Gemple's question and answer about mechanical absolute encoders and electronic encoders

Shanghai Jingpu Mechanical & Electrical Co., Ltd

(@Q)

1. What is the absolute value?

"Absolute value" refers to a measurement that is independent of previous readings and directly represents the position relative to the origin. It differs from "relative value," which is based on the previous position. The "absolute value" provides a unique reading every time, regardless of past measurements.

2. What is absolute value encoding?

Absolute value encoding ensures that each mechanical position within the sensor's range has a unique code corresponding to the origin. This means that even if the device is not moving, it can output a distinct absolute code. Unlike relative systems, it does not depend on historical data or accumulated counts.

3. What is the difference between "absolute" and "absolute value encoding"?

"Absolute" refers to the output of the receiving device, indicating the position relative to an external reference point. "Absolute value encoding," however, relates to the internal coding mechanism of the sensor, where each position is uniquely encoded without relying on previous readings. The term "encoder" should be based on its internal code reading principle.

4. What is an absolute single-turn encoder?

A single-turn absolute encoder provides a unique code for each position within a 360-degree rotation. After completing one full turn, the data resets. For example, the GAS60 series by GEMPLE offers high-resolution optical and magnetic encoders.

5. What is an absolute multi-turn encoder?

An absolute multi-turn encoder not only provides unique codes within a single rotation but also maintains this uniqueness across multiple rotations. These encoders use mechanisms similar to clock gears, ensuring accurate multi-turn position tracking. The GMX425 series from GEMPLE is an example.

6. What is electronic "absolute"?

Electronic "absolute" systems may appear to provide absolute values, but they rely on memory or movement to retrieve data. This makes them either "dynamic" (requiring motion) or "static" (using stored data). However, these are not true absolute encoders, as they depend on previous readings or power sources.

7. What are the issues with electronic absolute encoders?

Electronic absolute encoders are prone to errors due to memory loss, power failure, or interference. They may accumulate errors over time, making them less reliable than true absolute encoders. These systems are not suitable for critical applications like safety monitoring.

8. What is a gear-type absolute multi-turn encoder?

Gear-type encoders use mechanical gear sets to track multiple turns. Each position is uniquely coded, eliminating the need for memory. This design ensures accuracy across large measurement ranges, such as in industrial automation systems.

9. What is an electronic multi-turn "absolute" encoder?

Electronic multi-turn encoders combine absolute single-turn encoding with electronic counting. While they offer flexibility, they still have limitations, such as reliance on batteries or memory. These systems are not fully "absolute" and require careful application.

10. What is a Wiegand effect encoder?

Wiegand effect encoders use a special wire that generates voltage spikes when exposed to a magnetic field. They are used in low-power environments but are susceptible to interference and limited in accuracy. These are not true absolute encoders.

11. What is a full-stroke multi-turn absolute encoder?

Full-stroke encoders provide absolute encoding throughout the entire measurement range, ensuring no loss of accuracy during multiple rotations. These are ideal for applications requiring long-range precision.

12. What are absolute single-turn encoders?

GEMPLE offers optical and magnetoelectric single-turn encoders, including the GAS60 and GMS412 series. These encoders support various output signals like SSI, RS485, and CANopen.

13. What are absolute multi-turn encoders?

GEMPLE’s multi-turn encoders, such as the GAX60 and GMX425 series, provide full-stroke absolute encoding without internal electronics or batteries. These are designed for high reliability in industrial settings.

14. What is a smart encoder?

GEMPLE’s smart encoders feature a built-in MCU and software like Easypro. They support digital outputs, analog signals, and fieldbus communication, enabling intelligent control and IoT integration.

15. What is the analog output of an absolute encoder?

Absolute encoders can output analog signals like 4-20mA or 1-5V. These are useful for applications requiring continuous feedback, such as angle or speed measurement.

16. Why doesn't the analog output start at "0"?

Analog outputs typically start at 4mA or 1V to avoid confusion with zero signal interference. This ensures reliable detection of the actual position.

17. What output signals are available for GEMPLE’s absolute encoders?

GEMPLE offers a wide range of output signals, including 4-20mA, 1-5V, RS485, CANopen, Modbus, and more. Custom options are available upon request.

Shanghai Jingpu Electromechanical Co., Ltd. adheres to German technology standards, ensuring high reliability and accuracy. With over 5 years of stable performance in global projects, our encoders are trusted for critical industrial applications.

For more information, contact Shanghai Jingpu Electromechanical Co., Ltd.