The field has rank 2, should be 4 for MCA spectrum detector data

[jkotan]

I would expect data of MCA spectrum detectors can be stored in NXdetector/data as
2D array. However, I get

            NXdetector: /scan/instrument/mca01
                Field: /scan/instrument/mca01/data
                    The field has rank 2, should be 4

[rayosborn]

This is a major issue that needs to be resolved by the NIAC. The base class definitions include a number of fields with rigidly specified ranks that should, I believe, be made variable. I plan to use NXValidate to highlight such issues, so thank you for raising it.