Output value limits
In the "Output value limits" configuration window, configure the absolute limits of your output value in percent. Absolute output value limits are not violated in neither manual mode nor automatic mode. If an output value outside the limits is specified in manual mode, the effective value is limited in the CPU to the configured limits.
The output value limits must match the control logic.
The valid output value limit values depend on the Output used.
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Output |
-100.0 to 100.0% |
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Output_PER |
-100.0 to 100.0% |
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Output_PWM |
0.0 to 100.0% |
Reaction to error
| Notice | |
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Your system may be damaged. If you output "Current value while error pending " or "Substitute output value while error pending" in the event of an error, PID_Compact remains in automatic mode. This may cause a violation of the process value limits and damage your system. It is essential to configure how your controlled system reacts in the event of an error to protect your system from damage. |
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PID_Compact is preset so that the controller stays active in most cases in the event of an error. If errors occur frequently in controller mode, this default reaction has a negative effect on the control response. In this case, check the Errorbits parameter and eliminate the cause of the error.
PID_Compact generates a programmable output value in response to an error:
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Zero (inactive)
PID_Compact outputs 0.0 as output value for all errors and switches to "Inactive" mode. The controller is only reactivated by a falling edge at Reset or a rising edge at ModeActivate.
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Current value while error is pending
If the following errors occur in automatic mode, PID_Compact returns to automatic mode as soon as the errors are no longer pending.
If one or more of the following errors occur, PID_Compact stays in
automatic mode:-
0001h: The "Input" parameter is outside the process value limits.
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0800h: Sampling time error
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40000h: Invalid value at Disturbance parameter.
If one or more of the following errors occur in automatic mode, PID_Compact switches to "Substitute output value with error monitoring" mode and outputs the last valid output value:
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0002h: Invalid value at Input_PER parameter.
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0200h: Invalid value at Input parameter.
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0400h: Calculation of output value failed.
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1000h: Invalid value at Setpoint parameter.
If an error occurs in manual mode, PID_Compact continues using the manual value as the output value. If the manual value is invalid, the substitute output value is used. If the manual value and substitute output value are invalid, the output value low limit is used.
If the following error occurs during a pretuning or fine tuning, PID_Compact remains in active mode:
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0020h: Pretuning is not permitted during fine tuning.
When any other error occurs, PID_Compact cancels the tuning and switches to the mode from which tuning was started.
As soon as no errors are pending, PID_Compact returns to automatic mode.
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Substitute output value while error is pending
PID_Compact outputs the substitute output value.
If the following error occurs, PID_Compact stays in "Substitute output value with error monitoring" mode and outputs the output value low limit:
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20000h: Invalid value at SubstituteOutput tag.
For all other errors, PID_Compact reacts as described for "Current value while error is pending".
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