A detector holder for a flat panel x-ray detector has a mechanical plug interface that allows flat panel x-ray detectors of respectively different types to be connected to and held by the detector holder. An x-ray system equipped with such a detector holder can be used flexibly for different applications respectively requiring different types of flat panel x-ray detectors. The type of the flat panel x-ray detector currently retained by the detector holder can be automatically detected and used by the data processor that processed output signals from the currently-employed flat panel x-ray detector.