How can you use a tool to measure the moving distance, speed or angle of a rotating object? The answer is to use a rotary encoder. In this article, you will learn what an absolute rotary encoder is, types of absolute rotary encoders, how to choose a suitable absolute rotary encoder step by step, top absolute rotary encoder brands, and more. Let’s get started now.
What Is An Absolute Rotary Encoder?
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Hollow Shaft Incremental Rotary Encoder -
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Hollow Shaft Incremental Rotary Encoder -
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Incremental Rotary Encoder
A rotary encoder is a position sensor that converts the rotation angle or speed of a rotating object into a measurable and recordable electrical signal.
There are two main types of rotary encoders in the world, one is an incremental rotary encoder and the other is an absolute rotary encoder. Unlike incremental rotary encoders with periodic outputs, the output of absolute rotary encoders is unique and non-repetitive. This feature gives absolute encoders the advantage of not being affected by power failure, and they are often used to measure the rotation angle of a robotic arm, etc.
Absolute Rotary Encoder Applications
Absolute encoders are suitable for reliable/accurate measurement of height, travel, angle and speed of tower cranes, mining cranes, construction hoists, machine tools, 3D printers, automated assembly lines, industrial robots, printing machinery, packaging machinery, logistics machinery, mobile advertising screen slides and other equipment.
Absolute Rotary Encoder Types
Absolute rotary encoders can be divided into two types: single-turn absolute rotary encoders and multi-turn absolute rotary encoders.
Single-turn absolute encoders are suitable for measurements within a rotation range of 360 degrees, while multi-turn absolute encoders can measure rotations exceeding 360 degrees through the mechanical gear transmission principle, which is very useful for applications that require continuous rotation measurement.
Steps To Choose A Right Absolute Rotary Encoder
Step 1 Confirm the output resolution
The absolute rotary encoder resolutions are various in the market. The output pulse range of an absolute encoder can range from a few thousand pulse positions (such as 8192 positions for 13 bits) to millions or even tens of millions of pulse positions (such as 1073741824 positions for 30 bits).
For absolute rotary encoders: The higher the resolution, the more precise the measurement, but also the more expensive it is.
Step 2 Choose single-turn or multi-turn rotary encoder
As mentioned above, absolute rotary encoders are divided into single-turn and multi-turn. If you only want to measure the rotation angle within 360 degrees or a short distance, try to choose a single-turn absolute rotary encoder. If you want to measure not only the angle but also the speed or a long distance, a multi-turn absolute rotary encoder is the best choice.
Step 3 Selecting interfaces and communications
Absolute rotary encoder communication port types can be Profinet, EtherCAT, SSI, BiSS, RS485, CANopen, SPI, analog output.
These interfaces have their own characteristics and are suitable for different application scenarios and system requirements. Choosing the correct and appropriate communication interface is very important for your application, so please choose the correct communication port according to your needs.
Step 4 Confirming the mounting methods
The rotary encoder can be mounted by flange or leaf spring. Flange mounting has high connection strength and good air tightness, while leaf spring mounting has greater flexibility and can reduce the impact of vibration on the encoder(strong vibration might damage the code disc inside the rotary encoder, see this article: Encoder Problems With Solutions: The Ultimate Guide).
Step 5 Budget Consideration
Generally speaking, absolute rotary encoders are more expensive than incremental rotary encoders. As mentioned above, the higher the encoder resolution, the higher the price. So if you don’t need such precise data, please try to use low-resolution ones. If you want more precise monitoring and control, please try to choose high-resolution ones.
Top Absolute Rotary Encoder Brands
When considering how to choose the right absolute rotary encoder, the choice of brand is also crucial.
Choosing products from well-known brands means low risk, good quality and good after-sales service. There are many well-known absolute rotary encoder brands and manufacturers in the world, such as Sensata(USA), Dynapar (USA), AK Industries (France), SENTOP (China), Briterencoder (China), Renishaw plc (Indonesia), HEIDENHAIN (Germany), Baumer (Germany), KÜBLER (Germany), Tamagawa (Japan).
Conclusion
To sum up, we can choose a suitable absolute rotary encoder from the aspects of output resolution, number of absolute rotary encoder turns, communication port, installation method, budget, etc.
Lorentzzi® is a China incremental rotary encoder supplier, not only can provide the best quality hollow shaft incremental rotary encoder, but also can provide the best quality solid shaft incremental rotary encoder, please send your inquiry to shonxu@lorentzzi.com to get our professional advice and quotation!
