WindowAlarm('Expression','Limit1','DeadBand1','Limit2','DeadBand2','Time',' Reset=0')
Arguments
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'Expression' |
Measured value |
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'Limit1' |
Upper limit value, from which the function returns TRUE |
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'DeadBand1' |
Specification of the dead zone below the upper limit value ('Limit1'), within which the function does not reset to FALSE |
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'Limit2' |
Lower limit value, from which the function returns TRUE |
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'DeadBand2' |
Specification of the dead zone above the lower limit value ('Limit2'), within which the function does not reset to FALSE |
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'Time' |
Specification of the time, for which the measured value must be greater than the upper limit or smaller than the lower limit until the function returns TRUE |
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'Reset' |
Optional parameter (default = 0) to stop and restart the calculation |
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'Reset'=0 |
Perform calculation |
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'Reset'=1 |
Stop calculation, reset and set result to 0 |
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'Reset'=2 |
Stop calculation and keep result |
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Description
This function monitors the measured value ('Expression') and sets the result to TRUE if the measured value is longer than the specified time ('Time') outside the range between the upper limit value ('Limit1') and the lower limit value ('Limit2'). The result of the function becomes FALSE again if the measured value falls below the upper limit by the value specified under 'DeadBand1', or exceeds the lower limit by the value specified under 'DeadBand2'.
Example
The function is to be triggered if the measured value is outside the value range between 8 and 12 for longer than 0.4 s. The upper dead zone should be 0.5, the lower dead zone 0.3.
Solution
In the figure below the blue curve shows the measured value and the red bar shows the triggers the WindowAlarm function. The green areas show the dead zones of the respective limits.
