09-16-2010 07:20 PM
Hey, I am an undergrad student who is fairly new to labview and control systems and I am working on a senior project. I am wanting to use labview to simultaneously control two separate machines. Both machines would send back data to be saved to a file. They would both be connected to a NI DAQ(SC-2345). Is this reasonably attainable? Will labview and/or the DAQ have problems running two machines simultaneously? I would love any suggestions. Thanks
09-16-2010 08:58 PM
Let me see if I have your setup pictured correctly. You have 1 PC, 1 DAQ card that is connected to the SC-2345 signal conditioning carrier. Do those modules, you have two different physical machines you want to control. Am I correct?
Do you want to have one LabVIEW application controlling both machines independently? Or two different LabVIEW applications each controlling one machine?
Your one constraint is that since there is only one DAQ card, all DAQ functions have to be handled at a single point of code otherwise you'll get errors about resource conflicts. In other words, you can't have two separate programs eaching trying to work with a single DAQ card.
So you can have a single point of interface with the DAQ card and use architectures such as Producer/Consumer to pass messages back and forth from your other parts of the code. The other parts of the code can be two independent loops that handle the machine control logic for each machine.
The easiest to program would be to have on application that handles both machines. It would have 3 loops, two loops where each loop is for logic for each machine, and one loop that handles the DAQ communication.
If you want to have two separate applications, you can do that as well where each application handles the machine logic and a third background application handles the DAQ communication. It just needs a little bit more sophisticated communication scheme to pass data between the different applications.
09-18-2010 04:48 PM
Yes, there are two physical machines. One labview program will control both machines independently.
09-19-2010 12:09 PM
And what type of control signals do you need to provide? Analog, digital? Using a PID?
Also, you have not mentioned the actual DAQ card. The SC-2345 isn't and you need to understand the difference between this signal conditioning module and an actual DAQ device.