7/4/2014 10:03 PM | |
Posts: 5 Rating: (0) |
Dear Daniel Here you go, this is in ladder.
AttachmentOB35.pdf (430 Downloads) |
7/4/2014 10:18 PM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating: (1365)
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Hello, You code suffers from bad using of memories.MD2 as the result of LMN is written to consists of MB2,MB3,MB4,MB5. The bit pattern of MD2 that is a floating point number, for sure affects the M3.0 and M3.1.This is a big problem, your algorithm is in COM_RST mode and back again or even Manual to auto mode in a random pattern and this may cause damages to your actuator or piping (in case of the valve).Same problem with MD100 as used as Setpoint.
My suggestion would be:
More tips regarding FB41 in the following tag: HD PID Control Package - FB41 Samples I hope these comments help you Hamid Hosseini |
Last edited by: hdhosseini at: 7/5/2014 5:13 AM// M3.0 and M3.1 Last edited by: hdhosseini at: 7/4/2014 10:53 PM |
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7/5/2014 5:25 AM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating: (1365)
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Good Morning World, As it is explained previously by Expert friend "Daniel Chartier",Memory addresses for command or other interfaces to PID controllers should not be used anywhere in your program.You should check the byte address allocated for clock memory.You should also check each memory with "Go to Location" facility for all read and write places."Overlapping access to memory areas" reveales all mysteries.See the attachment.
For each command and task you should set a side unique addresses and resources.You can not assign a single timer for several task because it will lead to a chaos/malfunction in your program.It is a rule and you only ignore that.M3.0 and M3.1 are part of MD2 and you should not use them for other tasks. Plus all notes,I suggest reading my following clustered threads to gain a solid knowledge in STEP 7: HD_STEP7 Starting Point |
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