8.A121.6832.3113 Profibus Encoder with AX Ø16 mm Hollow-Shaft Adapter

For 8.A121.6832.3113, EncoderWorks can provide a custom compatible replacement solution for large-shaft Profibus absolute feedback systems where the key checks are AX ø16 mm bore fit, encoder-side locking-ring position, 70 mm torque-arm preload, Profibus-DP scaling, and M12 network wiring. This model should not be treated like a standard 58 mm shaft encoder, because the feedback unit is built around a Kübler AX hollow-shaft adapter and a Sendix 5868 Profibus multiturn encoder. Typical production lead time: 15 working days.

This configuration is used where a Profibus absolute encoder must be mounted directly on a larger machine shaft rather than through a small solid-shaft coupling. The AX section provides a ø16 mm hollow-shaft adapter, encoder-side clamping, and 70 mm torque arm, while the matched Sendix 5868 encoder provides Profibus-DP V0 Class 2 absolute position feedback through three radial M12 connectors. Replacement work should focus on shaft fit, clamping torque, torque-arm alignment, Profibus address, GSD configuration, scaling, preset behavior, and shield continuity.

System Limits

The first system limit is mechanical. The ø16 mm shaft must match the AX adapter bore without forcing the clamp, and the locking ring must be positioned on the encoder side as specified by the “A1” configuration. Excess clamp force, shaft runout, or torque-arm preload can create bearing stress, housing movement, or repeatability drift.

The second limit is Profibus configuration. The PLC must recognize the replacement as the correct Profibus-DP encoder class and preserve the original address, GSD file, scaling, preset value, and counting direction. If the bus is online but scaling or profile data is different, the axis may report a valid position with the wrong mechanical value.

The third limit is AX operating envelope. The AX adapter is rated IP64 and its allowable speed depends on operating temperature. High shaft speed, high ambient temperature, or poor torque-arm alignment can become the real failure boundary before the electrical interface fails.

Wiring & Installation

Before replacement, record the Profibus node address, GSD configuration, preset value, scaling parameters, direction setting, and diagnostic behavior from the controller project. Also record the three M12 connector assignments for Profibus bus, power supply, and service or auxiliary wiring.

During installation, confirm the ø16 mm H7 shaft fit, set the locking ring on the encoder side, and align the 70 mm torque arm without preload. Keep the Profibus and power cables away from inverter output wiring, maintain shield continuity through the M12 connectors, and avoid ground loops between the encoder housing, machine frame, and cabinet earth. After startup, verify online bus status, actual position, direction, preset response, torque-arm movement, and repeatability over several machine cycles.

Custom Compatible Solution

EncoderWorks can configure the replacement around the installed shaft and Profibus system:

• Match the AX ø16 mm hollow-shaft adapter, encoder-side locking ring, 70 mm torque arm, and installation envelope
• Preserve Sendix 5868 Profibus-DP V0 Class 2 position feedback, GSD setup, scaling, preset, and direction behavior
• Adapt the three radial M12 connection layout, power supply range, shield grounding, and bus wiring
• Review clamping torque, shaft fit, torque-arm preload, IP64 installation limits, and temperature-speed operating margin

Key Data