German Renishaw encoder Renishaw model Renishaw price

Renishaw encoders convert displacement into periodic electrical signals, which are then converted into counting pulses, with the number of pulses representing the magnitude of displacement. Based on operating principles, encoders can be classified into incremental and absolute types. Incremental encoders convert displacement into periodic electrical signals, which are then converted into counting pulses, using the pulse count to indicate displacement magnitude. An encoder is a device that converts angular or linear displacement into electrical signals. The former is called a code disk, and the latter a code scale. According to the readout method, encoders can be divided into contact and non-contact types. Contact types use brush outputs, where a brush contacting a conductive or insulating area indicates whether the code status is "1" or "0"; non-contact types use photosensitive or magnetosensitive elements as receiving sensors. When using photosensitive elements, transparent and opaque areas indicate whether the code status is "1" or "0".

Renishaw encoder device requirements

1. Requirements for CNC machine tools regarding detection elements and position detection devices (1) Requirements for CNC machine tools regarding detection elements: Detection elements are important components of detection devices, primarily used to detect displacement and speed and send feedback signals. The minimum displacement measurable by a displacement detection system is called resolution. Resolution depends not only on the detection element itself but also on the measurement circuit. The main requirements for detection elements in CNC machine tools are: (1) long service life, high reliability, and strong anti-interference capability; (2) meeting accuracy and speed requirements; (3) ease of use and maintenance, suitable for the machine tool operating environment; (4) low cost; (5) easy connection to computers. Different types of CNC machine tools have different requirements for the accuracy and speed of detection systems. Typically, large CNC machine tools prioritize speed requirements, while medium, small, and high-precision CNC machine tools prioritize accuracy requirements. When selecting the resolution and pulse equivalent of a measurement system, it is generally required to be one order of magnitude higher than the machining accuracy. (2) Requirements for CNC machine tools regarding position detection devices: Position detection devices are an important part of the servo system in CNC machine tools. Their function is to detect displacement and speed, send feedback signals, and form closed-loop or semi-closed-loop control. The machining accuracy of CNC machine tools is mainly determined by the accuracy of the detection system. Different types of CNC machine tools have different requirements for the accuracy of position detection elements and detection systems, as well as the maximum moving speed of the measured components. The highest level of detection elements and systems is: when the maximum moving speed of the measured component reaches 240m/min, the displacement detection resolution (minimum detectable displacement) can reach 1μm; for example, at 24m/min, it can reach 0.1μm. The maximum resolution can reach 0.01μm. CNC machine tools have the following requirements for position detection devices: (1) minimal influence from temperature and humidity, reliable operation, long-term accuracy retention, and strong anti-interference capability. (2) meeting accuracy and speed requirements within the movement range of the machine tool's executing components. (3) ease of use and maintenance, adapting to the machine tool working environment. (4) low cost. Introduction to spindle encoders 2. Classification of position detection devices: For different types of CNC machine tools, different detection methods can be adopted due to varying working conditions and detection requirements. (1) Incremental and absolute measurement: Incremental detection methods only measure displacement increments and use the number of digital pulses to represent the quantity of unit displacement (i.e., the minimum setting unit), issuing a measurement signal for every movement of one measurement unit. Its advantage is that the detection device is relatively simple, and any centering point can serve as the measurement starting point. However, in this system, displacement is read by accumulating measurement signals; once accumulation errors occur, all subsequent measurement results will be incorrect. Additionally, in the event of a fault (such as power loss), the correct position before the incident cannot be found; after troubleshooting, the worktable must be moved to the starting point to recount and find the correct position before the incident. Pulse encoders, resolvers, induction synchronizers, gratings, magnetic scales, laser interferometers, etc., are all incremental detection devices. Absolute measurement methods determine the absolute coordinate position value of the measured component in a specific absolute coordinate system and represent it in binary or decimal digital signals. Generally, these must be converted into pulse digital signals before being sent for comparison and display. With this method, the higher the resolution requirement, the more complex the structure. Such measurement devices include absolute pulse code disks, three-speed absolute code disks (also known as multi-turn absolute code disks), etc. (2) Digital and analog measurement: Digital detection quantifies the measured unit and represents it in digital form. The measurement signal is generally an electrical pulse, which can be directly sent to the CNC system for comparison and processing. Such detection devices include pulse encoders and gratings. Digital detection has the following 3 characteristics. (1) The measured quantity is converted into pulse counts, facilitating display and processing; (2) Measurement accuracy depends on the measurement unit and is basically independent of the range; however, cumulative code errors exist; (3) The detection device is relatively simple, and pulse signals have strong anti-interference capability. Analog detection represents the measured quantity using continuous variables, such as changes in voltage amplitude or phase. Precise analog detection over a large range imposes high technical requirements; in CNC machine tools, analog detection is mainly used for small-range measurements. Analog detection devices include tachogenerators, resolvers, induction synchronizers, and magnetic scales. The main characteristics of analog detection are as follows. (1) Direct detection of the measured quantity without quantization. (2) High-precision measurement can be achieved within a small range. (3) Capable of direct and indirect detection. Position detection devices installed on executing components (i.e., end components) to directly measure the linear or angular displacement of the end components are called direct measurement, which can form a closed-loop feed servo system,Measurement methods include linear gratings, linear induction synchronizers, magnetic scales, and laser interferometers to measure the linear displacement of executing components; since this detection method uses linear detection devices to measure the linear displacement of the machine tool, its advantage is that it directly reflects the linear displacement of the worktable. The disadvantage is that the detection device must be as long as the travel distance, which is a significant limitation for large machine tools. Position detection devices installed on transmission elements preceding the executing components or on the drive motor shaft measure angular displacement, which is then converted via the transmission ratio to obtain the linear displacement of the executing components; this is called indirect measurement and can form a semi-closed-loop servo feed system, such as mounting a pulse encoder on the motor shaft. Indirect measurement is reliable and convenient to use, with no length limitations; its disadvantage is that transmission chain errors from converting linear to rotary motion are added to the detection signal, thereby affecting measurement accuracy. Generally, compensation for machine tool transmission errors is required to improve positioning accuracy. In addition to the above position detection devices, servo systems often include speed detection elements to detect and adjust motor speed. The commonly used speed detection element is the tachogenerator.

