PID Controller output goes to zero after download of application.
Hi.
I have problem with a PID-Controller, the output of the controller goes to zero after a new application has been downloaded into the controller (Controller in Auto). The controller then starts regulating as before but it starts from zero.
The control module being used is PidCC from the ControlStandardLib 1.6-8.
The system is a 800xA 6.0.3 with PM866 controllers.
There is about 100 instances of this type in the project but there is only problems with one specific.
I have tried to disconnect all ingoing pins and replaced it with constants (PV,SP,Track) to exclude any "first scan" issues from other blocks going in to the controller without any differences. Switching between internal or external set point doesn't make any difference.
Any suggestions?
I have problem with a PID-Controller, the output of the controller goes to zero after a new application has been downloaded into the controller (Controller in Auto). The controller then starts regulating as before but it starts from zero.
The control module being used is PidCC from the ControlStandardLib 1.6-8.
The system is a 800xA 6.0.3 with PM866 controllers.
There is about 100 instances of this type in the project but there is only problems with one specific.
I have tried to disconnect all ingoing pins and replaced it with constants (PV,SP,Track) to exclude any "first scan" issues from other blocks going in to the controller without any differences. Switching between internal or external set point doesn't make any difference.
Any suggestions?
Asked 5 months ago
Answers
0
Hello,
As u said the prob is specific in one pid then please look into how Interaction parameters behaving.
Guess
Look at the variable might be without "retain"attribute and using for to trip control valve on on de-energised state so on warm download of controller variable with no attribute will set its value as "0" and in turn causing output 0/any predefined value
As u said the prob is specific in one pid then please look into how Interaction parameters behaving.
Guess
Look at the variable might be without "retain"attribute and using for to trip control valve on on de-energised state so on warm download of controller variable with no attribute will set its value as "0" and in turn causing output 0/any predefined value
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