Renishaw: Linear Absolute Magnetic Encoder LA11

LA11 is an absolute magnetic linear encoder system designed for motion control applications as a position and velocity control loop feedback element. The encoder system is highly reliable due to contactless absolute measuring principle, built-in safety algorithms and high-quality materials/components used.

The measuring standard is a magnetic scale which consists of a stainless-steel substrate with an elasto-ferrite layer. The elasto-ferrite layer is magnetised with two tracks. The incremental track is magnetised with 2 mm long (alternating south and north) poles and the absolute track is magnetised with a pseudo random binary sequence (PRBS) absolute code with 13-bit length. The elasto-ferrite layer is immune to chemicals commonly found in industry.

The readhead includes Hall sensor arrays for PRBS track reading, an AMR sensor for incremental track reading, interpolation electronics and custom logic circuitry. The data from the Hall arrays and interpolator are processed in the internal MCU using special algorithms to determine the absolute position.

The electronics design provides short response and recovery times. Diagnostic information is available through a serial communication channel and status LED.

For applications which demand that the AS scale can be removed easily please consider TRS track system.

Features

• True absolute system
• Suitable for highly dynamic control loops
• Small footprint
• High accuracy
• Resolutions up to 0.244 µm
• Axis lengths up to 16.2 m
• Speeds up to 7 m/s at 0.977 µm resolution
• Integral status LED
• Synchronous (SSI, SPI, BiSS) communication protocols available
• Parallel incremental output (analogue or digital)
• Double shielded, drag-chain compatible cable
• Simple and fast installation
• Robust measuring principle
• Excellent degree of protection to IP68