Bronkhorst F201c mass flow controller using LabJack U3

[Shahab_06]

I want to create a Lab View program to control a bronkhorst mass flow controller. The communication is with Labjack U3. I need help creating the program. Can anyone please help??

[Blokk]

You did not give enough info. What is the Bronkhorst model, what kind of MFC? What interface is available for this MFC? It can be that, it has RS232 option, so you only need a serial port to control it. If it has only analog control/read options, you might use the LabJack device. What is the LabJack model you have?

edit: sorry, now  i see the model name of MFC is in the subject line 🙂

edit2: I think all of the submodels support RS232, so you do not need the LabJack to control and read flow data of the MFC. Just get a simple RS232-USB converter (models with FTDI chips are good usually), or a PC with a built-in serial port. You can download LabVIEW example VIs from Bronkhorst for RS232 communication.

Besides, contact Bronkhorts, you will need a special cable which gives power to the unit, and also gives you an RS232 connection cable...

edit3: check this out:

http://www.bronkhorst.com/en/downloads/labview/

[Shahab_06]

Thanks Blokk for your reply.

You're right, this model of MFC does not have any digital communication option. It's only analog. For this reason I need to convert analog to digital and Labjack U3 performs this task. The model is Labjack U3.

I'm supposed to control/read using these available equipments. Thanks again for your given link. I noticed the plug and play module but problem is the absence of RS232.

[Blokk]

Ok, clear. Check the spec sheet of the mfc first. You need to check the wiring first. Usually there is a power input, an analog input for flow setpoints, and analog output for monitoring actual flows, process values. When you have the required ranges, you can program the LabJack accordingly, to read actual flow and set the flow setpoint. Website of LabJack gives you LabVIEW drivers. Try to start in this way, and report back here if you get problems. I might have little time tomorrow to have a closer look...

[Shahab_06]

Hey Blokk, 

I've installed the LabJack drivers and able to read from the external supply. But I'm currently unable to write. For writing I know we've to connect the mass flow controller which I haven't done yet. But at least the LabJack pin to which the MFC will be connected should get the voltage. But I'm not getting the voltage at the pin.

What can I do now??

Thank You,

Shahab

[Blokk]

Attach your VI what you use to read and write voltages with the Labjack.

[Shahab_06]

The "AI voltage reading.vi" is for reading and it's working. The "write read.vi" is for reading and then writing, but it's not working.

Thank You

[Blokk]

I did not have time to go too deep into the driver subVIs, but I have downloaded the package. As I see you use some rather advanced raw subVIs, no idea why. I would try to use the simple example VIs shipped in the driver folder.

Since you can read AI from the device, I guess you managed to install the driver exe itself. After that, you need to download the following zip:

https://labjack.com/sites/default/files/LabVIEW_LJUD_2016_02_09.zip

Unzip this file, and place the created folder under your NI LabVIEW folder, under instr.lib folder! Restart LabVIEW. Now you have the palette for LabJack U3 also.

Find this menu place:

LabVIEW_LJUD --> Examples --> U3 --> Easy Functions --> U3 eDAC Example vi

Open this VI, and try to use it. Does it work?

[Shahab_06]

Thank You Blokk. Yeah it works. Your idea is really very helpful.