load displacement

[Alain_S]

Correct me id I'm wrong but I understood that you have 2 machines.

One with LV8.5 and another at the Instron tensile tester that can't handle LV.

Right? In that case you should make an installer on your LV machine that you can install on the Instron machine.

You can use the attached LV project file as a start.

Just change the path to the Instron.vi file and installer location and build the installer using the "Build All" button in the toolbar.

Since you use GPIB I checked the NI-488.2 2.5 in the "Additional Installers" part.

Good luck

[AlexDO]

Yes, this is the case, i have 2 computers, and the computer at the instron is very weak.

when you say change the path to the instron.vi file, i am looking at the project explorer and i see that the file in the drop down is the instron.vi. Is this the what you are talking about?...not quite sure what you mean. Also, i am unsure how to change the installer location. or by this do you mean just installing it on the other machine. and when i finish this, i assume build all creates the installer file which i just bring over to the new machine which will then run along with the instron.

thanks,

-Alex

[Alain_S]

When you right click the Instron.vi entry in the project and select Properties you get a window as in attached file SNAG-021.JPG. Look at the location, that's somewhere on my computer. You better remove that Instron.vi entry and drag your VI into the project.

You can change the installer location by unfolding the Build Specifications icon. You get an entry called Instron-Recorder, right-click that one and select Properties. In the Category\Product Information you can see the file selector called "Installer destination". Here again, a location somewhere on my computer. Change that also to somewhere on your computer.

Also don't forget to also change the ridiculous entries I've made 🙂

Once you've made the installer burn it on a CD and install it on the Instron computer just like any other software.

[AlexDO]

OK,

so I just decided to install labview on the crappy computer. Its working OK, and the instron is talking to the LabVIEW. But what i need to do now is figure out how to customize the sampling rate. If you have any tips on this, that would be great too.

Thanks,

-Alex

[Alain_S]

What do you mean by "customize the sampling rate"?

There's no timing in that vi, so it run's as fast as it can 🙂

Do you need more datapoints? Then you have to check what holds up the vi. Is it the GPIB write or GPIB read or ... ... ?

Do you need less datapoints? Then add a timing vi in the loop to hold the vi as needed.

While modifying the vi you could also improve the read from string as follow

You don't need tree times the same vi as one can do the job 🙂

That is of course if there's a dedicated character to seperate the three data points read.

I used a "*" in that exemple.

[AlexDO]

yea, all i need is a way to write a data file...to excel most likely, as well as set a sampling rate. I'm not sure what tree times are, or what a read from string is.

but if there is a way to do this, that would be great. Like i said, i am very new at this.

Thanks,

-Alex

[Alain_S]

 

• A) Can you post what comes out of the GPIB read vi? Basically the contents of the "Read Data" indicator after one GPIB read.
  
  
• B) What information do you need in the file? All three data from the Instron or not, in what order? Maybe relative test time in the first column? Other information like sample ID, product Info, machine operator, ... ... ...
  You better make one Excel sheet manually and post it here so that we know what you need.
  Should file name be generated automatically from some provided inputs or should the operator enter something after a tensile test is done?
  
  
• C) Sampling rate! What are the limitations of the Instron? How fast can you retrieve data now? What range of sampling rate do you need?
  
  
• D) What information do the operator enter before a test is started? Sample ID, sampling rate, ... ...
  
  
• E) I suppose you will make an EXE file once the program is ok, right? Then you need to review the whole setup of the code.

So, please answer all the above questions so that we know the requirements of the program. Once they are known, one can start programming.

In the mean time I'll start a kind of framework for this application.

[Alain_S]

Well, here's the first shot 🙂

I added a "Simulation" button so that you can check functionalities without the Instron machine. The code then generates some fake data 🙂

I also used some Open G vi's because...........................I like to use them & they are very good 🙂 🙂

So you will have to download and install the Open G library. How to do? Read here

Nothing is foreseen to save data to Excel yet.

Error handling is very basic now, can be improved.

Allow me to explain some things:

• The program structure is based on a state machine.
• As long as the user does nothing and recording isn't on, the code is doing...........nothing, except running through the Idle state  
• As soon as the user modify a control, the code take some actions through the Event structure in the Idle state.
• All program variables are in the "HighWire" cluster. That way you need only one shift register to handle all your variables and you don't need local variables or property nodes.
  That cluster contains another cluster named "Settings", all the data from that cluster is stored in a file just before closing the VI and recalled when opening the VI. That way you start the program like you stopped it last time.
  So if you want a variable to be stored when stopping the program, put in the "Settings" cluster. A variable that doesn't need to be saved belongs in the other cluster or any new one.
• Once the "Start recording" button is pressed, the code loops endlessly between the "Idle" and "Get One Reading" states. The "Quit" button is then disabled, you can't stop the code. Once you stopped recording, you can quit the program.

Questions?

Please ask

[AlexDO]

so what i did is add an output to the original .vi. I can get stroke and load from it. But i still cannot program the sampling rate, or plot the time along with the load and stroke data. If i can do this, then i am all set.

I think this new .vi that you have is a little more advanced than what I am looking to do.

Thanks

-Alex

[Alain_S]

"a little" yes, but it does it all 🙂

I put a relative test time functionality in the "new" code by means of the "Tick count" vi. Save actual tick at te start of the test, add each tick count with every reading and when test is done subtract the original value from all other ones, see "cmdToExcel" event.

The sampling rate need the hold the GPIB Read/Write for a certain amount of time.

So you can use some "Delay" function vi's or use the OpenG "Periodic Trigger" vi. It does it all for you 🙂

Now you will put some numbers in an Excel sheet, how will you keep track of what they represent.

I mean, if in six months from now someone ask you for some sample data, how will you know what measurement file to dig up?