Siemens 6FX1131-3BC02 is a SINUMERIK 850/880 bus module board that serves as the backplane to operator panel interface in legacy Siemens CNC systems. Marketed as a BUS MODULE OPERATOR PANEL, this plug-in board provides the essential bus connection for the SINUMERIK 850/880 controller family and is cataloged under 6FX1131-3BC02 (also seen as 6FX11313BC02) by multiple suppliers for replacement or refurbishment. Used in SINUMERIK 850/880 equipment to support the front-end control panel communications, it is typically sought for maintenance or retrofit of older Siemens CNC installations.
