Is your machine experiencing issues with losing position during power outages or requiring time to perform Homing every time the machine is turned on? These problems directly impact unavoidable Production Downtime in the manufacturing process. These issues can be resolved by choosing an Absolute Encoder, which is a sensor superior to the general Rotary Encoder. The engineering team from SCMA is ready to provide advice and design measurement solutions that match your factory's needs. This article will take you through the working principles, maintenance, and detailed methods of selecting this type of equipment, so that you can apply it effectively to minimize errors in the production line.
What is an Absolute Encoder?
An Absolute Encoder is a type of encoder that provides a unique digital position value for every angle of the sensor's rotation. This device works by immediately sending out a signal indicating the actual position. This is different from Encoder Incremental type, which requires referencing a new starting point. This accurate position reading helps industrial control systems operate continuously without worrying about power surges or electrical system failures.
How Absolute Encoder Works
The operation of this sensor is distinguished by its ability to identify position accurately without relying on pulse counting like What is Encoder other types that require a reference point. The internal system is designed to read specific codes recorded on the disk, which makes this type of Rotary Encoder highly stable in all industrial environments.
Know the Real Position Immediately Upon Powering On
The device can recognize the real position of the shaft immediately upon power being supplied to the control system. This type of operation helps eliminate the need for a new Homing procedure even if the electrical system fails midway, allowing the production line to resume operation immediately without wasting time adjusting coordinates.
Use Specific Codes to Send Signals
The internal mechanism sends output signals as specific codes for each angular position. Popularly used codes include various formats such as Binary Code or Gray Code for data accuracy. Using these codes helps completely reduce errors in transmitting data to the main control system.
Multi-turn Rotation Memory
The Multi-turn structure can accurately remember the total number of rotation turns at all times. The device has a data recording circuit for rotation cycles even if the machine is turned off or the power goes out, making this type of Rotary Encoder ideal for applications involving long-distance movement.
Suitable for Applications Requiring High Precision
The device is used in machines that absolutely do not allow any positional deviation. The system can operate in conjunction with a PLC control set to enhance production efficiency in the factory. From the experience of the SCMA engineering team, selecting the correct sensor clearly helps reduce waste in the production process.
How many types of Absolute Encoder are there?
The classification of sensors is mainly based on the characteristics of their usage, so that users can choose a format that matches the movement of the machine. We can divide Absolute Rotary Encoder into 2 main types according to their ability to recognize position as follows
Absolute Single-turn Encoder (Single Turn Type)
This type of device can accurately indicate the position within a rotation range of just 1 turn (0 to 360 degrees). When the shaft completes one full turn and starts the next turn, the read position value will always reset back to zero. The sensor is suitable for angle measurement or short-distance movement tasks that do not exceed one rotation
Absolute Multi-turn Encoder (Multi-turn Type)
The main feature is the ability to accurately indicate the position within one turn while recording the total number of rotations. The internal mechanism has a special circuit for remembering the number of operating rotations, ensuring that data is not lost even if the machine is powered off. It meets the installation requirements for vertical movement shafts, heavy machinery, or lifting crane systems that require long-distance coordinate identification
Maintenance of Absolute Encoder
Proper maintenance is a key factor in preventing the loss of coordinate positions of the Rotary Encoder within the factory. A systematic maintenance approach helps extend the lifespan of the control device and effectively reduce machine stoppages.
Mechanical and Structural Inspection (Mechanical Maintenance)
Technicians must check the connection between the motor shaft and the sensor to ensure it is not loose or misaligned. Misalignment will cause the internal bearings to wear out quickly, resulting in measurement coordinate deviations. Rubber shock-absorbing pads should be added if installing the sensor structure in areas with high vibration.
Electrical and Signal Maintenance
The voltage level should always be maintained within the standard range to prevent errors in processing position codes. Signal cables must not have any damage, and the ground connection should be properly made to prevent electromagnetic interference. Regularly check the backup battery for Multi-turn models according to the specified schedule to prevent position data loss.
Environmental Control
Select the appropriate dust and water protection rating (IP Rating) according to the working environment conditions. Prevent oil, metal dust, or moisture from entering and obstructing the internal optical disk. Control the operating temperature not to exceed the factory specifications, and additional ventilation systems may be installed if necessary.
Cleaning and General Inspection
Clean external dirt with a dry, clean cloth. Do not directly spray high-pressure water onto the device. Avoid using highly corrosive chemical substances to clean sensor components. Users should check the operating status through the built-in diagnostic system to perform maintenance before the system malfunctions.
Application of Absolute Encoder in Industry
Currently, industrial factories use this type of sensor as a main device to convert rotational coordinates into specific digital codes. The ability to recognize positions even during power outages has made the Rotary Encoder a vital component of advanced production systems.
Automation Systems and PLC
Machines on the production line use sensors to provide precise position feedback. The device sends data to the PLC control system to quickly command the next operation. This coordinated operation perfectly reduces errors in assembling parts.
Robotic Arms and Industrial Robots
The control system requires precision in controlling the movement angles of each joint axis. This type of sensor responds to the movement of industrial robots instantly, allowing robotic arms to pick up or weld workpieces at designated points without any deviation.
