Use derivative to control signal

[Emm]

I'm trying to control a heating element by the difference between the user-set target temperature and the (absolute) extreme (user-set) temperature.  I've considered testing for cases using first and second derivatives.  From some reading, I've come across the idea of PID, but I can't view any working, accurate samples to even see if this is where I want to go.  I'm in the planning stage, so I've only minimal code.  My first step is "Intake Temperature Signal" (currently simulated by a gentle sin wave, just for a sim).  Second, "Analyze Temp Signal"; third, "Analyze Temp Derivative(s)"; fourth, "Combine Signals" (somehow); and last, "Re-Analyze (or confirm) Temp Signal".

Thanks! 

[Emm]

Oh, for the question -- any directions to where I can see good examples of PIDs, or confirmations that this is the direction that will take me where I want to go?

Thanks! 

[Emm · Accepted solution]

I've since realized I inadvertantly posted this in the wrong area.  I've re-posted in the correct area, but cannot see how to delete this erroneous post.

[The_Chancenator]

Hi Emm,

If you could please post a link to the new thread here, then other users who stumble upon this post can be redirected to the new one.  

Thanks!

[Emm]

Good idea, thank you!

http://forums.ni.com/ni/board/message?board.id=170&message.id=458008#M458008