Hey everyone I have a few questions to ask.
For my application, I wish to make a labVIEW program which will communicate to a PID controller (bought from a 3rd party company) a set point temperature profile.
I've made calls to various PID controller companies and they have pretty much told me to contact NI about which PID controllers can be programmable using labVIEW.
One such suggestion was the multiloop P6100 from West Instruments. Could anyone else advice me which other PID controllers can be programmable using labVIEW for my application? This would be greatly appreciated.
I understand also that labVIEW can use the PID toolkit to program a PID controller, however I'm leaving my options open and just wondering where I could find perhaps a list or some 3rd party controllers that can connect to the computer and labVIEW.
I'm new to labVIEW 😄 but it seems like a very interesting program to use.
Also I wish to ask what the difference between a GPIB and RS232 are? and whats IEEE 488.2?
Finally if I could describe my setup and ask you to correct me if any of these connection interface are wrong and advice me what is correct.
I have a computer which connects to a PID controller via a RS232 or 485 port so that the labVIEW VI can program into the PID controller the set point T-profile. The PID controller will also have input from a regular plug for power 240V, and a thermocouple input. The PID controller will regulate the power supply. We have an old set up in the lab and the connection between the power supply and controller is just a channel from the PID controller to a 15 pin connection at the front of the power supply (Heinzinger PTN125-40), but now we have a new power supply with an RS232 and GPIB and a 25 pin analogue controller port. I'm guessing I use the RS232 or GPIB to communicate from the PID controller to the power supply?
Finally the power supply will connect to a heater and a themocouple from the heater will give feedback to the PID controller.
Thank you for taking your time to read and reply!
I am not sure I understood your setup, entirely. Anyway, there are multiple ways to approach the experiment:
- You could read back the signals from your external PID controller and use some logic in LabVIEW in order to switch the power supply accordingly (using a VISA, i.e. RS-232 or GPIB connection from the PC to the power supply).
- You could also just read the temperature, do the entire PID algorithm in LabVIEW and output the required data to the power supply. This approach might be less efficient. Software based PID might be slower than a dedicated PID controller. However, it allows a lot of flexibilty.
- Whether or not you will be able to directly interface your power supply from your PID controller, I cannot say. It depends on how easily you can program the controller's output and to what extent you can communicate with its serial port. You would have to refer to the devices' manuals for that.
Let me know if you have further questions.
Thanks for your answer, its very helpful.
I've thought of those methods and just wondering which one to pick because i have no experience before using labVIEW.
In the laboritory at work we have a set up: Its just a PID controller connected to a Power supply though a communication channel at the back of the PID controller and a 15 pin connection at the front of the power supply (heinzinger PTN125-40), i'm not sure what this connection exactly is sorry. But it does communicate that way.
My idea was to just make using LabVIEW a program to write a set point tempereature profile and input that into a PID controller and then the PID controller much like the current lab set up will just connect to the power supply and regulate it. In other words instead of manually pressing buttons on the PId controller, the labVIEW program will set the profile up. Seems kinda pointless but thats my task.
I have thought of your second option: "- You could also just read the temperature, do the entire PID algorithm in LabVIEW and output the required data to the power supply. This approach might be less efficient. Software based PID might be slower than a dedicated PID controller. However, it allows a lot of flexibilty." Are there specific examples I can look at to do this?
One other question not very related. Is it better to run the program off labVIEW, or making it an executable file and run it? the computers in the lab are not fantastic, in fact they're just borderline so running labVIEw program itself takes a lot of processing power. Does the executable file require less processing power? And which addon in labVIEW or package can make executable files?
thanks and i look forward to your reply
the application you descibed makes perfect sense. After all, a lot of people use LabVIEW for exactly that purpose: To control 3rd party instruments.
Examples and tutorials for PID control are shipped with the PID toolkit and can also be found on various websites. Of course you could program your own custom PID control algorithm just by following the PID control theory. You probably will be able to find custom PID algorithms for LabVIEW if you search the web.
As to your performance question: Typically, you would expect equal performance of your program in both the runtime environment and the development system. You might be able to observe slightly improved performance as an executable (depending on your program's functionality, dynamic calls, etc).