How to check PID is working or not

Discussion in 'The Projects Forum' started by ep.hobbyiest, Aug 31, 2015.

  1. ep.hobbyiest

    Thread Starter Member

    Aug 26, 2014
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    Hi

    i am doing pid temperature controller. but now i have 8051 controller only. No extra h/w to check the pid is running or not.
    So, is there any solution so i can check weather it is running or not.
     
  2. crutschow

    Expert

    Mar 14, 2008
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    Watch the temperature.
     
  3. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Record the output of a sensor with your micro or just use a thermometer as suggested by Carl.
     
  4. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Could you show the circuit, please?
     
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    1) You make a graph of actual temp vs target temperature.
    2) Make trials with just the P control turned on, I and D disabled.

    3) If you do not overshoot your target temp in step 2, increase the P parameter (gain) and Repeat
    NOTE: if you do not get overshoot of temperature above your target, you do not need I and D parameter

    4) if you do get overshoot, then repeat the heating cycle and turn up the "I"parameter you reduce the overshoot. If that accuracy is good enough tracking of target temp, then you don't need the D parameter. You can keep turning up the I parameter until you get oscillation (undershoot after the overshoot).

    5) Once you have slight oscillation, turn up the D parameter until your oscillation stops.

    That is the general idea. Other people may have other strategies.
     
  6. ep.hobbyiest

    Thread Starter Member

    Aug 26, 2014
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  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    A PID in this case is not a circuit, it is the logic and programming inside the chip. So, you need to show us the software (firmware) that you have loaded into the chip.
     
  8. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    I expected an analog controller.
     
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