topic Re: I need to help in LabVIEW

I need to help

erdmirci — Thu, 23 Aug 2012 11:20:34 GMT

Hi, I'm trying to write a programme about labview but I have a problem. There is a "example" vi in attachment. When I run the programme which is green in the example vi , it does not any response outside, but it runs in itself. I want to take continuingly data from device and I want to use outside. How can I solve this problem?

Re: I need to help

Frabto — Thu, 23 Aug 2012 11:38:55 GMT

Use Shift Reg to store data.

For parallel ACQ and data manupliation use Queues to Transfer data .

This example from community can be helpful

Re: I need to help

erdmirci — Thu, 23 Aug 2012 11:44:42 GMT

Thank you for your attention but I'm afraid that it is so complicated for me because my labview level is intermediate. Is there any easier method :).

Re: I need to help

Frabto — Thu, 23 Aug 2012 11:50:10 GMT

What are you expecting ? You want the complete data at the end or the live data to be used elsewhere in the code ?

Re: I need to help

Frabto — Thu, 23 Aug 2012 11:52:37 GMT

If you need live dat easiest way is to create local varaible and use it.( But local variable is memory costly. Better learn to use better ways of programming)

If complete data at the end is required use shift register as shown below

Re: I need to help

erdmirci — Thu, 23 Aug 2012 12:00:10 GMT

When I run the vi, I want to collect all data. But in the example, data does not came to the part of DC. In my opinion, there is a loop inside loop for that reason it doesn't work. If I save for this case, may be it can work.

Re: I need to help

Frabto — Thu, 23 Aug 2012 12:13:52 GMT

In that case you need to pass reference of the Front panel control to that subvi and update the value using property node

Re: I need to help

smercurio_fc — Thu, 23 Aug 2012 13:23:35 GMT

Your question, intent, and VI are not clear. The VI you uploaded contains a single loop that calls a subVI that you did not include. I don't know what you mean by "green" in the example. You also did not indicate how you are collecting this data. It appears to be via a serial connection. The Build Array method shown in nijams's example is not necessarily a good method since it continously builds an array, which causes memory thrashing.

Re: I need to help

Mark_Yedinak — Thu, 23 Aug 2012 14:48:24 GMT

@nijams wrote:

In that case you need to pass reference of the Front panel control to that subvi and update the value using property node

While this will work I would recommend an architecture that decouples the data acquisition/processing from the UI. It is a much more modular approach and easier to maintain. Once you start passing control references around your code becomes tightly coupled and it is much more difficult to reuse code in multiple applications. For passing data from the processing to the UI queues, notifiers or user events are the recommended methods.

As for the comment that queues are too advanced it is generally better to take the time and learn how to use the tools available rather than trying to make things fit using the most basic techniques.

Re: I need to help

erdmirci — Thu, 23 Aug 2012 16:16:12 GMT

In attachment there are all progremmes. First of all I chose Hinds_Signaloc_Ver1_1 vi and then chose Hinds_LockIn_Example_Streaming sub vi. I used this sub vi in the example file. Actually as a matter of fact, I need to solution rather than recomendation "quickly". Meantime I'll use another vi programme the example file this is trying, if it runs properly, I can use it. I think the problem is clear now :). Again thank you guys for your help.

Re: I need to help

Dennis_Knutson — Thu, 23 Aug 2012 16:51:04 GMT

What is not at all clear is why you stuck a perfectly fine example inside your own while loop and created this mess. Why not simply run the subVI all by itself? Otherwise, you are going to have to make quite a few modifications to the subVI and I suspect you have no clue how the subVI works.

Re: I need to help

altenbach — Thu, 23 Aug 2012 18:00:40 GMT

@erdmirci wrote:

Thank you for your attention but I'm afraid that it is so complicated for me because my labview level is intermediate.

On what scale is this "intermediate"?

Re: I need to help

RavensFan — Fri, 24 Aug 2012 02:35:58 GMT

@altenbach wrote:

@erdmirci wrote:

Thank you for your attention but I'm afraid that it is so complicated for me because my labview level is intermediate.

On what scale is this "intermediate"?

Maybe he meant "indeterminate".