Create an engineering units dictionary

Create an engineering units dictionary to define custom engineering units. Use custom engineering units in analog variables and in the measurement systems map.

For example, you can express the number of pieces produced in 1 hour in beats per minute using custom units of measure.

  1. In Project view, right-click the Model folder and select New > All > Engineering unit > Engineering unit dictionary.
    Tip: You can create the Engineering unit dictionary in folders other than Model.
  2. Double-click EngineeringUnitDictionary#.
  3. To add a custom engineering unit row, select Add.
  4. To edit a custom engineering unit row, edit the row cells.
    Tip: The unit conversion uses the linear expression y = mx + q, where X is the input value, M is the slope, and Q is the intercept that calculates the Y output result.
    • Physical dimension. The reference quantity for the non-standard unit of measure.
    • Reference unit. A standard unit that you base the custom unit on. For example, hertz [Hz]. Blank if Physical dimension is set to None.
    • Unit id. A unique identifier of the custom unit. For example, 1.
    • Display name. The name of the custom unit. For example, bpm.
    • Description. The description of the custom unit. For example, Beats per minute.
    • Slope. The conversion coefficient to convert the standard unit value to the custom unit value.
    • Intercept. The value to add to the referenced unit of measure.
    • Result. Automatically generated comparison between the reference unit and the custom unit. Blank if Physical dimension is set to None.
  5. (optional) To delete a custom engineering unit, select a cell in the engineering unit row and select Delete.
Table 1. Example: Engineering units dictionary with a custom unit (bpm)
Physical dimension Reference unit Unit id Display name Description Slope Intercept Result
Frequency hertz [Hz] 1 bpm Beats per minute 60 0 1 Hz = 60 bpm
Table 2. Example: Engineering units dictionary with a custom unit (Chicken/m2)
Physical dimension Reference unit Unit id Display name Description Slope Intercept Result
None 2 Chicken/m2 (Chicken/m2) Chicken per square meter 0.0929 0