Composite tolerance for a pattern of holes WITH a cutout? 2

[BrandonR]

I have a pattern of 2 holes and a rectangular cutout I want to control on a bracket (electrical connector mounting). I figure a composite tolerance is appropriate to more tightly control the pattern of the 2 holes and cutout together, compared to the part's larger datum scheme.

I understand how to apply a composite tolerance to the 2 holes' position FCF but I'm confused how to apply it to the cutout's profile FCF. What's the best way to notate that the profile should apply relative to the holes? Do I set the holes as a new datum (C) and use that datum on the cutout's profile (A|C)? Or what?

Feel free to critique other aspects of this (incomplete) drawing.

 

[greenimi]

Maybe add A primary on the lower profile segment and add SIM REQT under the feature control frame (of the profile and lower segment of the composite)

 

[CheckerHater]

Something like this:

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[Burunduk]

BrandonR,
A simple, default simultaneous requirement like the one shown in the fig. 4-39 example posted by CheckerHater will only apply for the top segment of the composite position FCF and the profile FCF (when it references the same datums in the same order as the top segment of position). The ASME Y14.5 standard specifies that a simultaneous requirement between different features and/or patterns is not applicable to the lower segments of composite FCFs, unless SIM REQT is specified as suggested by greenimi. So by default, the features will be allowed to vary relative to each other within the looser tolerances that relate them to datums A and B. 

For a tighter control between the two holes and the cutout, it is necessary to do either what greenimi suggested, make the two holes datum C and control the cutout with reference to A,C as you thought, or make the width of the cutout datum feature C and the internal edge of the cutout datum D, and control the two holes by position referencing A,C,D.