PID control in a windows CE Labview application

[manost]

Hi there,

I want to build an application that will control the temperature in some ovens, using PID control. The application will be running in a controller (or a touch panel computer) with windows CE OS. I have Labview 8.6, PID control toolkit 8.6 and Touch panel module 8.6. The problem is that the PID vi's don't seem to work in touch panel module. 

Is there any way to implement PID control in a windows CE Labview application?  

Thanks in advance.

[Hillman]

Hi Manolis,

Good afternoon and I hope your well today. I believe the LabVIEW mobile module (formly PDA) comes with a PID.VI. The "PID gains" and "output range" inputs for the PID.VI are clusters. Since the PDA module does not allow cluster controls, numeric controls will need to be used and then clusters created via the "bundle" function on the block diagram.

NOTE: "PID Autotuning" is not available in the PDA module due to the use of formula nodes which are not supported by the PDA module.

Where you aware of this, and have you tried this?

[Coq_Rouge]

Hi

I have tested the touch panel module, and dropped it because the serial communication did not work with a CE 6.0 build image(OS), and lack of support from NI (sad to say). So I guess touch panel module not used with a NI hardware is a seldom combination. Anyway since each CE OS is a custom build OS. It could be that you miss some of the modules that the labview EXE is calling. I also think the touch panel module now support clusters. If you build you own CE image I can give you some pointers 

[manost]

Hi again.

Thank you both for your responses.

I haven't tried Labview Mobile module because I don't have it. Is it certain that it comes with PID vi's? I don't want to buy it unless I am sure and in National's relevant web page (http://sine.ni.com/nips/cds/view/p/lang/en/nid/12222) doesn't say a thing about PID.

From your answers I understood that I should probably forget about using a Touch panel computer. Maybe I should try the windows CE controler with a simple touch screen. And that is only if the Labview mobile module supports PID, else I should forget about CE in general.  

[Coq_Rouge]

Hi

First of all the touch panel module is the correct module to use. Even if did not do any good for me it might work for you. Just test it and tell us more about your problem. How does it not work?

[manost]

My problem is that the Touch panel module doesn't have any PID control vi's, in order to use in my application.   

[Coq_Rouge]

Not working it not good enough;). Why is it not working. For example can you start the exe file after installing it on the host. Do you get some errors. I took a look at the PID regulator is have no fancy functions using DLLs. It is pure Labview

[Hillman]

Hi Manolis,

I hope your well today. I just wanted to check-in again to see if you still required any further support with your issue?

My concern with performing PID on a touchpanel would be the loop rate you could acheive, and using a usb device. Generally, you wouldn't perform tight PID on a windows PC for example. You would consider a cRIO or PXI system. However, this obviously depends on your applicaiton and needs. 

I think in conclusion, it should be possible to perform PID on a touchpanel (its just maths) but how effective it will be in your system is a different question. 

Please let us know, 

[Coq_Rouge · Accepted solution]

I think with a timed loop you can run reasonable good timing down to 1 mSecond. I think 1 mSecond is the lower limit for non realtime systems like Windows/windows CE. And if you have the PID toolkit this will supply you with the functions you need. You do not need an extra CE PID toolkit. This because  the touch panel module run under your standard Labview environment. But I do not know if all the functions in the PID tool like fuzzy logic are compatible with CE. Have you also considered Windows Embedded as OS for your module. With windows Embedded you can run standard Labview built exe files

Both Windows Embedded, and XP Embedded can be trailed

http://www.microsoft.com/windowsembedded/en-us/products/westandard/default.mspx

[manost]

Dear friends,

I am sorry for my late response but I was away all this time and I wasn't working on the specific project. It seems that you are both right and that PID control vis can work with the touch panel module. At least some of them. I don't know If my loop timing will be fast enough to achieve a decent control but I have a good chance of doing it since my application will run on a WinCE embedded controller with built in I/O boards.

I have another question now concerning Labview communication with SQL server compact 3.5, but I will post another thread.

Thank you both for your support.