4/11/2017 8:25 AM | |
Posts: 7 Rating: (0) |
Hello, I am looking for help with PID set up ( FB41). OP27 to work with S7 300. In the attached you will kindly find a pdf with my code- sorry its handwritten but I am using the laptop which by the company's policy can not be connected to the net. Its first PID I am trying to set up and I don't understand whats happening. Operation: Its a closed loop pressure control. Both signals are 4...20mA-feedback from transmitter and output to proportional valve. Set Point from OP 27, then press start and PID kicks in to control. I have blocks FC 105 and FC 106 to scale analogue values-analogue input works well but I am not sure if analogue out is ok. I am not sure which FB 41 ports I should use as my signals entries. Also I don't know how to create a SP on OP 27 and make it talk to FB 41. At this stage system just fluctuates up and down. Any Help much appreaciated. Kind Regards, Robert ------------------------------------------------------------------------------------------ AttachmentProject Code pdf.pdf (331 Downloads) |
Last edited by: Randrukie at: 4/11/2017 8:30:06 AMLast edited by: Min_Moderator at: 4/11/2017 4:14:05 PMNew subject after splitting |
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4/21/2017 9:06 PM | |
Posts: 7 Rating: (0) |
Hello, The code now looks like in the attached. Still no joy. How would you explain fluctuations at FC 105 out say 00000.13366 to 2.445673800 at 4mA ( it also fluctuates when there is input all across the range). Thanks a lot and Kind Regards, Robert Attachmentcode 21 Apr 17.pdf (293 Downloads) |
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