Annotation Family - Dimension does not snap to centreline

[Bastiat]

Hello,

I have made a floor waste family and want to dimension to its Centreline (so that the C/L mark automatically appears).

I can do this to 2D columns but it will not allow me to do it to the Floor Waste.

Does anyone know how to fix this?

Attached is a screenshot showing the dimension to column with C/L and the dimension to Floor Waste without the C/L.
FLOORWASTE.png

[Bastiat]

I forgot to mention that the Floor Waste is an Annotation Family while the column is a Detail Family. This may be my problem....

[Bastiat]

I still cannot dimension to the centreline of an annotative text (using automatic centreline). Any takers?

[greg.mcdowell]

You can't dimension to an Annotation Family.

[58D Pilot]

Why not? Maybe Im not understanding but I have built many annotative families that have a centerline reference plane which can be dimensioned to/ from.

[Bastiat]

I have set up my dimensions so that when I dimension to the centreline of a column the C/L symbol appears automatically.

I want it to do the same with my Floor waste which is drawn as an annotation family.

It is not allowing me to do this. Why not?