Model-Based Definition > Model-Based Definition > Geometric Dimensioning and Tolerancing Advisor > Advisor Message Help > Datum Messages > Targets Not Properly Constrained
Targets Not Properly Constrained
The datum which has been derived from datum targets has not been properly referenced in a DRF, so the locations of the datum targets are not adequately constrained. All datums derived from datum targets must be referenced by a DRF in order to establish the constraints for its targets according to the table below.
Datum Type
DRF Requirement
Comment
3-point Plane
ASM
2-point Plane
ASM
1-point Plane
ASM
2-center-point Axis
ASM or AAX
— ASM DRF required if the datum references target points (rather than circular curves)
— The angular basic dimensions for point targets are not created automatically, but are recommended
1-center-point Axis
ASM or AAX
— ASM DRF required if the datum references target points (rather than circular curves)
— The angular basic dimensions for point targets are not created automatically, but are recommended
Where,
• ASM is a fully constrained datum reference frame (e.g., 3 translation and 3 orientation DOF constrained).
• AAX is a datum reference frame that is fully constrained except for the orientation about the primary axis.
In order to address this problem, you should delete the datum from targets or properly reference the datum in a DRF.