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rikita
April 12th, 2015, 03:19 PM
hi , I'm trying to implement PID in step 7 using FB41.the FB41 is implemented in OB35. I know how to set parameters of PID also I know the inputs type, outputs type . the problem I get always max value at the output of the FB41 I dn't know why !
knowing that I set Kp=2 , Ti= 2s , Td= 500ms
taking SP = 2 and PV=1 I get at the output max value (LMN_PER=27648) where is the problem :(

JRW
April 12th, 2015, 03:57 PM
Show a screenshot of your call

rikita
April 12th, 2015, 04:00 PM
the FB41 is in OB35 , thnx for ur help
36325
36326

JRW
April 12th, 2015, 04:11 PM
Are you using PV real or PV Per?
Are you sure this is set correctly ?
PV PER ON

rikita
April 12th, 2015, 04:20 PM
Are you using PV real or PV Per?
Are you sure this is set correctly ?
PV PER ON
yes using PV_IN or PV_PER I get always the max value 36327

JRW
April 12th, 2015, 04:26 PM
With PV per off and a 50.0 SP
And a 45.0 to 55.0 PV - does your LMN still stay at 27648?

rikita
April 12th, 2015, 04:30 PM
at 45 I get 27648
at 55 I get 0
with SP = 50

JRW
April 12th, 2015, 04:34 PM
Ob35 at 100ms?

rikita
April 12th, 2015, 04:36 PM
yes it is at 100 ms :( I can't see where is the problm

JRW
April 12th, 2015, 04:45 PM
Im putting together some screen shots
Wait a minute

rikita
April 12th, 2015, 04:46 PM
ok thank you very much for your help

JRW
April 12th, 2015, 04:52 PM
Heres a simple set up with the PID at defaults except for the inputs as shown

rikita
April 12th, 2015, 04:55 PM
ok I'll try it now thanx a lot for your help :) can u reupload in good quality lol I can't see all parametres sorry

JRW
April 12th, 2015, 04:58 PM
another

rikita
April 12th, 2015, 05:01 PM
how do you use PID control (the other window)?

JRW
April 12th, 2015, 05:40 PM
Go here
Then open your project> open the instance DB for your PID in the ONLINE button

JRW
April 12th, 2015, 05:45 PM
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