02-22-2021 02:33 AM
Dear LabView Community,
first, I would like to say hello because I'm new to the community!
I'm desparately trying to create a temperture controller using the basic PID Controller vi that is able to keep the temperature stable over several days.
I used the controller tutorial as template (https://zone.ni.com/reference/de-XX/help/371361R-0113/lvpidmain/fault_protection/) and really tried a lot of options of the parameters but it doesn't work.
At first, everything works very fine but after approx. 1 hour the output value of the PID-vi drops to zero, accordingly the temperature drops and it takes a few seconds for the process to get stable again (please see attached screenshot). Afterwards this occurs every few minutes.
I can't see that the system ressources get insufficient with increasing time or something like this. I monitored RAM and CPU and can see no correlation. Also, there is no difference if I activate data logging or not. If you need any more information, I will try to provide them. Thank you very much!
My System is
Solved! Go to Solution.
02-22-2021 02:50 AM - edited 02-22-2021 03:10 AM
Hi Thermomanager,
@thermomanager wrote:
I'm desparately trying to create a temperture controller using the basic PID Controller vi that is able to keep the temperature stable over several days.
When you want to run a program on 24/7 then you need to create that program to be able to run 24/7!
This means:
When you learn from the example VIs coming with LabVIEW you will create your VI similar to this:
Btw. don't use BMP for images when you can use PNG (or JPG)! Using PNG the filesize is just 3% of the BMP filesize…
02-22-2021 05:55 AM
Hi GerdW,
thank you very much for your very quick and constructive reply. My knowledge is obviously too small and I was already too stuck to realize that the express-vi signal splitter is the problem. Actually, my first approach was all together in one while loop, but because it didn't work out I read about 10 times faster controlling than reading and parallel processing a.s.o. and then dangerous half-knowledge made everything worse. So thank you for the reminder to think about the basics first.
Also sorry for the .BMP faux pas, I'll pay more attention next time.