thank you for all the helps

[nw]

i also have another question,

when you master of lv said something about" I am pretty sure that's intentional. PID needs current and previous values to decide how to regulate (not that I am an expert here). Also the loop only runs once per call" how do i correct this problem, pls share your good knowledges. now finally that i got the icon, i can move on to the next level, building a project.

well, i probably needed you masters of lv help. i wanted to build a project of temperature control with labview using thermistor as a sensor for temperature, some relays and a cpu fan,,,,, how do i make these stuffs into a machine control by LV,   some helps pls,, do i need anything else?

thanks to all the MASTERS OF LV

nw

[reggier]

Hey there,

You might try checking out the examples and tutorials at ni.com.  You might find what you are looking for there.  Here is an example I found by searching "PID Temperature" and going to the example code.  It's title is Ready-to-Run Temperature Controller.

Is this along the lines of what you are looking for?

reggier

[Ray.R]

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@NW wrote:

i also have another question,

when you master of lv said something about" I am pretty sure that's intentional. PID needs current and previous values to decide how to regulate (not that I am an expert here). Also the loop only runs once per call" how do i correct this problem,

---

When using a loop with an un-initialized shift register, it is referred to a "Functional Global".  The purpose is that the first time you call the function (or VI), it sets the un-initialized shift register to the default value for the data type wired to it.  Example, numeric = 0, Boolean = FALSE, etc..

For any subsequent calls to the same function / VI, the value at the input shift register is the one which was written to the shift register during the last call.  WHich means it remembers the previous value.  The only way to reset it is to remove the VI from memory (usually closing LV), unless there is a state which initializes the shift register or resets it. 

You would have to define "correcting the problem" because the implemention was likely done this way on purpose.  Describe what you want to do with this function in more details.  Also, do a search on Functional Global, I'm sure there are some explanations and examples available..

RayR

[Ray.R]

Here's a couple of links to Functional Global (descriptions, etc):

http://forums.ni.com/ni/board/message?board.id=BreakPoint&message.id=2736

http://forums.ni.com/ni/board/message?board.id=170&message.id=71178