topic Re: dataflow - problem in LabVIEW

dataflow - problem

nkritsch — Fri, 05 Sep 2014 13:29:34 GMT

I have an Dataflow Problem.

I wish that in the 2nd loop it would be this dataflow:

-DAQ Assistant 2

- Time Delay

- DAQ Assistant 1

- Array 3 split in 2 arrays and make new array

- then the 2 Graphes should write.

How can i solve it best.

Need i do Sub VIs or can i somethink make an priorisation. It would be great.

And a second question.

When i am starting my program a 2nd time i need to clear Array 3.

Why is it so?

i think i create a new Array 3 before the Loops.

Re: dataflow - problem

JÞB — Fri, 05 Sep 2014 13:35:45 GMT

Just wire the error out of DAQ Assistant 2 to time delay error in, then wire time delay error out to DAQ Assistant 1 error in.

Yup those error chains are really handy And wireing those errors will improve your code functionality in the event something is wrong with the hardware.

Re: dataflow - problem

RavensFan — Fri, 05 Sep 2014 13:38:39 GMT

Use the error wire from between the daq assistants and the delay function to determine the order of execution.

Don't use local variables. Array 3 should be maintained in a shift register on your outer For Loop.

Insert into Array is almost always the wrong function to use. You should be using Build Array instead.

I would recommend looking at the online LabVIEW tutorials
LabVIEW Introduction Course - Three Hours
LabVIEW Introduction Course - Six Hours

Re: dataflow - problem

nkritsch — Mon, 08 Sep 2014 07:26:52 GMT

when i use shift registers instead of the local variables:
I dont need the array3 any more...i can shift the output of "build array".

But how can i write and read in an array.

because its allways control or indicator.

so if i use it i cant update the array any more or?

edit: i cant use Build array because i dont know how many elements that array should have. its dynamic

Re: dataflow - problem

RavensFan — Mon, 08 Sep 2014 13:17:29 GMT

nkritsch wrote:

when i use shift registers instead of the local variables:
I dont need the array3 any more...i can shift the output of "build array".

But how can i write and read in an array.

because its allways control or indicator.

so if i use it i cant update the array any more or?

edit: i cant use Build array because i dont know how many elements that array should have. its dynamic

I don't understand what you are trying to say in the first paragraph.

Yes. You can use Build Array. You can put a new element at either the beginning or an of an existing array.

See attached.