REX C100 auto tune set up

[@Mach1Mike407]

Great video - just got one and this answers my questions ! For reference, PID= Proportional, Integral, Derivative. When you tune it you want the amount of power applied to be Proportional to the difference between Setpoint and Actual/ Proces values (the further away the more power, the closer the less power. You want the amount of power to be Integrated across the passing of time, so that the longer there is a gap between Setpoint Value and the Process value the more power it applies and then finally the Derivative looks at the rate of change of the Process / Actual temp looking forward in time, if it sees that that the speed that it is heating up is getting to fast, it will reduce power. In your video, when the Process Value/ Actual temp hit 60.0 degrees, it shut off the power to the heater and then it watches how far the temp "coasts" - think of it like momentum - as the temp will continue to rise for a bit. The controller is "learning" how big this overshoot will be and then it will take that into consideration the next time it is warming up so that it shuts off the power at say 57 degrees and it will coast nicely up to 60.0 and stop. Bit of word-salad there but hopefully that helps explain it to others who happen by your video

[@pauliwie8788]

Thank you for the video! Is there any way to figure out the PID Parameters after the autotuning ?

[@PA30000]

Thanks for showing your work! How have the rex c100 hold up over time? If they failed, how long did they last? Do they need ventilation? Cheers!

[@HuntsmanBrewing]

No problems. I am still using them today and haven't had any issues. Never had to run another auto tune. Ventilation on the actual unit isn't necessary, however the SSD requires a heat sink which should be ventilated. I hope this helps

[@PA30000]

@@HuntsmanBrewing 5 years! That's reassuring. Too cheap to believe compaired to the others. Might aswell give it a punt :) Thanks!

[@christianmackintosh8084]

Hi there - I can't change the atu to 1. Nothing happens when I press the button. What has to be done prior to activating the atu?

[@HuntsmanBrewing]

Hi, My instructions in the video are not 100% accurate. It should go - hold down set until it brings up AL1. scroll through by pushing set again until atu appears. Push the up arrow until you see 1 and then set again and the auto tune should start flashing and therefore auto tuning in progress. Let me know if that doesn't work. Cheers Tim

[@ExemplaryLigas]

Rkc rex c100 is LCY 0001 and 1000

[@BrewmackerHomeBrew]

Thanks for the video, that helps a lot. Now to figure out P, I & D :) Cheers

[@HuntsmanBrewing]

Brewmacker ! it should configure it with the auto tune. Just make sure you let it run it's course and don't interrupt it.

[@ExemplaryLigas]

how much time it tooks? regards

[@frankyvee1]

Auto tune figures that out for you automatically. It takes about two cycles while it learns and records the differences then after the Auto Tune phase you will see it maintain temps within + or - a degree.

[@pinoykidboxer]

What is the autotune for? I my unit, it stops blinking after it hits the desired temperature...so what does auto tune do?

[@frankyvee1]

Autotune is just a short period of learning and recording the heating and cooling behavior. Once the autotune light turns off it is done learning and now is running with what it learned.

[@s3rkanAGA]

Thank you man

[@muralithalluri4239]

G’day mate, any chance you’re contactable via email? Having a bit of trouble with my PID. Works great but when heating too fast it short circuits, keen to know how to slow down how fast it heats up.

[@magarpalgir]

How does tuning end?

[@HuntsmanBrewing]

When it's in normal operation. Auto tune light is no longer on. It can take hours depending on your application

[@magarpalgir]

@@HuntsmanBrewing Thank you very much.