What is the resolution of the Balluf encoder? How does an encoder distinguish between good and bad?

The quality of the Balluf encoder needs to be comprehensively considered in terms of appearance, output signal stability, and measurement accuracy. Dealing with encoder faults requires starting from aspects such as connection lines, power supply voltage, driver programs, or firmware updates.

I hope this article can be helpful to you, ensuring the normal operation of the encoder and extending its service life.

The Balluf encoder is a component of modern industrial equipment, but some problems are inevitable during use. This article will provide you with a detailed introduction on how to judge the quality of an encoder and how to handle encoder faults.

1、 How to judge the quality of the encoder

1. Observe the appearance: Firstly, carefully inspect the appearance of the encoder. High quality encoders are usually finely crafted with no obvious scratches or damage to the casing. If the appearance of the encoder is rough and flawed, there may be quality issues.

2. Check the stability of the output signal: Use professional equipment to detect the output signal of the encoder. A good encoder should be able to output signals stably and accurately. If the signal fluctuates greatly or is unstable, it indicates that the quality of the encoder may be poor.

3. Measurement accuracy: Use precise measuring equipment to check the measurement accuracy of the encoder. High precision encoders can provide more accurate position and velocity feedback information. If the measurement results differ significantly from expectations, it may be necessary to consider replacing the encoder.

2、 Fault handling method for Balluf encoder

1. Check the connection line: When the encoder malfunctions, first check whether the connection line of the encoder is normal. Loose, damaged, or poorly connected wiring can all cause abnormal operation of the encoder. Therefore, ensuring that the line connection is stable and intact is the first step in troubleshooting.

2. Check the power supply voltage: The encoder requires a stable power supply. If the power supply voltage is unstable or too low, it may cause the encoder to malfunction. Therefore, when troubleshooting, it is necessary to ensure that the power supply voltage meets the requirements of the encoder.

3. Updating drivers or firmware: Sometimes, encoder issues may be related to mismatched driver or firmware versions. Trying to update the encoder's driver or firmware to the latest version may solve some potential issues.

4. Seek professional repair or consultation: If none of the above methods can solve the problem, it is recommended to contact the encoder manufacturer or professional repair organization for further inspection. Damaged components may need to be replaced or further repairs may be required.

The encoder converts angular displacement or linear displacement into electrical signals, the former is called a encoder and the latter is called a line gauge. According to different reading methods, encoders can be divided into two types: contact type and non-contact type; According to the working principle, encoders can be divided into incremental and absolute value types. The incremental encoder converts the displacement into a periodic electrical signal, which is then converted into count pulses. The magnitude of the displacement is represented by the number of pulses. Due to the fact that each position of the absolute encoder corresponds to a determined numerical code, its displayed value is only related to the starting and ending positions of the measurement, and is not related to the intermediate process of the measurement.

The operating principle of the encoder:

Four sets of sine wave signals will be read and obtained by the optical transceiver device and combined into a, b, c, and d. Each sine wave will have a 90 degree phase difference (360 degrees relative to one frequency), and the c and d signals will overlap in reverse on the a and b phases, thereby enhancing stable signals; Each revolution outputs a z-phase pulse representing the zero reference position.

Due to the 90 degree difference between phase a and phase b, the forward and reverse rotation of the encoder can be determined by comparing whether phase a is ahead or phase b. The zero reference bit of the encoder can be obtained by zero pulse. The materials of the pulley are glass, metal, and plastic. The code wheel is a thin dividing line stacked on the glass, with good thermal stability and high accuracy. The rope wheel can be directly connected without marking lines, which is not easy to damage. However, due to the thickness of the metal, the accuracy is limited, and its thermal stability is one order of magnitude worse than glass. The rope pulley is economical and cost-effective, but its accuracy, thermal stability, and lifespan are all poor

Resolution - The number of open or dark lines provided by an encoder for each 360 degree rotation is called resolution, also known as analysis division or direct division into lines. It is usually divided into 5-10 thousand lines per rotation.

How to judge the quality of the encoder

The method to determine if the Balluf encoder is damaged is to connect it with the correct wiring. If AB does not have pulse output, it proves to be faulty. The quality of functionality mainly depends on the resolution. It is the number of internal dark engraved lines. The higher the resolution, the better, but the price is relatively high. Additionally, regarding the quality, it is recommended not to buy counterfeit products that are too cheap. There are many Japanese products used in the Chinese market now, as well as Korean ones. Famous manufacturers of PLCs, frequency converters, and servo motors have encoder products. Regarding which brand to choose, please move the samples and manuals up and down on them. Of course, it can also be obtained directly from the agent.

Connect to the PLC and check if the pulse count or code value is correct;

Connect the oscilloscope to observe the waveform

Test whether the output is normal using the voltage range of a multimeter.

When the Balluf encoder is an NPN output, measure the positive pole of the power supply and the signal output line. When the transistor is turned on, the output voltage is close to the supply voltage, and when the transistor is turned off, the output voltage is close to 0V. When the encoder is a PNP output, measure the negative pole of the power supply and the signal output line. When the transistor is turned on, the output voltage is close to the supply voltage, and when the transistor is turned off, the output voltage is close to 0V.

What is the resolution of a rotary encoder?

Resolution, also known as bit count, pulse count, or line count, is the number of pulses output by an absolute value encoder when the shaft rotates one revolution. In an absolute value encoder, it is equivalent to dividing one 360 degree circle into several parts. For example, if the resolution is 256P/R, every 1.4 rotations will divide one 360 degree circle into 256 parts

Output 1 code value to the left and right. The unit of resolution is P/R.

How to judge the quality of a speed encoder

1. When the encoder is stationary, the measurable a and b phase voltages are around 15V or 0V.

When using the Balluf encoder, the above two voltages should be obtained alternately. According to A - and B -, a voltage of 0V or -15V can be obtained.

2. When the encoder rotates continuously, the output may obtain the average effective voltage value, but only a stable voltage value of around 3-5V can be obtained.

3. A multimeter can only perform rough checks, and if the measurement results differ too much from the above instructions, it is preliminarily believed that the encoder is faulty.

4. However, relying solely on a multimeter cannot accurately check if the encoder is functioning properly.

Encoders typically output high-frequency pulse signals, so it is recommended to use an oscilloscope for measurement.

5. The method is to connect the output A-phase or B-phase signal of the encoder to an oscilloscope, and then rotate the encoder shaft. At this point, if a high-frequency 15V square wave pulse signal is observed using an oscilloscope, the encoder will improve.

Additionally, use a multimeter to test the voltage range to see if the output is normal.

When the encoder outputs NPN, measure the positive pole of the power supply and the signal output line,

When the transistor is turned on, the output voltage is close to the supply voltage, and when the transistor is turned off, the output voltage is close to 0V. When the encoder outputs PNP, measure the power supply negative sum signal output line,

The output voltage when the transistor is turned on is close to the supply voltage, and the output voltage when the transistor is turned off is close to 0V

Remove the encoder and rotate it by hand while continuously powered on, while viewing the data displayed on the screen. If the data remains unchanged, the encoder is faulty. If there are any changes, it proves that the encoder is very good

Balluf encoders generally require live monitoring. If the encoder can be disassembled, please turn the encoder by hand after connecting the power.