The SYRMEP approach to digital mammography implies the use of a monochromatic X-ray beam from a synchrotron source and a slot of superimposed silicon microstrip detectors as a scanning image receptor. The microstrips are read by 32-channel chips mounted on 7-layer hybrid circuits which receive control signals and operating voltages from a MASTER-SLAVE configuration of cards. The MASTER card is driven by the CIRM, a dedicated CAMAC module whose timing function can be easily excluded to obtain data-storage-only units connected to different MASTERs: this second-level modular expansion capability fully achieves the tasks of an electronics system able to follow the SYRMEP detector growth till the final size of seven thousands of channels.