mass flow controller FMA 5400 with LabView

[Nikolian]

Dear people!!!

I have a Mass Flow Controller (FMA 5400 from Omega) which will measure flow (l/min) which I will connect to my CB-68LP board and this to my DAQ-card 6024E. The outputs I will get from my Mass Flow Controller will be in voltage in the range of 0 to 5 V. There is two questions that I will like to ask:

1) How is it possible to translate those voltages into litters? I suppose I need to find the linear equations that are relating the voltages to flow. But it seems i can not find this information knowhere in the manual of the Mass Flow Controller. The only tip I have from the manual is:

"OUTPUT SIGNAL: Linear 0 to 5 VDC (1000 Ohms minimu load impedance) and 4 to 20 mA (0 to 500 Ohms loop resistance); 20mV peak to peak max noise for FAM 10, 50 and 100L/min and 100mV peak to peak max noise for FMA 200 500 and 1000 L/min"

2) Is it possible to control the Mass flow controler from LabView?

Thank you for your help

Alex

[vt92]

0 - 5V will correspond to the max flow output of the controller.  If it is a 2 liters/min MFC, then 5V = 2 Liters. 

You should be able to connect an analog output from the 6024E to the FMA 5400.  The analog voltage should also corresponed to the max output. 

See section 5.2 and 5.4 of the manual.  http://www.omega.com/Manuals/manualpdf/M2898.pdf

[Nikolian]

Yes this is it exactly thank you so much. The equation is litters = 40 * voltages. But I have another problem that you might be able to help me.

As you know I have my 6024E Daq card which has 15 analog inputs and 2 analog outputs. I am using 8 inputs (0 to 7 channel) to measure temperature and 4 inputs (8 to 11 channel) to measure pressure inside a gasifier. The channel 12 will be used to measured the input voltage from the mass flow stroller and those values will be added to my final datafile.

Now I will like to use one of the two outputs of my card to control the mass flow meter ( which again I think is related with the voltage). But I don't have any idea how to configure my .vi. I have attached the .vi I have build so maybe you can see better what I am trying to do.

I know that there is to many modules and they could be put into an array but at this moment this is not my concern. I have started to build the analog output part but I really can not see how I will continue this and included with all the rest modules.

Thank you

[Nikolian]

After some research I came up with this .vi. which I have attached

 
So the output 0 channel of my Daq card will be connected with my Mass Flow controler and I will include in the data flow control the litters we will like to pass ( using the equation litters/40 = Volt ). This will tell the mass flow control how much flow it should let.
 
And then by using my input 12 channel of my Daq Card I can do my data acquisition of the real flow.
 
Do you think that this .vi will work? Or we will need some additional modules?

[vt92]

Looks pretty good functionally. 

I would suggest:

• Adding a wait in the Analog output loop.  How quickly does it really need to update
• Consolidate some of your code into subvis
• The array index expands automatically, you don't need all those constants (0-15)
• Why are you dividing by 1 and adding a zero inside the lower loop?
• Your whole block diagram should fit on the screen without scrolling in both directions.

[vt92]

Here's a suggestion to consolidate your code:  (this is not the whole vi, just some of the code inside your while loop).