Explanation of formula variables
Meaning of the variables in the following formulas:
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Variable
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Meaning
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Present sample time
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System deviation (SP - PV)
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System deviation (SP2-PV2)
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System deviation value from the previous sampling step
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OFF
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Offset at the output of the P-controller
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Y
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Manipulated variable
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YI
|
I component
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YP
|
P component
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The output of the master controller is determined as follows:
Overview of the calculation of the control components
There now follows an overview of the varying calculations on control components and outputs based on the various modes:
The output signal Y of the cascade controller is:
The integral component Y1 of the sub controller for the automatic mode is determined as follows:
The I component is formed according to the trapezoid rule.
The output signal Y of the cascade controller is:
The input signal SP2 of the sub controller is:
The integral component Y1 of the sub controller for the manual mode is determined as follows:
The output signal Y of the cascade controller is:
The input signal SP2 of the sub controller is:
The integral component Y1 of the sub controller for the halt mode is determined as follows:
The output signal Y of the cascade controller is:
The input signal SP2 of the sub controller is:
The integral component Y1 of the sub controller for the fixed setpoint control mode is determined as follows:
The proportional action coefficient YP is determined as follows:
