Need everyones help on a PID problem

[Wildcat]

Thanks pensrock.  At the moment I am trying to figure out how to do the auto tune.

Mike - Pat did send me some kind of literature on this thing.  I will get it out an look again.  When I looked at it when it arrived it was all Greek to me.

[Mr Walleye]

WildCat

On one of the pages it does show a chart of some sort on what you will see as you step through the menu. Have a look at it and you should find where you will find the At function. I just had a look at the Auber site but they don't have the manual in .pdf format. A year or 2 ago I did get one from them (that's the one I sent Tiny) but for some reason I don't have it here at the office.

Mike

[Tiny Tim]

I'm back.  All I had to do was press and hold the set button, then the display changed.  To progress through the menu, I did a "press and release" of the "Set" button..first up was "ALM 1", then "ALM 2", then "Hy 1", then "Hy 2", then "Hy", and finally "At" (the "T" does look a bit funny, kinda like an inverted "F").

If this don't work, call me on my cell tonight after 5:45 Central time, PMing my cell # to you as soon as this posts.

[Mr Walleye]

I think Tiny has it.

The only thing I would add is not to start the autotune until the temp (with load) has reached within 10 degrees of your target temp.

Mike

[Wildcat]

Thanks TT and Mike.  After reading Mike's post, I looked in the manual and saw what the "At" looked like.  I then followed TT's instructions and it is now auto tuning (I think).  The lower (green) numbers are flashing between my set temp and the "At" symbol.  I only hope this is all it needs.  I still have a little concern about displaying multiple temp readings within seconds that vary by about 10 degrees.  Hopefully this auto tune will resolve the problem.

[Mr Walleye]

Yup, I would let it run through the autotune, then see how it works.

Keep us posted.

Mike

[Tiny Tim]

Looks like ya got it under control.  Give me a call if you need something later.

[MRH]

Wildcat,

Here is the directions right from the manual hope they help:

6.2.3  Fuzzy Logic enhanced PID control and autotuning

For the first time user, it is a good idea to use the auto tuning feature to let the controller automatically determine the PID constants. To start auto tuning, you need to set At=2 (see 6.5.3 for details).  During auto tuning, the instrument executes on-off control.  After 2-3 times on-off action, the microprocessor in the instrument will anelyze the period, amplitude, waveform of the oscillation generated by the on-off control, and calculate the optimal control parameter value.  The instrument begins to perform accurate artificial intelligence control after auto-tuning is finished.  If you want to exit from auto-tuning mode, press and hold the (A/M) key for about 2 seconds until the blinking of "At" symbol is stopped in the lower display window.  Generally, it will meet your need to perform auto tuning one time only.  After the auto tuning is finished, the instrument will set parameter "At" to 3, which will disable triggering of auto-tuning with the (A/M) key.  This will prevent an accidental repeat of the auto-tuning process.

6.5.3 Control mode parameter "At"

At=0 ON OFF control, suitable for the applications which don't need high precision
AT=1 Get  the controller ready to start the Auto tunning by pressing A/M key.
At=2  Start auto tuning. The function is the same as starting auto tuning from front panel.
At=3 This configuration is automatically set after auto tuning is done.  Auto tuning from the fron panel is inhibited to prevent accidental re-starting of the auto tuning process. to start auto tuning again, set At=1 or At=2.


Thanks to my wife for typing, you would be done before I got it typed!!
Mark


Looks like it took me too long.... Oh well here it is anyway ;D

[Wildcat]

Thanks MRH.

OK guys - here are the results.  I ran auto tune 3 times.  First set P=12 I=126 D=4.  Forgot to write down second run results.  Third run P=196 I=9500 D=107.

PID temp probe reading 214 to 222 (bouncing around these numbers within seconds) and within a few minutes 218 to 226.  Many other sets every few minutes.  I have the PID set for 220.

Chicken (skinless) currently at 130 and Maverick reading a box temp of 198.  Door gauge on BS reading 198 to 200.

What next?

[Mr Walleye]

WildCat

Where abouts in the cabinet do you have the TC mounted?

Mike

[pensrock]

Mike, you may be onto something there. Some T/C's cannot touch ground or it will cause interferance. I would move the T/C or rest it on something that is not metal. Or even just hold it in your hand to see if it settles down.

[Mr Walleye]

WildCat

When you say bouncing between 214 & 222 do you mean you would see 214, then in a few seconds it changes to 222?

Or... do you see 222 and it slowly climbs to 222?

Mike

[pensrock]

It also seems odd that he was able to complete three autotunes in such a short period of time.

[Wildcat]

When I went to check the PID was reading 227 to 236 and the Maverick indicated 208.  It bounces around within seconds.  Did another auto tune and the numbers are: P=20 I=593 D=7.  The sets of numbers creep up and down but there is always a range of about 9 degrees that bounce around.

Today I have the Temp probe mounted with a metal holder that the Maverick set had.  The other day I was having the same problem with numbers bouncing and I had it set through a small chuck of ham to hold it off of metal.

[Wildcat]

Forgot to mention - by TC I assume you mean the temp probe from the PID that goes into the cabinet.  I have it on the third shelf below the chicken where the juices cannot drip on it.  I have the Maverick probe in the same general area.