Developing a Control VI for Omega mass flow controller

[Lashafih]

Hi,

First of all, I am new to LabVIEW but I am trying to develop a VI to control an Omega 2600A series mass flow controller in LabVIEW using DAQ Assistant. The mass flow controller is not receiving signal with the VI I built. I have a strong feeling that my wiring or DAQ Assitant coding is wrong but don't know how to go about resolving this. I need somebody to kindly help look into this.

Attached is the VI I built

Regards,

lashafih 

[timtamslam]

Hey lashafih, 

I am trying to develop a VI to control an Omega 2600A series mass flow controller in LabVIEW using DAQ Assistant

Can you clarify your goal, please? Are you trying to send a control signal to the device or are you just interested in reading an output signal that the device is producing? 

Can you also clarify which output mode you have for your 2600A? It can output as RS232/RS485, 0-5Vdc, or 4-20 mA depending on which configuration you have. 

The VI you have attached is writing a continuous Voltage output to a PCI-6221. This is different then what I would have expected. If you're looking to acquire a signal from the 2600A you need to use an input task.

[Lashafih]

Hi Timothy,

Goal: I am trying to send a control signal to the device.

(b) The output mode for the 2600A is 0-5Vdc,and the set point input signal is also 0-5Vdc.

(c) The VI I attached was using the 9263 C-series NI-module to send the control signal though not so sure if I did the right thing.

Please see attached for the signal connection for the Omega FMA 2600A.

Thanks,

Lashafih 

[timtamslam]

(c) The VI I attached was using the 9263 C-series NI-module to send the control signal though not so sure if I did the right thing.

Thanks for clarifying. The confusion on my part was the 6221 populated from my computer and I couldn't see which was in your setup. Sorry about that.

I don't really use (or recommend) DAQ assistant configurations so it's tough for me to say whether you have wired it up correctly or not. From what I can see it seems correctly configured though. 

When you run the VI, does it continue to run? 

Have you checked to make sure there is no error returned? (Probe the error output before you run the VI)

If the VI is running, did you validate with a multimeter that the correct value is generated?

If you have already tested a multimeter, which pins are you probing?

I would actually recommend trying the example VI, "Voltage - Continuous Output.vi" which uses the daqmx VI's directly instead of the DAQ assistant. You can find the example VI in the Example Finder.

Example Finder can be found at Help>>Find Examples...

Then navigate to

Hardware Input and Output >> DAQmx >> Analog Output >> Voltage Continuous Output.vi

Debugging the issue will be a lot easier with this VI.

[timtamslam]

Oh, also. You can always try out Test Panels in MAX. That would give you a quick way of determining that your hardware is functioning correctly without needing to use LabVIEW. 

Using Test Panels in Measurement & Automation Explorer for Devices Supported by NI-DAQmx

http://www.ni.com/tutorial/4638/en/

[Lashafih]

Hi Timothy,

Thanks for the feedback and sorry for replying late. When I run my VI, it runs both nothing the noticed on the device (MFC) I am trying to control.

I have also tested my hardware functionality, it functions well.

If I want to vary my output voltage using labVIEW having used DAQmx functions, how do I vary it between 0 - 5 Vdc? 

Thanks,

Lashafih

[timtamslam · Accepted solution]

You would wire the Analog Output value that you want to the DAQmx Write.vi. You could select the value you want using a Knob just the same way you have it wired in your previous example.

[Sman29]

Hello lashafih,

Sorry to thread jack. I am trying to do something similar to you and I'm having the same issues as you are. However, I cannot open your VI. Can you or someone post it to be compatible with LabVIEW 2013 please?

Thanks,

SM

[timtamslam]

Here is the VI saved for 2009. It should open in your 2013 environment. 

[Sman29]

Thanks!