The absolute value encoder is a sensor that directly outputs digital quantities. There are several concentric code tracks along the radial direction on its circular code disk, each composed of transparent and opaque sector areas. The number of adjacent code tracks is a double relationship, and the number of code tracks on the code disk is the number of digits of its binary digits. On one side of the code disk is the light source, and on the other side, there is a photosensitive element corresponding to each code track; When the code disk is in different positions, each photosensitive element converts the corresponding level signal based on whether it is illuminated or not, forming a binary number. The characteristic of this encoder is that it does not require a counter and can read a fixed numerical code corresponding to the position at any position on the shaft. Obviously, the more code traces, the higher the resolution. For an encoder with an N-bit binary resolution, its code disk must have N barcode traces. At present, there are 16 bit absolute encoder products in China.

Absolute value encoder

Absolute encoders use natural binary or cyclic binary (Gray code) methods for photoelectric conversion. The difference between absolute encoders and incremental encoders lies in the transparent and opaque line patterns on the disk. Absolute encoders can have several codes to detect absolute positions based on the codes read on the encoder disk. The design of coding can adopt binary code, cyclic code, binary complement code, etc.

Its characteristics are:

1. It is possible to directly read the absolute value of angle coordinates;

2. No cumulative error;

3. The position information will not be lost after the power is cut off. But resolution is determined by the number of bits in the binary system, which means accuracy depends on the number of bits,

There are currently 10, 14, and other options available.