A Fixed Range target is a flat-line range that can be displayed on a chart to compare the operating conditions against a threshold of acceptable values. It is graphed as a band across the variable chart and highlights values based on where they are relative to this band.
To create this target, select the Fixed Range target type and select the "Show on graph" option. Three key parameters must be provided for this target:
- Resolution: determines how the band adjusts when viewing the variable in different frequencies
- In general, select the resolution of the variable itself so that the values of the fixed range adjust appropriately when viewing the variable in lower resolutions.
- Lower Limit: sets the value of the lower threshold of the band
- Upper Limit: sets the value of the upper threshold of the band
The resolution setting can be used to change the frequency of the highlight. Setting the resolution higher than the frequency of the variable will result in an error and a lower resolution will result in the target not appearing when viewing the variable chart in higher frequencies. Generally, a target resolution should match the variable's resolution.
Example
Resolutions can be explored through changed settings for a sample virtual variable with an hourly frequency. The settings for the Fixed Range target are seen below with the resolution set to hourly to match the frequency of the variable.
The below graph is in hourly resolution and the target appears normally.
The target functions normally for graphs viewing the variable in a lower resolution as well. The below graph is in daily resolution.
When the target is changed to daily resolution, the target will appear differently on charts.
When viewing the variable chart with a daily resolution, the result is the same as the scenario above.
However, when viewing the variable at hourly resolution, the target does not appear on the graph below.
The target will not appear on the variable graph if the resolution is lower than that of the variable graph being displayed. If the target resolution is set to lower than the frequency of the variable, an error message will occur, and the target settings will not be saved.