通用banner
Your current location: Home >> News >> Industry Information

Briefly understand the difference between the special grade, industrial grade and economic grade of CANopen absolute encoder

2021-04-28 H:05:07
second

Commercial and chip level:


For example, the encoders inside printers and magnetic card machines have a simple structure, and many shells are not available. There is almost no need to talk about temperature, dustproof, waterproof, electromagnetic compatibility, and the price is extremely cheap. Chip-level: The price is very low, provided by some foreign semiconductor chip manufacturers, or simply packaged by downstream manufacturers. The power and signal are only handled simply, which is suitable for the manufacturer's secondary circuit development. The distance between the receiving line and the encoder should not exceed 50 cm. Some manufacturers of flow meters and valve electric adjustments choose this level. The protection and electromagnetic compatibility anti-interference of this type of CANopen absolute encoder are the secondary development manufacturers to consider. If they don’t understand, it is easy to cause damage.


Economic grade and industrial grade:


Economic-level simple packaging and processing are suitable for stand-alone equipment, such as embroidery machines. However, economic-level is characterized by economical design and material selection, and is not suitable for large-scale equipment, assembly lines and engineering projects. The design, material selection and testing are all carried out in accordance with standard industrial requirements, and are suitable for various industrial equipment, assembly lines and engineering projects. The typical difference between these two grades can be seen from the appearance and parameter table


1. Tolerance


CANopen absolute encoders are single-bearing (some chip-level bearings do not use ball bearings). Some economic-grade bearings are externally fixed with clamps, and the clamp ring can be seen (as shown in the figure below). Some are smarter, adding a part in front of the bearing to cover the circlip. After a single bearing has been used for a period of time, the accuracy is naturally difficult to guarantee due to the single force, and the sealing performance is also poor. However, the industrial grade has a double ball bearing structure, multi-fulcrum balance, high shaft accuracy, impact resistance and good sealing performance. The double-bearing structure has high requirements on the machining accuracy and installation accuracy of the shaft, because if the accuracy is not enough, due to the interaction between the two bearings, there will be a feeling of "stuck" during rotation, so the shaft can only be held once. Can feel the accuracy of the shaft. The strange thing is that for some encoders with nominal "high precision", the bearing is also a single-bearing method, and I don't know how to ensure its "high precision" after long-term use.


2. Shell packaging


The economical housing is packaged by three screws (if three screws are fixed on the outer diameter of the encoder housing, the outer circle will be slightly deformed due to the screw up, not round, which affects the sealing performance), while the industrial housing does not need to be fixed with screws and sealed Adopt squeeze + O-ring for one-time sealing. Some users think that there is no dust and water vapor in the working environment, how can it be damaged? In fact, when the encoder is in use, there must be changes when it is turned on and off. Due to the temperature difference between thermal expansion and contraction, encoders with poor protection levels will produce "breathing" water vapor. Since the differential water vapor is sucked into the encoder, the optical components and circuits will be damaged due to the accumulation of time, thereby affecting the use or damaging the encoder. Usually it is not allowed to use for a period of time or the signal is unstable. However, some encoders have problems when used at higher temperatures. This is considered a temperature problem, but in fact they are a sealing problem.


3. Temperature class


The economic grade is generally only -10℃~60℃, and generally does not exceed 70℃. The industrial grade working temperature is generally -20℃~70℃, and the good one is -25℃~80℃. In fact, the temperature level reflects the selection level of internal parts. It should be known that the temperature of general civil electronic parts is mostly as high as 55 degrees or 60 degrees, and the price of advanced industrial parts above 70 degrees is often more than twice as expensive. The different levels are not only a temperature issue, but also the failure probability reflected in their use. The wide range is not only suitable for these extreme temperature ranges, but also has good resistance to temperature shock fluctuations. Some users think that the environment they use does not reach these temperature limits, but 55 degrees is enough. But they ignored the possible damage to the device caused by temperature shock fluctuations such as power-on and power-off, and the failure probability of internal chips.


4. Output signal and power


Most of the economical output is open-collector PNP or NPN, power and signal have no polarity protection and short-circuit protection, and the open-collector output is unilateral unbalanced. Anti-interference and poor signal transmission are not applicable under certain working conditions, especially engineering type. The industrial output is push-pull (PNP and NPN), or differentially driven balanced output, or other standard industrial signals. For example, SSI signals, some economic grades are also marked as SSI, but that SSI is not a standard industrial grade RS422, and it was found to be wrong when buying the connection; the industrial power supply is 10-30Vdc, and the long-distance voltage drop attenuation does not affect, so the signal line is often short-circuit protected . Many industrial field power supplies will be unstable in a short period of time. Wide power supply is very important to ensure that the encoder is not affected. Polar short-circuit protection can prevent the encoder from being damaged due to incorrect connections and accidents during engineering and maintenance.


5. Electromagnetic compatibility


The economical electromagnetic compatibility is not very high, and it is basically not specially designed for this purpose, while the industrial electromagnetic compatibility EMC generally has to reach level 2 or above (must have test standards and test certificates), including surges, fast pulse trains, static electricity, etc. Standard tests, these are related to the stable operation of the encoder in a complex electrical environment.


6.Internal parts:


The internal parts cannot be seen from the appearance and parameter table. Industrial-grade parts are often integrated and modular, and the circuit board is assembled and welded, and the three-proof treatment is adopted.


7. Test procedures and standards and costs:


For standard industrial encoders, due to the structural design and selection of parts, the cost of parts may be several times higher than that of economical encoders, and the test procedures and standards are also higher than that of economical encoders, so the cost of industrial Ethernet encoders is higher than that of economical encoders Much.


Various grades for special industrial purposes, such as explosion-proof grades, automotive electronics grades, high temperature grades (greater than 100 degrees), flood resistance grades, super heavy load grades, etc. , Are specially designed due to their different working conditions, so they will not be described in detail here.


Encoders of different levels may have large price differences, ranging from tens of yuan to several thousand yuan. Because encoders of different levels have different designs and usage goals, the cost of material selection and the cost of processing and testing vary greatly. Users can choose encoders according to their requirements, not just believing in imported or domestically produced products, or the promotion of a certain brand middleman. If there is no right choice, even if you buy a certain "imported" brand, there will be "so easy to break" or "not allowed" problems. Looking at samples from many companies, the products may be of different grades and prices vary greatly. But merchants often do not specify. Many import agents and even manufacturers, under imported brands, recommend low-end encoders to customers as standard industrial grades, which harms the interests of users and causes quality risks in use. At present, many Japanese and Korean encoders and some European encoders of different brands may only be of economic grade, especially some Japanese and Korean brands. Economic grades are mainly promoted in the country, users need to understand clearly




CANopen absolute encoder


CANopen绝对值编码器


Label

Copyright © Weihai idencoder electronic technology co.,ltd. All rights reserved Record number:Lu ICP No. 2021001739 Website construction:Henghui Technology