I know this is a lesson in proportional control but I also realized something about the ladder logic scan for the simulated level. When SimulatedLevel is at 8, CountDown is still false, so it adds one to take SimulatedLevel to 9 and then passes a true to the CountDown OTL. It then proceeds to execute the branch because we've written a one to the CountDown bit. We then subtract one from SimulatedLevel to go back to 8. The resulting graph demonstrates the result; it tops out at 8 and never gets to 9. I'm sure this is obvious to most, but was an ah-hah moment to a novice like me. Thanks for the video.
Hi Tim, I am having difficulty to control PH value using PH meter, ON/OFF acid and base valve. When I searched on the internet, it mentions Time proportional control and I am not sure how to deal with this formula. Is it the same with normal proportional control?
How will these concepts apply to loop controllers? Can I follow the same concept when programming PID on the loop controller? At our water treatment plant we use loop controllers instead of Plc.
Actually Proporcional IS multiplied by the Error. The Speed equation only writes It diferently considering the way a digital CPU deals with it. But If you deduct the equations CV = CV n-1 + Kp* DeltaE is the same thing as CV = Kp*E
Tim, thank you for your repply. I have been through that equation and it's driving me nuts. I still can't understand how to calculate the exits. Because matemathically the CV e-1 should cancel the DeltaE term. If we put numbers for instante: We have a moment t1 with error 2 and a moment t2 with error 3. And Kp of 2. At t=2 with the positional form we would have CV = E.Kp = 3x2 = 6 With the velocity form we would have CV = CVn-1 + Kp.Delta E = 4 + 2x(3-2) = 4 + 2 = 6 That's why I think It should be same. It only should be different with 2 blocks feeding CV n-1 in each other I feel there's a glich in there but cant find it. Thank you for your vídeos
@@MarceloNMF That is why this exercise is important. Plug this program into your Controllogix or Compactlogix PLC and you will see that is not how it works. Here is another resource that may help, I reference it in the other video. controls.tw/pidalgorithms
@@TimWilborne Thank you for all your help. So here is my last question: Is there a way to use a positional form PID in ControlLogix? I currently use Logix Designer, exactly like this one in your videos. Merry Christmas and thank you again
@@MarceloNMF You aren't going to be able to use Logix Designer to learn about Studio 5000's PIDE instruction. It uses the positional equation which is why you are getting confused. Merry Christmas to you!
Hi! Your channel is awesome! It covers a lot of industrial grade electrical components(like PLC). It helps me to learn them. Thanks Tim!
Glad you like them John!
I know this is a lesson in proportional control but I also realized something about the ladder logic scan for the simulated level. When SimulatedLevel is at 8, CountDown is still false, so it adds one to take SimulatedLevel to 9 and then passes a true to the CountDown OTL. It then proceeds to execute the branch because we've written a one to the CountDown bit. We then subtract one from SimulatedLevel to go back to 8. The resulting graph demonstrates the result; it tops out at 8 and never gets to 9. I'm sure this is obvious to most, but was an ah-hah moment to a novice like me. Thanks for the video.
This would actually make a good program scan video, I'll put it on the list, thanks for watching Brian!
Wonderful vídeo , thanks Tim !!!
Glad you enjoyed it Augusto!
Great video Tim, congratulations!
Thanks!
Hi Tim, I am having difficulty to control PH value using PH meter, ON/OFF acid and base valve. When I searched on the internet, it mentions Time proportional control and I am not sure how to deal with this formula. Is it the same with normal proportional control?
When I think of time proportional control, I think more of pulsed wide modulation but I guess it could have another meaning.
Great video, very helpful
Glad to hear it!
How will these concepts apply to loop controllers? Can I follow the same concept when programming PID on the loop controller? At our water treatment plant we use loop controllers instead of Plc.
Hi Darnell. 98% the same. Depending on the particular PID controller, they may use a slightly different equation but the principles are the same.
Really good series. When can we expect the I and D portion of these lessons?
I didn't like how they turned out and rerecorded them. I still need to edit them. I've been short on time lately though.
Do you have a video for the on/off control in 500?
Do you mean switching a discrete output ON/OFF or doing a pulsed output to a SSR?
Why does that look like CCW and not RSLogix 5000? Nice video
That is version 32...maybe 33 of Studio 5000 which replaced RsLogix around version 20
Actually Proporcional IS multiplied by the Error. The Speed equation only writes It diferently considering the way a digital CPU deals with it. But If you deduct the equations CV = CV n-1 + Kp* DeltaE is the same thing as CV = Kp*E
Nope, make sure you know which equation your PID is using. See if this helps. th-cam.com/video/FVTv6Gi9IJo/w-d-xo.html
Tim, thank you for your repply. I have been through that equation and it's driving me nuts. I still can't understand how to calculate the exits.
Because matemathically the CV e-1 should cancel the DeltaE term. If we put numbers for instante: We have a moment t1 with error 2 and a moment t2 with error 3. And Kp of 2.
At t=2 with the positional form we would have CV = E.Kp = 3x2 = 6
With the velocity form we would have CV = CVn-1 + Kp.Delta E = 4 + 2x(3-2) = 4 + 2 = 6
That's why I think It should be same. It only should be different with 2 blocks feeding CV n-1 in each other
I feel there's a glich in there but cant find it.
Thank you for your vídeos
@@MarceloNMF That is why this exercise is important. Plug this program into your Controllogix or Compactlogix PLC and you will see that is not how it works. Here is another resource that may help, I reference it in the other video.
controls.tw/pidalgorithms
@@TimWilborne Thank you for all your help. So here is my last question: Is there a way to use a positional form PID in ControlLogix? I currently use Logix Designer, exactly like this one in your videos. Merry Christmas and thank you again
@@MarceloNMF You aren't going to be able to use Logix Designer to learn about Studio 5000's PIDE instruction. It uses the positional equation which is why you are getting confused. Merry Christmas to you!
Very helpful video!!
Glad you think so!