5/31/2019 1:58 PM | |
Joined: 9/27/2006 Last visit: 9/22/2024 Posts: 12282 Rating: (2685)
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Hello Nobyz; Have a look at our friend hdhosseini's switchover suggestion and code in the following discussion, it shows a way to program bumpless transfer for PIDs, when moving from manual to auto mode or during setpoint changes. This could be useful in your own application. https://support.industry.siemens.com/tf/mu/en/posts/s7-300-pid/47135/?page=0&pageSize=10 Hope this helps, |
6/1/2019 10:30 AM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating: (1365)
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Hello,
Just want to add new thoughts to what has been suggested by Daniel, You perform the mode change by your process conditions and it can be a binary signal.When PID1 is controlling , PID1 is auto and PID2 in manual and output of PID1 is cyclically written to manual value of PID2 (LMN1-->MAN2).When you select PID2, you put PID2 in auto and PID1 in manual.Manual to auto mode is always bumpless in FB41. Other points are shared HERE. Kind regards, hdhosseini |
6/1/2019 2:33 PM | |
Joined: 12/9/2010 Last visit: 10/8/2022 Posts: 623 Rating: (77) |
Hi Nobyz80, I think for two diffrent PIDs, there is no possibility of bumpless transfer. Advice- I think, go with single PID. Connect memory DW for parameters like (P, I, D etc). Depending upon your logic, move P,I,D parameters for PID-1 & PID-2. Thus being single PID, there is no need to initialise output for every switch-over. Note-DO not modify A/M bit during switch-over. |
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