control pull down menu while VI is running

[jaswri]

i am new to LabView, i am a student.  I am working on a vacuum chamber and want to put in some extra controls for the heater.  right now i have it designed so that there is a simple pull down menu set as "contorller", has options of heat off, low, mid, high.  i want to check while my VI is running if the heat rises above a set temp, 150, and if it does i want to turn my heater off. this part i can do, i used a simple pid case.  what i can not seem to do is to change the value on the pull down menu.  i am not sure if this can even be done, since the pull down menu is a "controller" and not an "indicator". i have a indicator too on the front panel and it will display the correct value after the pid loop.  so i guess this is more for the "look" and to try and eliminate any user errors from them not knowing if the heat is on or not.   lol i am sure there are nicer ways of doing this so if anyone has a solution other than what i was thinking please let me know. i would love to get some feed back from more experienced users.  thanks for the help.

[Gak]

Can you post your code? In labview 2009?

[jaswri]

oh i am sorry i forgot to mention that i am using LabView version 8.2.  it is at least not the student verison.  lol

as for the code request i will have to do it tomorrow morning.  it is on my comp in the lab and i dont have remote access to it

[Marty_H]

Hi,

I have attached some code that might help.

Regards

Martin

[jaswri]

hi thank you for your help.  i happen to be running on an older version, i am a grad student.  we have version 8.2.0. is their any way that you can send me that code in 8.2.0. i can not open it as of right now, so that i can look at it

[Dennis_Knutson]

You should post your code. Generally, a control should be selectable at any time unless you've done something silly like place a while loop inside an event and have the front panel locked.

[jaswri]

ok here is the code with no pid controls in it yet.  i am also having trouble with reading my temp and being able to keep that value while i read another then compare the two together to see if the temp has risen.  if you could help with either of these it would be a great help.  thank you very much for your help

[Dennis_Knutson]

There is no while loop in your code so it will only run once and selecting any pull down after clicking run does not make any sense. If you are using the run continuous button, STOP doing that and place a while loop around the part of your code that you want to run.

p.s. Your block diagram is huge and I am unable to see all of it without a lot of scrolling. Make it smaller.

[Marty_H]

Here it is.