5/30/2011 9:54 AM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating:
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Hi I followed these steps and check your codes with PLCSIM: 1-PV and LMN and Setpoint are disconnected from your logic, PV and SP in range 0 to 100 2-PSEL and I SEL are always true,They are not selected from HMI 3-LMN is fed to FB100, process simulator and the output of the function fed to PID algorithm as PV. The result is, there is no jump when you swith from manual to auto.I guess the problem occured because of one of BOLD item determined.We do not know any thing about the logic interfaceto the HMI.But I am sure the controller works fine , if there is no wrong interface to it. I will upload the program I worked with. regards Attachmentpudd.zip (561 Downloads) |
Last edited by: hdhosseini at: 5/30/2011 11:24 AM |
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5/30/2011 9:55 AM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating:
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This is the snapshots of the checked result regards AttachmentVID.zip (511 Downloads) |
Last edited by: hdhosseini at: 10/1/2018 4:16:41 PM |
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6/1/2011 12:15 PM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating:
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Hi This is why we are here, Reading problems and find solution for them.Thanks to give us the chance to undrestand another Pitfall of PID controllers. regards |
Last edited by: hdhosseini at: 6/1/2011 12:22 PM |
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6/10/2011 1:13 AM | |
Posts: 53 Rating:
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Thank you! |
This contribution was helpful to
1 thankful Users |
2/23/2012 5:07 PM | |
Joined: 9/16/2008 Last visit: 8/29/2024 Posts: 56 Rating:
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Hi, I'm facing a problem for a PID controller. Its for a Crown COntrol in 20 Hi Mill where 1 micron accuracy is required. Here I'm attaching my source code along with the IBA file. The problem is when I'm going from a higher value to a very low value there is undershooting which is not good. I try to control but its not happening. Can any one suggest me how to tune it for getting better result. Regards, AttachmentCrowndata.zip (441 Downloads) |
2/23/2012 7:48 PM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating:
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Dear bigbang, It is much better to upload snapshots of results instead of IBA file.Note, sudden change in "Setpoint" may cause the "Undershoot" you mentioned.Using "ROCLIM-Rate of change limiter" is recomended because all Steps in Setpoint are converted to ramps with a selectable increasing and decreasing rate.I introduced a rough version of a rate limiter in this thread, you can try that. Another tip, check LMN_P,LMN_I and LMN_D individually.If any irregular response, try to rectify parameter corresponds to that component. For tuning option, check the following: PID SELF TUNER
Best regards, Hamid Hosseini |
Last edited by: hdhosseini at: 5/7/2013 10:36 AM//typo |
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