RKG5021 by Bosch Rexroth Indramat

Bosch Rexroth Indramat supplies the RKG5021, an encoder feedback cable in the RKG Encoder Cables series. The product links SSI-based position transducers to drive controllers and carries both power and differential clock lines in a single molded assembly. Used in machine tools and automated handling stations, it transmits encoder signals while the internal shielding helps reduce electromagnetic noise between the sensing element and the motion controller. This arrangement keeps the feedback path and encoder supply conductors within one cable run, which supports orderly routing in space-limited equipment.

The cable supports the serial synchronous interface through a dedicated pair marked as SSI, so controllers can poll absolute position data with minimal latency. Clock polarity is easy to identify because the Clk- conductor has a jacket coded Yellow/Black and the Clk+ line is colored Green/Black; this color scheme helps avoid wiring mistakes during installation. To feed the encoder electronics, a power pair with a cross-section of 0.34 mm² is included, providing low-resistance delivery of current over standard cable lengths. An internal screen surrounds all twisted pairs, forming a continuous shield that diverts high-frequency interference and helps maintain signal integrity when drives switch at high edge rates.

Mechanical termination on the sensor side is achieved with a 12-pin circular connector, so the harness mates directly with Rexroth absolute encoders that follow the common pinout. Within this plug, the reference return for logic lines is assigned to Pin 10 and kept at 0 V, while the regulated supply appears on Pin 12 at 5 V. Data channels use conductors of 0.14 mm², balancing flexibility with adequate impedance control for differential signaling. The molded connector layout keeps the signal and supply contacts grouped in a compact interface at the encoder end.