Signal Cable 6FX8002-2CA31-1BA0 6FX8 002-2CA31-1BA0 6FX8OO2-2CA31-1BAO

6FX8002-2CA31-1BA0 | Siemens Signal Cable — Incremental Encoder with C/D Tracks / 10m / M23 Full Thread / MOTION-CONNECT 800PLUS / UL/CSA

Encoder Cable for Motors with Integrated C/D Commutation Tracks

The 6FX8002-2CA31-1BA0 is a 10-metre pre-assembled signal cable from Siemens' MOTION-CONNECT 800PLUS range — designed for the specific combination of incremental encoder (ABR) and C/D commutation tracks integrated into a single motor-mounted encoder assembly.

This cable type differs from standard incremental encoder cables and resolver cables in one important way: it carries additional conductors (4×0.22mm²) for the C/D commutation tracks that the motor encoder provides alongside the standard incremental ABR signals. This combined feedback in one cable is characteristic of specific SIMOTICS motor configurations where the encoder assembly provides both incremental position counting and commutation data from a single connector.

Key Specifications

C/D Commutation Tracks — The Fourth Conductor Group

The distinguishing feature of the 6FX8002-2CA31 compared to simpler encoder cables is the 4×0.22mm² conductor group for the C/D tracks:

Standard incremental tracks (ABR): The 3×(2×0.14mm²) twisted pairs carry the standard incremental encoder A, B, and R (reference) differential signals — providing relative position counting (A/B quadrature) and one-per-revolution reference (R). These are present in all incremental encoder feedback cables.

C/D commutation tracks: The 4×0.22mm² conductors carry the C and D track signals — lower-resolution sinusoidal signals that span one full electrical period per motor pole pair rather than per shaft revolution. These signals provide the commutation information needed to determine the rotor's initial electrical angle at startup without a separate commutation sensor.

Why C/D tracks matter for synchronous servo motors: Permanent magnet synchronous motors require accurate knowledge of the rotor's electrical angle to generate correct torque from the first power cycle. Without C/D tracks, the drive must perform a homing or pole-finding sequence at each startup. With C/D commutation tracks from the encoder, the drive knows the initial electrical angle immediately — enabling direct torque control from the first PWM cycle.

Applications

CNC machine tool feed axes with combined encoder motors: SINAMICS S120-driven feed axes on machining centres, turning centres, and grinding machines using SIMOTICS servo motors with integrated incremental+C/D track encoders.

High-dynamic servo positioning: Servo axes requiring immediate torque from startup without a pole-finding sequence — the C/D commutation tracks enable zero-delay torque control, important for rapid acceleration axes.

CNC machine retrofit: Replacement encoder feedback cables on machines with SIMOTICS motors that include C/D track encoders — the 10m length covers medium cable track run distances.

FAQ

Q1: What SINAMICS module interfaces with the C/D encoder tracks in 6FX8002-2CA31?

The SINAMICS S120 SMC20 Sensor Module is the SINAMICS interface that processes incremental encoder signals with C/D commutation tracks. The 25-pin Sub-D connector of the 6FX8002-2CA31-1BA0 mates with the SMC20's encoder input socket. The SMC20 uses the ABR signals for position counting and the C/D signals for initial commutation — confirm from the SINAMICS S120 hardware documentation that the SMC20 is the correct module for the specific motor encoder type.

Q2: What is the difference between 6FX8002-2CA31 (C/D tracks) and 6FX8002-2CF02 (resolver)?

Both cables share the same outer diameter range and MOTION-CONNECT 800PLUS specification, but carry fundamentally different feedback signals. 6FX8002-2CA31 carries incremental encoder signals (digital quadrature + C/D sinusoidal) for motors with optical or magnetic incremental encoders. 6FX8002-2CF02 carries resolver signals (AC sinusoidal excitation and response) for motors with resolver position transducers. The motor's feedback device determines which cable type is required.

Q3: How does the 4×0.22mm² C/D conductor size relate to the signal type?

C/D track signals are low-frequency sinusoidal voltages — typically a few volts at a frequency proportional to shaft speed but with one electrical period per pole pair. The 0.22mm² conductors provide sufficient cross-section for the signal current levels involved. Individual shielding on these pairs (confirmed by the "C" designation) isolates the C/D signals from the higher-frequency ABR track signals in the same cable bundle — preventing high-frequency crosstalk from the encoder's ABR channels into the slower C/D channels.

Q4: Does 6FX8002-2CA31-1BA0 require any specific cable track spacing from power cables?

Encoder and resolver signal cables must be routed in the signal wiring section of the cable track, separated from motor power cables. Routing the 6FX8002-2CA31-1BA0 directly adjacent to a motor power cable introduces switching transient interference into the encoder signal conductors — potentially causing encoder counting errors or alarm conditions in the SINAMICS drive. Follow standard cable track wiring segregation practice: signal cables on one side, power cables on the other, separated by a divider.