lenny wintfeld

I was able to fix the problem, though I'm not exactly sure why what I did fixed it. I post what I did here in the hope that someone else will find it useful at some point. 1. My computer had MSXML 6 installed in it. I downloaded and installed MSXML4 Service Pack 3 from the MS web site. This installs in parallel with MSXML6. Shutting down and reloading LabVIEW and then loading the sample program was then enough to eliminate about 70% of the errors. 2. The remaining dependent vi's with errors were fixed by a) going to each of the MSXML Invoke Nodes that had broken wires leading in or out of them in each vi with errors, b) selecting a method or property that is shown on the invoke node (which caused LabVIEW to make that node a lighter color and also caused LabVIEW to display a list of all valid methods/properties), c) selecting from the list the exact same attribute or property. Doing this for only one property/attribute fixed all bad wires on that particular Invoke node! I'm not sure why doing this fixed the problem. I speculate that it caused LabVIEW to re-load the reference to the node from a different typelib on my computer. But that's for somone much more knowledgeable than myself to answer. Thanks to forum participants who helped in the past. I hope this will aid somone, some time. Lenny Wintfeld

Hi I'd like to use the MSXML15 libraries from sourceforge to parse an XML configuration file, but so far, no luck. I tried dropping the sample vi that came with the MSXML15 package "Database editor.vi" onto a blank block diagram, but it generates tons of errors. The example's block diagram is clean, but vi's that it uses have lots of error messages in them. I can provide specific examples if it would help. Most (possibly all) of the errors are because of type mismatches on wires that connect XML invoke node methods or properties with Labview objects. The methods/properties invariably are of type void and the LabVIEW objects have some other (evidently) incompatible type. I suspect that this either has to do with my version of LabVIEW (8.0) or with a LabVIEW setup option. The reason is, I have the same problem with the very nice example program posted here by Randy on 7/19/06. His vi is MSXML_save_XML.vi and its block diagram yields similar type mismatches. I also tried using DEMO_XML_File_Read.zip by jlokanis from his post here of 8/25/08, but it is Labview 8.5 specific and 8.0 won't load it. Can someone give me some hints on how to get the sample programs to run? And more generally, are there some resources I can look at that would help me get at MSXML methods directly? I've done quite a bit of DOM parser access to XML in Java and while it's tedious to do, you can accomplish quite a bit with it. Any advice greatly appreciated! Lenny Wintfeld

Thanks for the reply! I was a bit faked out by the contents of the context help for the enum ring that goes into the case. -Lenny

Hi, I've been going through the tutorial "Developing Labview Plug and Play Instrument Drivers" at zone.ni.com/devzone/cda/tut/p/id/3271. The tutorial recommended using the icon library Icon256.vi as a good source for starter icons for the various vi's that make up an instrument driver. I've been trying to undersand this vi for most of the afternoon and I'm still stumped. My copy of the vi is in \Program Files\National Instruments\Labview 8.0\examples\instr\insticon.llb. You can find s copy in a similar location on your machine. The block diagram has an enum ring control wired into a case statement. Each case has text describing icon subcategories and icons and no executable objects. The Front Panel shows a black triangle with some instruction text and if I double click the enum control on the block diagram, the ring shows up behind the triangle on the block diagram. When I run this VI, it executes and exits in a fraction of a second. This VI evidently IS meant to be run; if you turn on context help and click on the enum ring, there's an explanation of how it was modified so the vi could be instantiated in Labview 8.x. The questions I have not been able to puzzle out on my own are: 1. This is not a sub-vi. It has no interface terminals. But it also has nothing to keep it running (like a timed while loop) So what is it? 2. What is the purpose of (constant) icons on the pages of the case statement ? Evidently they're meant to show up on the Front Panel, but how? And how did the programmer put the icons into the case pages to begin with? 3. Is the category header text thats in the case statement pages simply comment text without boxes around it or some "object"? 4. Is this vi meant to be run as a sub-vi? If so how would it be used? I've only been using this language for a couple of weeks so far, so please forgive me if these questions seem a little basic. Thanks in advance for any help. Lenny Wintfeld

Thanks for your replies! Just to be cautious I moved the ...\Blah123 directory to the desktop instead of deleting it. Blah123.vi does show up on the recent files list of the Getting Started window and it also shows up in Functions Palette -> Instrument I/O -> Instr Drivers. But after Labview is completely shut down and restarted, it disappears from both. I shoulda tried it out on my own. Duh! BTW LV_FPGA_SE's second method seems much more elegant. I have not seen it anywhere in Labview 8.0, though :-) -Lenny Wintfeld

Hi, I've been reading the very helpful "Developing LabVIEW Plug and Play Instrument Drivers" tutorial at zone.ni.com/devzone/cda/tut/p/id/3271. About half way through, it has a step-by-step section on "Using the Instrument Driver Wizard". I played along as I read this section and ended up creating a skeleton instrument driver Project at \Program Files\National Instruments\LabVIEW8.0\instr.lib\Blah123 and its subdirectories. I'd like to eventually (like right after I finish the tutorial) delete this bogus Project. I've looked for a way to delete a whole project and so far, I can't find out how to do this using LabVIEW. So my questions are: 1. Is there a "conventional" way to use LabVIEW to delete a whole project? 2. If not, can I just delete the ...\Blah123 subdirectory in Windows Explorer? Or will there be dangling references to this project stored eleswhere in LabVIEW? Thanks in advance for any advice. Lenny Wintfeld

Thanks *VERY* much! All your replies were right on. I tried each of the methods you described and learned a lot from that. Also tried disconnecting the Ctl object in the TRUE case and then creating a constant at the input shift register. Result was constant array with no type and a "void" wire since the compiler didn't know the type of connection ... all of which was expected. One thing I'll have to get used to is that the program retains state between successive runs. There isn't a clear distinction between the launcher and the debugger. Anyway thanks again. I'm sure I'll be back with more things I can't figure out. Lenny Wintfeld QUOTE (jdunham @ Dec 17 2008, 06:15 PM)

Hi, I've been teaching myself labview using Travis/Kring's "Labview for Everyone" and I have been making excellent progress on my own so far. I'm stuck, though, with one of the example VI's: "Disable All Controls While Busy.vi" from chapter 15. It's attached along with my version "Disable all while run.vi". The example uses what appears to be a reference to an array of generic control to intialize the shift register in the first frame of the flat sequence structure. I have been unable to re-create that initializer object. If you look at my version of the code, you'll see that I tried to do an equivalent initializer as a class specifier constant and set it to "Control" using popups: Select VI Server Class->Generic->GObject->Control->Control. This object is wired to a "build array" object. If I wire these to the shift register and run the VI, the third frame generates "Error 1055 occurred at Property Node in Disable all while run.vi" with a reason of "Object reference is invalid". My questions are: 1. How do I create the intialization object shown in the "Labview for Everyone" example program. And as an aside, how would I get labview to describe that "thing" to me? 2. The object I created has the same type as the "Labview for Everyone" object (both are a "1D array of Control Refnum"). But based on the error message, mine has nothing that it refers to. What does the "Labwview for Everyone" object refer to? 3. In my version of the progam with the object that causes the problem not wired into the shift register at all (e.g. just "floating") the program runs just fine! Am I just lucking out with an unitialized shif register? If not, what is the purpose of the initialization object? Thanks in advance for any advice? Lenny Wintfeld