The difference between hengstler incremental encoder and absolute encoder

HENGSTLER type encoders are generally open collector output, voltage output, or linear output. The output is A phase, B phase, Z phase pulse, etc. Generally, if you want to record the position after power off, you can use it. The type encoder, the incremental encoder can be connected to the PLC with high counting function, or it can be connected to the commonly used counter. The absolute encoder output is binary code or Gray code, even if it is powered off. Record the current position. The absolute encoder needs to access the absolute encoder interface board such as CQM1H-ABB21. The high-count counter of the ordinary PLC cannot be connected to the absolute encoder. Or if the operating frequency is not very high, and the voltage is consistent. Specifications, the absolute value encoder can also be connected to the ordinary input point of the PLC, programmed through the program according to the specifications of the encoder output code, you can also use the incremental encoder: from a central optical encoder with a shaft, its There are circular pass and dark engraved lines, and there are photoelectric emission and receiving device readings. Four sets of sine wave signals are combined into A, B, C, and D. Each sine wave is 90 degrees out of phase (relative to one cycle). 3 60 degrees), the C and D signals are reversed, superimposed on the A and B phases to enhance the stable signal; and each Z-phase pulse is output per revolution to represent the zero reference position. Since the two phases A and B are 90 degrees out of phase, the encoder can be obtained by comparing the A phase before or the B phase to determine the forward and reverse rotation of the encoder, and the zero reference pulse can be used to obtain the zero reference position of the encoder. Absolute encoder: There are many optical channel engraving lines on the absolute encoder optical disc. Each line is arranged in 2 lines, 4 lines, 8 lines, 16 lines... so that in every position of the encoder, By reading the pass and dark of each reticle, a set of unique binary codes (Gray code) from the zeroth power of 2 to the n-1 power of 2 is obtained. This is called an n-bit absolute encoder. . Such an encoder is determined by the mechanical position of the optical code disc, and it is not affected by power outages and interference. Absolute encoders are unique in each position determined by the mechanical position. They do not need to be remembered, do not need to find a reference point, and do not have to count all the time, when to know the position, and when to read its position. In this way, the anti-jamming characteristics of the encoder and the reliability of the data are greatly improved. It can be seen from the above description that both have advantages and disadvantages, and the HENGSTLER incremental encoder is more common, and this is used in most occasions. From the price point of view, in general, the HENGSTLER absolute encoder is much more expensive, and the absolute encoder has a range, so it is generally applied on special machines.