In Function Block Editor, it is possible to define units for function blocks, and these units can only be set to basic units. There is no way to add a metric prefix to the unit. For example W or Wh can be used, but it is not possible to define kW, MW or kWh, MWh.
EcoStruxure Building Operation
Building Operation Workstation version 1.8 or earlier
Metric prefixes are not implemented for function blocks in Building Operation version 1.8 or earlier.
Upgrade EcoStruxure Building Operation to version 1.9 or later. When editing a function block In Function Block Editor click Select unit and choose unit and Prefix.