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| 9/5/2011 12:04 AM | |
Joined: 7/17/2010 Last visit: 2/17/2024 Posts: 184 Rating:
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Staff have to configure a PID will have to use a FB41 and FB105 Scale, I am having problems with the FB41 can not set up, I'm having problems like the block does not work do not change variables, I've read several tutorials and saw some examples but nothing comes out I will use it within a CF. Help me please, I'll send the program and a photo attached. would like to work according to the PID set point. Help please Thanks in advance AttachmentDesen_PL.zip (328 Downloads) |
| 9/5/2011 2:08 AM | |
Joined: 9/27/2006 Last visit: 11/9/2024 Posts: 12293 Rating:
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Hello Martins; I do not have access to the programming software this weekend, so I cannot open your file. However, there are standard issues that need to be takern into account for the FB41 to run, and they are well documented. Look here for example: FAQ on suggestions for FB41 parameters: http://support.automation.siemens.com/WW/view/en/18459342 If I remember correctly, 2 parameters are essential for FB41 functions to be active: 1.Make sure the Man_ON bit is set to TRUE (assign a bit addressthat isset to'1'as an input) 2. The COM_RST bit has to be set in OB100 (so it is active once before the PLC comes online), and the reset after the call of the FB41; this will allow FB41 to be enabled. FB41 sample thread: /tf/WW/en/Posts/61271#top |
| 9/5/2011 6:22 AM | |
Joined: 1/28/2009 Last visit: 10/26/2024 Posts: 6852 Rating:
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Dear Martins_Eng Just to add some points, 1- Be ensured that PVPER_ON= False because you provide the PV after scaling function. 2- Your P,I ,D(if D applicable) parameters should be selected correctly. As an example Ti=1s is to small.There are lots of methods to obtain optimum values of P,I,D parameters such as: PID Self Tuner: Example Adapted to Standard PID Control V5.1 3-Check LMN_P,LMN_I and LMN_D while controller in automatic mode fro troubleshooting 4-Be sure that the FB41 is called in a cyclic interupt OBs like OB35 5- Also check this How do you create and update multiple instances? 6-Note, if PV>SP use negative gain, this is a process related data! Best regards |
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