Use this command to add a datum point to the drawing for datum dimensions.
Once selected the Ribbon changes to show the current dimension properties and the command prompt reads:
Give datum point:
Simply place the datum point symbol using any of the snaps and input options.
Having placed the datum point on the drawing, you can then add horizontal and vertical datum dimensions.
If the datum point is then moved and repositioned on the drawing, the datum dimensions will then be updated automatically during the next Refresh command so that the dimension values are calculated from the new datum position. To move the datum simply click on it to select and reposition using any of the snaps and input options.
Only one Datum position is allowed per drawing. If you attempt to place a second datum the appropriate error message will be displayed.