Attribute nodes

[Marce]

Hi,

I'm new to LabView 7.1 after having tried LabView for a short time. Can anyone tell me where the attribute nodes go? How are they called now?

Thanks,

Marcelo

[chilly_charly]

They became "Property" nodes...

[THailey3]

Hi Marce!

Perfect answer, Chilly Charly. Just like CC said, Property Nodes replaced Attribute Nodes as of LabVIEW 6.0. However, it was more than just a name change. There are more features (such as error handling) and functionality with Property Nodes. For more information on the differences between Property Nodes and Attribute Nodes, refer to the KB below:
http://digital.ni.com/public.nsf/websearch/16CC3ED84A6A111F86256937006D199A?OpenDocument

Note: To obtain a property node for any control or indicator on the front panel, right click on the control or indicator and choose Create->Property Node (you can do this from both the front panel or block diagram). Click on the property and it will bring up the list of possible properties for the associated control/indicator.

Hope this helps!

Travis H.
National Instruments

[Marce]

Thanks for the answer. After your message I've seen in the manual about the Property Nodes. One of the disadvantages of the old attribute nodes is that you couldn't treat them, when they belong to array/cluster elements, within a for loop. You had to create one node for each element and change the property within a Case structure. I hope there's a way to change the properties in a For loop now. If you have any comment or pointer, I'd appreciate.

Thanks much,

Marcelo

[THailey3]

Hi Marce!

I'm not sure I am understanding you perfectly. However, let me use a cluster example to try to explain this a bit further. I have attached the Cluster.VI to illustrate this. You can index each of the individual controls in the cluster (via its reference) to gain access to its value, or you can bundle up the desired values and send a value to the entire cluster.

Hopefully this will clarify some of your concerns. If not, try to explain your situation more in detail (posting a simple VI would help to do this).

Hope this helps!

Travis H.

[Marce]

Thanks for the answer.

If I understand right your example, you change the values of the Cluster elements and bundle them into a cluster. I need to do the same with the properties. I don't see how I could bundle properties of the elements in the cluster.

I'm attaching a small example of my problem. Just a short explanation of how it works. With setting a value in ID and pressing Main I make the right element in the Cluster to get TRUE value and blink. I give the TRUE value withinh the For Loop and that's right. My problem is that in order to make one element to blink, I have to crate a Case structure and create a property node for each of the elements in the cluster. That's a big problem if I have tens of Leds in the cluster. What I need is a why to change the blinking property of the Leds within a For Loop, the same way that I chage their valur.

Thanks,

Marcelo

[THailey3]

Hi Marce!

I do see exactly what you are referring to. Your simple VI along with the description really helped to clarify the issue. To answer your question, there IS a way to accomplish what you are trying to do. To do so, you will need to acquire a reference to each of your controls. You can then build an array from these references. Then, you can use a For Loop with indexing enabled to send a single control reference to a generic property node. This will allow you to use a for loop to cycle through each of the controls and set the properties accordingly. You will see exactly how to do this from the attached VI (written in LabVIEW 7.0).

I hope this helps!

Travis H.
National Instruments

[Marce]

Hi Travs,

Thanks for the answer and attached message. I'll try it later today. It sounds good and I'll also use it to learn about references, which I haven't used until now.

Marce

[Marce]

Travs,

It took me a few days but finally I've tested your Vi (blinker70). It solved my problem and I also found a way that avoid the need to create manually the array of references so it's even easier to work when you have many booleans. I'm attaching blinker71.vi that is your original program with a small change. Please feel free to comment.

Thanks,

Marce

[altenbach]

Marce

Looks good.

One problem is the fact that you are constantly calling these property nodes thousands of times a second, pegging the cpu at 100% and starving all other running processes (put an indicator on the iteration terminal to see). Property nodes are relatively expensive and should only be called if actually needed. I'd suggest an event structure, it's more gentle on resources. (See attached quick modification, LV7.1)