What it is and what it connects
The Siemens 3RK1911-0CR50 is a preassembled ECOFAST power cable interface for the ET 200X distributed I/O system. It carries 5 x 4 sqmm conductors and terminates in Han Q8 connectors on both the sensor (ST) and actuator (BU) sides. The cable is cut to any length between 3 and 5 meters, ordered in a 10 cm grid. This is a factory-assembled drop cable — no field termination required. The Han Q8 connector is the standard industrial rectangular interface for power and signal in the ECOFAST ecosystem, common on Siemens ET 200X remote I/O stations in conveyor, material handling, and machine-build applications.