Technical Literature

Line, bit and resolution concepts of incremental encoders

2022-09-19

Incremental encoder line, bit, the concept of resolution I. Incremental encoder line Encoder disk of the week engraved line, incremental disk engraved line can be 10 lines, 100 lines, 2500 lines of engraved lines, as long as the disk can be engraved, you can choose the number of; Absolute value of the disk of the disk engraved line due to the Gray code arrangement of the way the method, decided to decide that it is basically a power of 2 lines, such as 256 lines, 1024 lines, 8192 lines, etc. SSI signal conversion monitor through the coupling and other coupling parts of the encoder shaft and the measured shaft synchronous rotation. SSI signal conversion monitor through the coupling and other coupling parts will be the encoder shaft and the drum shaft or pinion shaft coupling, so that the encoder and the measured shaft synchronous rotation, the measured shaft rotation into the encoder shaft rotation, through the special tester to collect the encoder value so as to accurately measure the displacement of the measured parts. And achieve the purpose of real-time measurement and control of the displacement of the measured parts. It is suitable for measuring the lifting height of all kinds of windlasses and screw closure gates. But the absolute value code disk also has special Gray residual code output, such as...

Basic waveform and circuit analysis of incremental encoders

2022-09-19

Basic waveform and circuit analysis of incremental encoders Incremental encoders are sensors that output in the form of pulses. The outer and middle channels of the code disk of an absolute encoder have the same number of uniformly distributed light-transmissive and light-impermeable sectors, but the two sectors are staggered by half a sector from each other. When the code disk rotates, its output signals are the phase A and B pulse signals with a phase difference of 90° and the pulse signal generated by the third code channel with only one light-transparent slit. From the phase relationship between the A, B two output signals can be judged from the direction of rotation (direction). When the code disk is rotating positively, the pulse waveform of channel A is π/2 ahead of channel B, and when it is rotating negatively, the pulse of channel A lags π/2 behind channel B. The actual circuit is to use the positive pulse generated by triggering the monostable at the lower edge of the plastic waveform of channel A to phase with the plastic waveform of channel B. When the code disk is rotating positively, only the forward pulse of the mouth is output, and vice versa, only the reverse pulse of the mouth is output. The binary encoder is based on the input...

Incremental Encoder Resolution, Multiplication and Subdivision Technology

2022-09-19

Incremental encoder resolution, frequency multiplication and subdivision technology Incremental encoder code disk is composed of a very large number of grating engraved lines, there are two photoeyes to read the A, B signal, the density of the engraved lines determines the resolution of this incremental encoder, that is, the smallest change in the angle of the value of the disc can be read. The parameter that represents the resolution of an incremental encoder is PPR, which is the number of pulses per revolution. Incremental encoder A/B output waveforms generally have two kinds, one is a steeply rising edge and steeply falling edge of the square wave signal, a slow rise and fall, waveforms similar to sinusoidal Sin/Cos curve waveform signal output, A and B difference of 1/4 T period 90 degrees phase, if A is a class of sinusoidal Sin curve, then B is a class of cosine Cos curve. For square wave signals, A,B two phases differ by 90 degrees phase, so that at 0 degrees phase angle, 90 degrees, 180 degrees, 270 degrees phase angle, these four positions have rising and falling edges,...

What are the absolute encoder measurement methods? With method introduction

2022-09-19

What are the absolute encoder measurement methods? With method introduction The resistance value meets the requirement. The contact between the center sliding end and the resistance body is good and the rotation is smooth. The single-turn absolute encoder measures the various engraved lines of the optical code disk in rotation to obtain a unique code, and when the rotation exceeds 360 degrees, the code returns to the origin, which is not in line with the principle of the absolute code uniqueness, and such encoder can only be used for the measurement within 360 degrees of the rotational range, which is called the single-turn absolute encoder. For absolute encoders with switches, the switching part should be accurate, reliable and flexible. Therefore, it is necessary to check the performance of the absolute encoder before use. Here are some methods to measure the absolute encoder: 1, resistance measurement: first of all, according to the size of the measured absolute encoder resistance, select the appropriate resistance gear of the multimeter, measure the resistance, that is, the resistance between the two end pieces of the AC, compared with the nominal resistance, to see if they are the same. Meanwhile, rotate the...

