SelectionValuesAfterChangeWithTimeWindow

ValuesAfterChangeWithTimeWindow

Selection

The transformation SelectionValuesAfterChangeWithTimeWindow can be used e.g. to filter out measurement values during periods where the measured system is not in a (quasi) steady state due to changes happening in the system. This transformation creates a time window after each change in a configured condition variable. The length of each time window is determined by a custom expression in the configuration. Depending on the configured selection type the input values inside or outside the time windows are selected. All selected input values are then copied to the output variable. Missing output values are produced at times where there is not enough reliable or doubtful data available in the condition and/or expression variables to determine if there is a change or to determine the length of a time window. Any such missing output values are truncated from the start and end of the run period of the transformation, to avoid overwriting data from previous runs with overlapping run periods.

Can be used e.g. to filter out measurement values during periods where the measured system is not in a (quasi) steady state due to changes happening in the system. For example when a pump is switched on/off in a system of pipes, then the pressure in the pipes will fluctuate for some time until reaching an equilibrium value. If data analysis depends only on the equilibrium value, then this transformation can be used to filter out the fluctuating values just after a pump has been switched on/off in the system.