11/7/2011 10:35 PM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating:
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Dear JanLan, I believe online manual provided in STEP 7 on FB41 will answer to all your questions here.Diagrams and formulas will help you to understand the whole algorithm and relation between each section easily .I upload the "pdf" version of the online help for quick reference .
As you follow the diagrams and formula in the attachment, output of LMN limiter block is determined by high and low limit there (e.g 0 to 100) and by LMN_NORM block , you can create linear transform of the input.For example, in some case you need to change (0 to 100) of normal PID algorithm to 100 to 0(LMN = (output of LMNLIMIT) * LMN_FAC + LMN_OFF).
Check some examples here:Standard PID Package - FB41 Samples ( ![]()
For this issue ,"Bumpless PID" would be a great help on bumpless implementation of algorithm.Also check here to see here "Why is manual to automatic changeover in FB58 bumpless?".
For more academics details on PID controller refer to THIS which is great reference to understand the behavior of algorithm. Chapter 3 (PID control) of this book is a great help to understand the issue and eventually design your own controller! Best regards, Hamid Hosseini AttachmentFB41.pdf (592 Downloads) |
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