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THINK they put that in, but maybe it isn't in yet. I don't see it in 2021.2 which I'm using.
Workaround, you have a cylinder called Cyl_A which is Datum A, and a cylinder called Cyl_B which is datum B. Adjust feature type and construction as required.
In case they didn't, you construct feature (let's say a cylinder) from (let's say) cylinders A and B, BFRE is my preference.
Then, you click in your code window and add .hits[1..Cyl_A.numhits] after Cyl_A and add .hits[1..Cyl_B.numhits] after Cyl_B in the code window for the feature construction.
Verify your constructed feature size, location and vectors didn't go wonky.
Assign this datum definition as A_B, AB, or whatever floats your boat.
Use that in your FCF.
If the sizes are different, I haven't ever found a step cylinder in PcDmis for some reason, so you have to use variable assignments to offset the hits of one of the features in the hit's vector to the diameter you want. This adds a fair amount of potential for error and false reporting, so be sure you are taking the hits as close to the correct position as possible (measure a cylinder, align it and zero it, measure it again so the hits are very very close to the correct spacing and normal to the cylinder surface). You want to be VERY sure you aren't screwing this up if you have to do it, and you want to run some correlation studies to replicating this on a surface plate before you take the results and run with them. But if you are extremely careful, diligent and conscientious it can be done. Without getting up and looking, I'm 100% sure mCosmos does a step cylinder and 85% Calypso does. PcDmis I can't find it.
Hopefully the standard thing with just making a cylinder will work. If the diameters are close, you can make the constructed cylinder from the hits without any offsetting, PcDmis will just think it is tapered.
Maybe they added it, and someone will tell you where it is and it will be a version you have access to, then you won't need a work around at all.
If you have any of the newer versions, create datum definition, select "create common datum", select your datums A and B, give it a name and hit create.
I incorrectly assumed (and did make an azz out of at least me in the process) that common datum was to use the feature with more than one datum definition.
I have on part in particular where a single bore is datum F, A and B all simultaneously. F is the bore, A is a plane and B is a plane perpendicular to A. I just assumed it wasn't only me, and that is what it was for.
I thought it was compound datum and I was missing it. Maybe I should read... but real Murican men don't read instructions!!!! just ask my ex-wife
