Where to put communication with NI USB-6212

[JÞB]

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@Michael.Koppelgaard wrote:

I think I will buy 2 NI USB-6210, since I need 3 maybe 4 digetal input for 2-3 valves and 1 pump.

The sampling rate is lower 250 kS/s , instead of 400, but I guess the will be okay.

Am I right?

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Price vs Cost.  Buying "Extra" hardware that "Costs" a bit more has a far cheaper "Price" than trying to force the hardware to be used in a way it was not intended because of the savings in development time!  

I have worked projects where the "Bean counters" said "Buy This Device" because it was $xxx.xx dolors cheaper.  Then I spent a few hours developing a LabVIEW P-n-P Driver for the device since the available one was grossly flawed!  The other option had a nice driver.   At my hourly rate they lost a lot of potential profit on the project because of that choice. 

[Michael.Koppelgaard]

I’m also very happy for the advice you gave med buying extra hardware 

[Blokk · Accepted solution]

I attached the example project as a zip file, version is LV 2014. Unzip it, and check how it works. Right now the lvlib is designed to work with 6 digital outputs, and the default setting for the AI is to DAQ 12 channels.

If you get a second USB hardware, half the AI and DO channels. I also put an example main VI into the project so you can see how to use the VIs:

I just programmed the resource module to use "on demand" data acqusition from the analog inputs, so use software timing in your loops when you use these subVIs (as i did in the example VI in the project).

The 4 public methods in the lvlib are:

1. Init hardware
2. Sample a single double from all 12 channels
3. Set the logical level of the specified digital output line
4. Close resources, release hardware. 

edit: slight mistake with the second digital output level 🙂 Modify it in the zipped file! 🙂

[Michael.Koppelgaard]

I haven’t had a single minute today to look at your code and might not have it before Tuesday I’m afraid 

[Michael.Koppelgaard]

This is really great!!!   Well organized I can see that. I’m not sure, I understand everything jet, but I will certainly try my best to understand and will also of course use it.  I will try to correct my stateMashine next week and build your AE into it.

I hope I may return with the new code and let you (or somebody else, review it) for further corrections. Hope I’ll do better this time.

[Michael.Koppelgaard]

I have a question

I tried to build in your “set DO” and “Read” sub vi’s.

But when I do that, I get an error even though, I have run the init-vi beforehand.

What can be the reason?

[Blokk]

No idea, unless you show your whole VI with all the functions (Init, Read, etc...). Are you sure the Init happens BEFORE the Read?

If you make a test VI, like my snippet above a few posts before, does it produce error too?

[Michael.Koppelgaard]

I think you can pretty easy produce the error yourself. And I made an example in the 2 snippets attached. Very simple.

I had my LabVIEW trainer to look at the error, and he was puzzled and couldn’t explain the error. He had to think.

I checked that the resource module in your vi’s were the same and it was.

[Michael.Koppelgaard]

[Blokk]

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@Michael.Koppelgaard wrote:

I think you can pretty easy produce the error yourself.

I can setup a virtual DAQmx device, and I will test it. I come back when I tested it.

And I made an example in the 2 snippets attached. Very simple.

No. You showed the two subVIs only. You did not show how you use my subVIs!!

I had my LabVIEW trainer to look at the error, and he was puzzled and couldn’t explain the error. He had to think.

Still thinking? 🙂

I checked that the resource module in your vi’s were the same and it was.

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