topic Re: Having trouble with simple test setting using case structure and boolean (new to labview) in LabVIEW

Having trouble with simple test setting using case structure and boolean (new to labview)

jetsfan123 — Wed, 25 May 2016 12:27:50 GMT

Hi, I have all of my hardware set up (DAQ, thermocouples in place, etc) and I am trying to run an experiment where I run current through circuit breakers for an hour on and an hour off continuously for lets say 8 total hours of testing. I want to take temperature readings every 2 minutes only when the current is running for that hour(30 samples/hr). Do I use case structures or booleans to contruct the VI? What is the set up for this?

Thanks in advance!!

Labview Rookie

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

RavensFan — Wed, 25 May 2016 12:51:20 GMT

Yes and Yes.

Have you taken the tutorials yet?

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

That is the best place to start. Until you are able to start programming something, I doubt we can help you.

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

jetsfan123 — Wed, 25 May 2016 13:07:54 GMT

Below is my code attempt. I have included a for loop and a wait until next ms multiple for the experiment. I am aware it is wrong and had went through the tutorials and am still struggling. Can one guide me in the right direction?

Thanks!!

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

crossrulz — Wed, 25 May 2016 13:24:25 GMT

I am sort of thinking out loud here for how to do this, so some thoughts may seem random...

Your loop should be a While loop, not a FOR loop.

Use a shift register to hold the state of the current. How are you controlling the supply current?

Use the Elapsed Time with the target time set for 1 hour (3600 seconds). When the Time Elapsed goes TRUE, invert your "applied curent" state.

Use a case structure. When False, do nothing. When TRUE, read your data and do whatever you want to do with it.

Likely need another shift register to tell how many hours you have ran (count Time Elapsed going TRUE). When your 8 hour are up (or however long you want to run), stop your loop.

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

jetsfan123 — Wed, 25 May 2016 13:54:38 GMT

Thanks for the input- I am controlling the current with a PLC. This is what I have so far. All I want to do is obtain the data and then export it to excel - not sure how to do that. Am I missing anything because it is not running.

Thanks!

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

RavensFan — Wed, 25 May 2016 15:08:23 GMT

Your code is inside out.

The while loop shold be the outside.

The case structure inside.

Elapsed time should be wired to the case selector.

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

johnbt29 — Fri, 27 May 2016 01:51:18 GMT

jetsfan,

Hope the attached file helps you in getting the task done...

-John

Re: Having trouble with simple test setting using case structure and boolean (new to labview)

Ekama — Fri, 27 May 2016 07:08:51 GMT

This is what I ussualy do to save data in excell. Os course, you need Excell installed in the PC.