Y14.5.1-2019 goes into great detail on single solution datums, including the constrained L2 math. Y14.5-2018 made a subtle change from previous revisions such that the new default method for stabilization is a single solution datum instead of the previous practice of the candidate datum set. Y14.5-2018 does not explicitly state "constrained L2", that is in Y14.5.1-2019.
Y14.5-2018 Para. 7.11.2 discusses the new default requirement being a single solution and refers you to Y14.5.1.
Am struggling a bit, hopefully you can set me straight.
Lets say I have an ABC alignment (PLN_A, CYL_B, CYL_C)
If I did a true position check of something back to ABC & I override "Datum Reference Frame" and select "Current Alignment"...
-Will PC DMIS look at -B- as the LEASTSQU type (because that's what it was probed as)..
OR... the L2 type (because we're doing all this fancy GD&T through XACT)?
DAN_M Are you using PC-DMIS 2020 R2? If so, the new Geometric Tolerance command allows you to choose the math type used to evaluate your datum features, namely Least Squares or Default (Constrained L2 if ASME).
If you are not using 2020 R2, I believe PC-DMIS will evaluate datum feature B using whichever fitting algorithm you used when probing the feature.
Changing between "Datum Reference Frame" and "Current Alignment" should not change the way that PC-DMIS evaluates anything, it should simply change the reporting coordinate system. If you set your (current) alignment per the datum reference frame [A|B|C], there should be no difference in the report by changing between the two options.
