Siemens 6FC5357-0BB15-0AA0 is the SINUMERIK 840D/DE CNC hardware NCU 571.5 module, a CNC control unit powered by a 400 MHz Celeron processor with 64 MB of memory (excluding system software), including CNC user memory of 3 MB and PLC memory of 128 KB. The unit is prepared for PROFIBUS DP communication and aligns with IEC 61508 safety specifications as noted by Siemens documentation. Siemens lists this MLFB as obsolete since November 16, 2020.