About encoder output signals

2022-09-17

Rotary encoder is used to measure the speed of the device, everyone in the actual operation of the application process, will come into contact with the rotary encoder output signal type, I do not know whether you know these types? Today to popularize (refers to all over, throughout the general) under this knowledge. General encoder output signal in addition to the A, B two-phase, every turn also output a zero pulse Z. SSI signal conversion display is suitable for all kinds of winch, screw starter gate lifting height measurement. When the spindle rotates in clockwise direction, it outputs pulses according to the following figure, and the signal of A channel is located before the B channel; when the spindle rotates counterclockwise, the signal of A channel is located after the B channel. The signal of channel A is located before channel B. When the spindle rotates counterclockwise, the signal of channel A is located after channel B. Thus, it can be determined whether the spindle is rotating forward or reverse. Zero Position Signal of Rotary Encoder The encoder sends out one pulse for every one-week rotation, which is called zero pulse or mark pulse, and the zero pulse is used to determine the zero position or mark position. The zero pulse is used to determine the zero position or marking position. The zero pulse is measured accurately regardless of the direction of rotation...

Four types of delayed introduction to absolute encoders

2022-09-17

Encoder latency depends on the bandwidth of the analog (definition: a virtualization of a real thing or process) amplifier, its internal interpolating interpolation processing, resolution, and the encoder interface it uses. I. Interpolation interpolator delay If the analog encoder signal sine/cosine interpolation interpolation interpolation is an MCU/DSP based system, the delay period may exceed 200us or more. Particular attention should be paid when higher frequencies and resolutions are used, especially for synergistic multi-axis control and redundant systems. In such cases, delays can cause (enable, enable) position data to be perhaps not current or not synchronized. To meet this challenge, an ultra-fast flash-based interpolating interpolator can take on this task. iC-NV is a parallel internal processing, can be obtained with a delay of less than 1us interpolating interpolator. Encoder Interface Latency When a serial encoder interface is used, it is the data transfer time that usually only plays an important role. Absolute encoders ...

Encoder Installation: Connecting Absolute Encoders to PLCs

2022-09-17

As we know, absolute encoder encoder is a kind of rotary measurement device, it will be measured by the angular displacement directly into a digital signal. Therefore, we will be in the application of the rotary encoder output pulse signal directly into the PLC, the use of high-speed counter on the PLC pulse signal counting, in order to obtain the measurement results. It is important to note that the number of phases of the rotary encoder outputs is different for different models of rotary encoders! Some rotary encoders output A, B, Z three-phase pulses, some have only two phases, A and B, and the simplest has only A phase. Encoder mounting high-speed end mounting can fully use the full range and improve the resolution. Tie rope displacement sensor is a linear displacement sensor in the structure of the delicate composition, fully combines the advantages of the angle sensor and linear displacement sensor, to become a small installation size, compact structure, large measuring stroke, high precision sensors, the stroke from a few hundred millimeters to more than a dozen meters ranging. Application we will...

Encoder Installation Steps and Installation Precautions

2022-09-12

Encoder is a precision measurement of angular displacement based on the principle of electromagnetic induction sensor, can be used to measure the speed of mechanical devices can also be used for speed regulation of mechanical devices, and sometimes the speed of machining needs to be changed can use the encoder to work. Then how to correctly install the encoder it Encoder installation installed after the installation of reduction gear, such as the shaft end of the winch rope drum or the last section of the reduction gear shaft end, this method has been no gear back and forth clearance, the measurement of the more direct, higher precision, this method is generally measured over long distances, for example, a variety of lifting equipment, feeding trolleys positioning. Absolute encoder code value" with the measured "position" corresponds to a unique, with "power failure memory" function, no rotary measurement of accumulated errors, in "a cycle of "It is superior to the incremental encoder in the field of measurement and control, and the range can be adjusted by adding a front reduction gearbox. The encoder also has a shielded wire, the use of the shielded wire should be grounded to improve anti-interference. Encoder installation steps and ...

Absolute encoders allow control of a wide range of motor motors.

2022-09-12

Absolute encoders for detecting (checking and testing) the position and speed of rotary motion systems. Absolute value encoders allow closed loop control of a wide variety of motor control applications such as switched reluctance motors and AC induction motors. A typical absolute value encoder consists of a slotted wheel placed on a motor drive shaft and a transmitter/detector module for detecting (checking and testing) the slots on that wheel. Absolute encoders are widely used in water conservancy, light industry, machinery, metallurgy, textile, petroleum, aviation, marine and other industries. Specific to the project category such as: rotary table, gate opening, valve opening, hoist crane positioning, traveling crane positioning, level measurement, missile launch angle positioning, missile air rudder measurement, electronic latitude and longitude and other high-precision measurement and positioning occasions. Typically, there are three outputs, namely: phase A, phase B and index, and the information provided can be received to provide information about the motion of the motor shaft, including distance and direction. ...