebody has found a way to duplicate the functionality that existed in earlier versions, or if anybody can address why the change, I would like to hear from you.

QUOTE(Tomi Maila @ May 3 2007, 09:35 AM)

When you wire error out of an item to error in of another item, the items will be executed sequentially. So wire error cluster out from one of your loops and into another loop.

Note that you don't have to USE (connect) the error to anything inside the second loop. Just connecting it to the second loop defines the execution order. This is called creating an http://zone.ni.com/reference/en-XX/help/371361B-01/lvconcepts/block_diagram_data_flow/' target="_blank">artificial data dependancy and is a very useful technique. :thumbup: