07-02-2012 01:18 PM
I need your help
We have two test stations. Each station has two Brooks mass flow controllers. We like to connect MFC with one Brooks 0254 4-channel secondary electronics module then communicating with Labview
I am not sure if we can share one Brooks 0254 secondary electronics module with two test station since 0254 module has four channels to connect with MFC.
The concern is if I run labview program for each station at the same time to collect flow rate data, will both labview programs will work well or not?
07-03-2012 10:28 AM
I do not see any reason why this should not work provided you have the most up to date drivers installed for all of your devices. If you can give us any more information about your system we can assist you further.
07-03-2012 01:53 PM
Thank you for your answer,
Basically we have two systems controlled by two labview program. each system use two MFCs, which connected the same 254 module.
So my system should work well if we use one PC to control our two systems, right?
For MFC, If I donot plan to use 0254 secondary controller, I can directly use labview to communicate with Brooks MFC (0-5V analog output ) using external DAQ card NI6008, right?
07-03-2012 03:54 PM
I see no issue with this system with the one PC and the NI-6008.
If you have any other questions feel free to contact us through the forums or 1-866-ASK-MYNI.
07-04-2012 12:43 PM
Friend, Thank you for your answer. I looked at MFC from Brooks again. They told me their MFC has RS 485 based HART procol. In this case, I can directly communicate MFC with RS 485 of PC. and I donot need a NI6008, right?
07-04-2012 05:57 PM
Back to my original question for Brooks 0254
If I use two labview programs sharing one Brooks 254. It means two labview program use the same com port. I think win32 does not allow one com port is used at the same time by two program. right?
07-06-2012 11:06 AM
you are absolutely correct on both accounts. If the PC has an RS-485 port or adaptor you can communicate directly to the port from the PC using LabVIEW VISA drivers. If you plan on running two devices continuously from the same PC you will need need two ports to easily communicate between two separate devices. Hope that clears things up!
07-08-2012 05:14 AM
or you split the program in two parts.
One is controlling the hardware (meaning both ports with their respective subaddresses on on rs485 port)
And two panels each having a user interface that shows a flow controller.
So it is one LabVIEW program that stops if both controllers stop.
07-08-2012 02:46 PM
I am not quite understand what you mean , Sorry ..
You mean we split one port to 2 to communicate with two labview program? so two port can interface with one Brooks 254 to control MFC in my two test stations?
07-09-2012 04:27 AM
I understood that you have one port connected to both systems and that you can communicate with both systems but not at the same time.
my conclusion is that by changing the address you can talk to both systems, without changing the hardware connection.
If that is true you can write a LabVIEW program that has two windows or one window with both instruments visible and communicate with both systems but not (exactly) at the same time.
Both windows use the same Labview subvi that handles the communication.
Please report if my conclusion is right. Than we can try to work out a way to slove your problem.