How to create Datum A-B using 2 parallel offset planes

[[WI...]]

I have a part to measure that has Position callouts back to datum A-B, 2 parallel planes 31mm apart. Not sure how to do this in Calypso. Have discussed with a few people, symmetry, plane with offset, offset planes where options but I question each method and how it was described to whether it follows asme. With offset plane seems can only pick 3 points, Not exactly sure what the plane offset gives me, can offset one plane the basic dimension to the other but not sure how calypso calculates the result. Symmetry also not sure how calypso will calculate result and will create what I assume is a best fit plane between the 2 planes.

[[WI...]]

Was given the following option which sounded ok to me but when Offset the one plane could not use recall feature points on the offset plane.

Datum A and Datum B then you will need to offset one plane the basic amount. There is more than one way to do this but one way is go to construction, plane with offset select Dtm B offset the Basic amount (31) in the direction of Dtm A pos or neg.
Once this is done now go to features, Plane then utilize recall feature points chose Dtm A and the Offset plane feature to create this plane this now becomes Plane A-B , and this can be utilized as a Alignment Feature.

[[Cl...]]

Features > Special Geometries > Offset Plane.

I believe this option was designed for this situation.

[[WI...]]

Features > Special Geometries > Offset Plane.

I get that to a point, but doesn't that feature just allow 3 points to be taken to create the feature. Doesn't seem to be very accurate in case one of the planes was really out of spec

[[WI...]]

To add to my response, what if you have 5 surfaces that make up datum A and 5 surfaces that make up datum B? Unless I don't understand the offset plane feature and I can select more then 3 points?

[[Ke...]]

These are always a headache for me. I'm usually only dealing with 4 mounting points, though...

Consider: using a Geometry Best Fit for all Datum Surfaces, and then using Maximum Coordinate for 3 locations (referencing the Geometry Best Fit) to get 3 points ... maybe consider the 3 circular Datum A Planes as a single Feature(?)

I would also do an initial Flatness evaluation of Datum A and B, and also see how they are, relative to one another