Control mass flow controller using USB 3105 (measurement computing)

[achimost]

Hi all, 

Currently, we are using USB 3105 measurement computing instead of Ni-DAQ/module card to send the analog outputs to alicat mass flow controller .

I am quite new with labview programming so i do not know how to convert the voltage to the flowrate and send it to MFC. I know the linearly scale but i do not know how to programe it in labview.  

Initially, i need to connect 2 mass flow controller to 2 channel of the USB and control flowrate in conditions: Flowrate of MFC1+ Flowrate of MFC2 = 25 m/min (~2.5V)

I tried to look up googling and youtube. Unfortunately, most of the instructions are using Ni-DAQ card.

Note: We do not want to purchase for RS232/485 connection so using labview(2012 version) is the must choice.

Hope to get a help from you.

Thanks

[achimost]

In other words, i need to help an example (picture/video) or idea how to send 2 analog output signals (in condition: V1+V2 = 2.5) to multiple channel. 

[yamadj]

Hello achimost,

I took a look at your VI but it seems to be missing some VI's. It seems as though you might be using a LabVIEW driver for you application. I looked for it on the instrument driver network but couldn't find it.

Could you possibly post a link to that driver as well?

In addition, it seems like it is pretty similar to the DAQmx driver calls and the code looks pretty simple so I don't know if your program is wrong, or possibly it may be a driver thing.

If you think it's possibly the driver, you may want to reach out to the device manufacturer who developed the device driver. In addition, they may also have examples as well which are usually included in device drivers from third party devices.

[achimost]

Hi Jordan,

Attached is the picture of my programming. This is the link of the product: http://www.mccdaq.com/usb-data-acquisition/USB-3105.aspx

Unfortunately, to get the driver of this product in Labview, you must to recognize it hardware by using instacal first.

The programme that i made was working with 1 channel and 1 sample. It is simple send the voltage and linearly scale to the flowrate of the massflow controller.

Now, i just want to send voltages to n channel and n sample. Specifically, 2 channels in condition: voltage 1 + voltage 2 = 2.5V.  

Thanks

[yamadj]

Thanks for the update,

I'm happy to help but, I'm really unsure of how those VI's that you have work. Again since they are third-party you would need to talk to whomever developed those VI's? have you spoken to "Measurement Computing" yet? What did they have to say about their drivers?

[achimost]

Hi

This is the response from Measurement computing: 
That is question that is specific to LabVIEW, and is unrelated to our product.  LabVIEW is an expensive and powerful programming language, that we do not sell.  You will need to seek help from whomever sells/supports LabVIEW in your area.....

There has a lot of support information from internet souces: How to send different analog signals to n channel and n sample. Unfortunately, most of them used NI card.

The programme (that i did) was worked for only one channel and one sample.  

[achimost]

I have found the solution. Look at the attached file. I knew it's quite "stupid" and may be it had some error.

Test has been done with 2 mass flowcontroller (50ml/min).

By the way, yamadi, could you upload the simple pid.vi (labview 2012) since i did not have the pid tool kit in my labview? 

[yamadj]

Hello Achimost,

I found this example in the LabVIEW Example Finder and it doesn't seem to use any special VI's.

If you want to check other examples out, check out the Example Finder - http://www.ni.com/getting-started/labview-basics/examples

You should be able to replace the plant in this example with the I/O from your applcation.

[achimost]

Could you please upload this file in 2012 version as i can not open it?

Thanks

[yamadj · Accepted solution]

Hope this helps!