Geometry and logical description of a detector module. Many detectors consist of multiple smaller modules. Sometimes it is important to know the exact position of such modules. This is the purpose of this group. It is a child group to NXdetector. Note, the pixel size is given as values in the array fast_pixel_direction and slow_pixel_direction. A dimension-2 or dimension-3 field which gives the indices of the origin of the hyperslab of data for this module in the main area detector image in the parent NXdetector module. The data_origin is 0-based. The frame number dimension (np) is omitted. Thus the data_origin field for a dimension-2 dataset with indices (np, i, j) will be an array with indices (i, j), and for a dimension-3 dataset with indices (np, i, j, k) will be an array with indices (i, j, k). The :ref:`order <Design-ArrayStorageOrder>` of indices (i, j or i, j, k) is slow to fast. Two or three values for the size of the module in pixels in each direction. Dimensionality and order of indices is the same as for data_origin. Offset of the module in regards to the origin of the detector in an arbitrary direction. Three values that define the axis for this transformation A fixed offset applied before the transformation (three vector components). Units of the offset. Points to the path of the next element in the geometry chain. Values along the direction of :ref:`fastest varying <Design-ArrayStorageOrder>` :index:`pixel direction<dimension; fastest varying>`. Each value in this array is the size of a pixel in the units specified. Alternatively, if only one value is given, all pixels in this direction have the same value. The direction itself is given through the vector attribute. Three values that define the axis for this transformation A fixed offset applied before the transformation (three vector components). Units of the offset. Points to the path of the next element in the geometry chain. Values along the direction of :ref:`slowest varying<Design-ArrayStorageOrder>` :index:`pixel direction<dimension; slowest varying>`. Each value in this array is the size of a pixel in the units specified. Alternatively, if only one value is given, all pixels in this direction have the same value. The direction itself is given through the vector attribute. Three values that define the axis for this transformation A fixed offset applied before the transformation (three vector components). Units of the offset. Points to the path of the next element in the geometry chain.