CNC Machines
Metal cutting machines need to precisely control the movement of diamond-tipped cutting heads. The absolute encoder prevents the deviation of the workpiece table position even during power failures. From our case studies, the correct installation of the device has helped maintain the quality of CNC workpieces exceptionally well.
Conveyor and Crane Systems
Large overhead crane systems require accurate coordinates for safe operations. The sensor clearly identifies the movement distance of the pulley belt, effectively reducing accidents caused by movement beyond designated points in the factory area.
Advantages of Absolute Encoder
Investing in precise measurement technology is a decision that provides long-term value for business. This device has several outstanding features that elevate the capabilities of machines beyond general Rotary Encoders.
Reduce Production Downtime
The most important feature is the ability to resume operation immediately after a power interruption. Engineers do not need to spend time re-setting the initial coordinates for the entire machine system. The production process therefore continues uninterrupted, helping to maintain factory profits.
High Data Reliability
The unique encoding mechanism prevents errors from missed pulse signals. The raw data sent to the controller is 100% accurate. You can read the data What is an Absolute Encoder to learn more about encoding from global sources.
Resistant to Signal Interference
The digital protocol transmission is more stable than general analog signals. Large motor or machine wiring in the factory cannot interfere with coordinate value transmission. This reduces machine malfunctions caused by high electromagnetic wave environments.
Supports a Wide Range of Applications
It offers both shaft and hollow shaft options to fit motor shafts. Users can install it on almost all types of machines in the production line. The device is designed to be compact, saving space in control cabinet assembly.
Supports Modern Industrial Communication
Supports high-speed communication protocols such as PROFINET or EtherCAT, allowing the device to connect immediately to the network system of a smart factory. This promotes efficient data retrieval for predictive maintenance analysis.
How to Choose an Absolute Encoder
The selection of sensors should start with a detailed analysis of the machine's movement characteristics. We have summarized the important checklist for selecting this type of Rotary Encoder to help users make the right decision as follows
Type of Rotation (Single-turn or Multi-turn): For short rotation tasks not exceeding one revolution, Single-turn should be used. For long shaft tasks that require counting revolutions, choose the Multi-turn type for appropriateness
Accuracy (Resolution / Bits): Consider the accuracy of the Absolute Encoder based on the number of bits. The higher the number of bits, the more precisely the machine can detect positions
Signal Output Format (Output Protocol): Check the PLC control system to see which signal type it supports, such as Parallel, SSI, or industrial communication protocols
Size and Physical Characteristics (Mechanical Specifications): Choose the shaft diameter size that matches the motor, and select an appropriate IP Rating level for the environment
Power Supply: Check the voltage of the original control cabinet system to match the specifications of the new signal encoder
Differences Between Absolute Encoder and Incremental Encoder
Many users are confused between these two types of rotation sensors when designing control systems. The main difference between these two types of Rotary Encoders lies in the method of reading position values and stability when electrical faults occur
Position Recognition: The absolute type can immediately identify the actual position, while the Incremental type must search for a new reference point every time the machine is turned on
Signal Format: The Absolute Encoder sends data as a unique digital code, while the Incremental type sends data as pulse waves according to the rotation rhythm
Resistance to Interference: Digital codes are more stable against external electromagnetic interference than counting pulse wave rhythms
System Complexity: The absolute type has a more complex internal structure and higher price, but offers clearly superior accuracy
Application: The absolute type is suitable for robotics and CNC applications, while the Incremental type is suitable for general motor speed control tasks
Summary
The use of Absolute Encoder has revolutionized the industry with its ability to identify coordinate positions without error. This type of sensor exceeds the performance of traditional Rotary Encoder with the feature of remembering positions without needing to perform Homing again. If your factory is looking for ways to improve machinery, the team SCMA is ready to provide advice and present our services comprehensively.
Interested in purchasing or consulting via LINE Official: @SCMA
If you want to buy Absolute Encoder, you can buy it from SCMA today!
Selecting high-quality equipment is the first step toward achieving success in upgrading your factory's production efficiency. SCMA Co., Ltd., as a leader in industrial technology solutions, is ready to distribute Rotary Encoder from world-leading brands. Our engineering team is ready to provide integrated solution design services, so that you can truly use Absolute Encoder that meets your production needs.
Frequently Asked Questions
Can an Absolute Encoder replace an Incremental Encoder?
Yes, it can and performs better in terms of position recognition. Users just need to check the compatibility of the output signal with the original PLC system.
How often should the battery in the Multi-turn model be replaced?
Battery life depends on the device model as specified in the manufacturer's manual. Generally, it is recommended to check the status or replace the battery every 3 to 5 years.
Why is Gray Code better than Binary Code?
Gray Code changes only one bit position in each rotation step, greatly reducing the chance of data reading errors by the signal receiver.
What factors cause Rotary Encoder to fail the fastest?
The main issue is the installation of an off-center shaft, which damages the internal bearing. Allowing liquids and moisture to enter the device causes the electronic system to short circuit.
Does the SCMA team provide installation and calibration services for the equipment?
Our company provides comprehensive services from consultation to installation, along with a team of technicians to handle calibration work to maintain standards for customers in the long term.
