Siemens 6FC5210-0DB22-3AA1 MMC103 is a SINUMERIK MMC103 controller module designed for the SINUMERIK 810D/DE and 840D/DE CNC systems. It combines 128 MB of DRAM with a Pentium 200 MHz open‑architecture PC, and in some listings Windows NT 4.0 is preinstalled under SINUMERIK 840D BS003, while other descriptions note the unit ships without system software. Also cataloged as 6FC52100DB223AA1, Siemens has discontinued this item and it is commonly sourced as refurbished or replacement hardware for legacy SINUMERIK installations.
