Absolute encoders Advantage！

Absolute encoders Advantage

Rotary encoder incremental encoder output pulse is rotated by a counting device to know its position when the encoder does not move or power outage, counting on internal memory to remember the location of the device. Thus, when the power failure, the encoder does not have any movement, when work calls, encoder output pulse process, it can not have lost the pulse interference, otherwise, it will count zero offset memory device, and this bias the amount of shift is no way to know, to know only after the wrong production results appear. The solution is to increase the reference point, the encoder after every reference point, the reference position correction position count into the memory device. In the previous reference point, it is not guarantee the accuracy of the location. To this end, every operation in the industrial in there to go first reference point, turn the change and other methods. Such methods for some industrial projects too much trouble, not even allowed to give change boot (boot will know the exact location), so there is an absolute encoder appears.

Since the absolute encoder positioning clearly superior to incremental encoder, has been increasingly used in industrial targeting. Absolute encoders because of its high accuracy, the output bit more, if you still use parallel outputs, each of which an output signal of the need to ensure a good connection, but also for more complex conditions isolation, the number of multi-core cable connection, thereby inconvenience and reduced reliability, and therefore, the absolute encoder multi-bit output type, generally use the serial output or bus output, the German production of absolute encoder is the most common serial output SSI (synchronous serial line output) from a single-turn absolute encoder to a multi-turn absolute encoder rotary single-turn absolute encoder to rotate the measuring optical encoder each track groove to obtain a unique code, rotating more than 360 degrees when, coding back to square one, so not only in line with the principle of the absolute encoder, this encoder can only be used to rotate 360 ​​degrees within the range of measurement, known as single-turn absolute encoder. If you want to measure more than 360 degrees of rotation, it is necessary to use multi-turn absolute encoder.

Installation

Absolute rotary encoders Mechanical installation: Absolute rotary encoder attached to the high-speed side mechanical installation, low-end installation, auxiliary machinery installations and other forms. High-speed side installation: to the power of the motor shaft end (or geared), the advantage of this method is high resolution, due to the multi-turn encoder is 4096 revolutions, motor rotation number within this scale range, can be improved with a full range of foot resolution, disadvantage is that after the moving object through a reduction gear, a gear clearance to return an error, generally used for one-way high-precision positioning control, such as rolling roll gap control. Further encoder mounted directly on the end of a high speed, the motor must be less jitter, or easy to damage the encoder. Low-end installation: After the reduction gear, such as wire rope winch drum shaft or a final reduction gear shaft, this method is no longer to gear backlash, more direct measurement, high precision, this measuring method is generally long positioned at a distance, for example, various lifting equipment, feed carriage positioning.

working principle

Both are generally applied to the detection element speed control or position control system. The rotary encoder is used to measure the speed of the device. It is divided into single output and dual output two kinds. Technical data pulse count (there are a few to several thousand) per revolution, and power supply voltage. Single Output refers to the output of the rotary encoder is a pulse, and the rotary encoder output pulses two dual output phase difference of 90 degrees, by these two groups can not only measure the speed pulse, can also determine the direction of rotation. Incremental encoder and absolute encoder such as the distinction between the encoder signal to the principle points, incremental encoders, absolute encoders.

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