Multiturn Absolute Encoder: Precision Position Tracking Across Multiple Rotations

A multiturn absolute encoder is an advanced sensor that delivers precise, unambiguous position feedback over multiple complete rotations of a shaft. Unlike single-turn absolute encoders—which only track position within a single revolution—multiturn absolute encoders record both the angular position within each turn and the total number of revolutions, making them indispensable for applications requiring continuous accuracy over long distances or complex movements.

What is a Multiturn Absolute Encoder?

A multiturn absolute encoder combines two core functions:

· Single-turn encoding: Measures the precise angular position within one 360° rotation.

· Multi-turn tracking: Counts and stores the number of full revolutions, enabling the system to know the exact position even after many turns or power cycles.

This dual capability is achieved through integrated gear mechanisms, electronic counters, or battery-backed memory, ensuring that the encoder retains position data even during power loss.

Key Features and Advantages

· Position Detection Over Many Turns:
Tracks position across up to 16 or even 24 bits of revolutions, allowing for tens of thousands or millions of unique positions.

· High Resolution:
Offers up to 23 bits per revolution (over 8 million positions per turn) and 16 bits for multi-turn (65,536 revolutions), as seen in products like the RZ35 series.

· Non-Volatile Memory:
Maintains position data after power loss, eliminating the need for re-homing or zero-point resets—crucial for efficiency and reliability in automation and robotics.

· Robust Communication:
Supports RS485, SSI, BiSS, fieldbus, and industrial Ethernet interfaces for seamless integration.

· Durable Design:
Operates reliably in harsh environments, with wide temperature ranges (e.g., –20°C to +105°C) and strong resistance to shock and vibration.

· Compact Options:
Available in small sizes (as compact as 16mm diameter), ideal for space-constrained applications.

How Does a Multiturn Absolute Encoder Work?

Multiturn absolute encoders use a combination of optical or magnetic sensing and mechanical or electronic counting. A primary disc tracks the position within one turn, while a secondary system (often gears or electronic counters) records the number of full rotations. This allows the encoder to output a unique digital code for every possible shaft position, spanning both angle and total turns.

Applications

Multiturn absolute encoders are essential in:

· CNC Machines:
Ensuring precise tool positioning over long travel distances and multi-step operations.

· Robotics and Automation:
Providing continuous, accurate feedback for multi-axis arms and automated guided vehicles (AGVs), improving stability and operational efficiency.

· Industrial Machinery:
Used in turntables, elevators, and material handling systems where position must be tracked over many rotations.

· Aerospace and Medical Devices:
Supporting high-precision, safety-critical applications requiring non-volatile position data.

Example: RZ35 Series Multiturn Absolute Encoder

The RZ35 series multiturn absolute encoder features:

· Resolution: 17 to 23 bits per turn (131,072 to 8,388,608 positions)

· Multi-turn Counter: 16 bits (up to 65,536 revolutions)

· Accuracy: Absolute positioning <±50 angular seconds; repeatability <±3 angular seconds

· Robust Design: –20°C to +105°C operating range, IP40 protection, and RS485 communication.

Why Choose a Multiturn Absolute Encoder?

· Immediate, accurate position feedback after power-up

· No need for homing or reference moves

· Ideal for long-travel, multi-step, or safety-critical applications

· High integration, reliability, and efficiency

> EPOCH ELECTRONIC specializes in supplying high-performance multiturn absolute encoders for servo motors and automation systems. Our encoders deliver unmatched precision, robust durability, and seamless integration—ensuring your equipment achieves the highest standards of accuracy and reliability.