MFC control with NI 6008

[SergeB]

Hello there and thank you in advance for any responses,

(FMA-2109 Datasheet Attached)

I have a mass flow controller (Omega FMA-A2109), which can be remotely controlled (0-5V signal) and you also read the flow output (0-5V or 4-20mA output). The controller also has potentiometer on it for the user to control the flow manually. To bypass the manual control, you need to make sure there is no jumper between pin #2&5 of the DB9 connector. My issue is that I can read the flow and control it manually no problem but I'm having trouble controlling the flow remotely. I'm using the NI USB 6008 to read and control the MFC. the manual says to connect pin #2 and 5 to your remote variable voltage source so i just connected to AO 0 and GND of my DAQ. When i change my analog output voltage (verified the voltage changing with DMM), the flow does not change. But i can still change the flow manually with the pot, which is weird. So i'm not sure what's going on. I also tried connecting a variable voltage power supply (instead of using the DAQ) and controlling the flow with that but no luck.

Am i missing something? Could this be an input/output impedance mismatch issue? Please advise, thanks!

-Serge

[Blokk]

"To bypass the manual control, you need to make sure there is no jumper between pin #2&5 of the DB9 connector."

Wrong. They are pins 5 & 9 regarding to the attached manual! This is either a mistypo in your text, or the source of your problem. If this is a mistypo, and you indeed removed pin between 5 & 9 pins, I would say you got a broken device. Specially since you tried an external voltgage source too, not only the USB6008...

[SergeB · Accepted solution]

Hi Blokk,

Thanks for pointing that out, it was a typo. I just found out i ordered the meter only version of the MFC, which makes sense why the pot worked but not the 0-5VDC control. How dumb of me >_<. Oh well, that's life. 

Should be FMA-A2209 and not FMA-A2109.

thanks again,

Serge

[mechatroniclover]

Hello everyone
I have bought a used "Unit UFC-1200A MFC" Mass Flow Controller, N2 gas, 2 SLM.
I have searched the whole net but I could not find any datasheet for this mass flow controller.
I am really confused!
Please help me.
Thank you

[Blokk]

You do not need data sheet, you have the pinout in your photo. It gives all necessary info...

[mechatroniclover]

Thank you for your answer.

So could you please tell me:
What is CASE GND, POWER COMMON, COMMON, SIGNAL COMMON pins? How should I connect them?
How much current will consume the MFC when I connect it to 15 volt power supply? (this will help me to select a proper power supply).

What is VALVE TEST PT?

Is the 0-5 VDC Iinput/output  linear with 0 to 2 SLM?

Thank you

[Blokk]

You need to power the mfc using a power supply capable to create a +-15VDC outputs (PSU should have 3 outputs). I think the mfc pulls max a few hundreds of mAmps current, so check the PSU if it can do so. Connect the PSU to the mfc with 3 cables as it makes sense (power common to the GND or "0" output of the PSU, the +15 to the +15VDC, the -15 output to the -15VDC of the mfc).
Signals:
Connect the signal inputs/outputs to your AIO device as described on the pinout picture...

About linearity: check the spec sheet, your model might have similar parameters as listed here:
https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.kephis.com/kephis/UNIT%25208500.pdf&...

[mechatroniclover]

Dear Blokk
Thank you for your nice information and the useful link.