Questions about example program "Icon265.vi"

[lenny wintfeld]

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

[Rolf Kalbermatter]

QUOTE (lenny wintfeld @ Dec 29 2008, 04:53 PM)

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

Basically it is meant as a library of template icons. You select the icon of your choice, then go to Edit->Copy or press Ctrl-C, then go to the icon editor for your own VI where you want to use this icon as a base and in there you make a Ctrl-V or Edit->Paste. Now you can start to customize your icon the way you want it such as adding the Instrument Prefix.

The Icon256.vi in itself has absolutely no runtime operation at all and is not meant to have one either.

Rolf Kalbermatter

[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