Main functions of Renishaw encoders

It is a rotary sensor that converts rotational displacement into a series of digital pulse signals. These pulses can be used to control angular displacement. If the encoder is combined with a rack and pinion or a lead screw, it can also be used to measure linear displacement. After the encoder generates electrical signals, they are processed by numerical control devices CNC, programmable logic controllers PLC, control systems, etc. These sensors are mainly applied in the following areas: machine tools, material processing, motor feedback systems, and measurement and control equipment. In ELTRA encoders, the conversion of angular displacement adopts the principle of photoelectric scanning. The reading system is based on the rotation of a radial grating disk, which consists of alternating transparent and opaque windows. The entire system uses an infrared light source for vertical illumination, projecting the image on the disk onto the receiver surface. The receiver is covered with a grating layer, called a collimator, which has windows identical to those on the optical disk. The receiver's function is to sense light changes generated by the disk's rotation and convert these light changes into corresponding electrical changes. Generally, a rotary encoder can also obtain a speed signal, which is fed back to the frequency converter to adjust its output data. Fault phenomena: 1. When the rotary encoder fails (no output), the frequency converter cannot operate normally, running very slowly, and the frequency converter protection triggers shortly after, displaying "PG disconnected"... Joint action is required for proper function. To raise the electrical signal to a higher level and generate square wave pulses without interference, electronic circuits must be used for processing. Encoder pg wiring and parameters: The connection method between the vector frequency converter and the encoder pg must correspond to the encoder pg model. Generally, encoder pg models are divided into differential output, open-collector output, and push-pull output. The signal transmission method must consider the interface of the frequency converter pg card, so selecting an appropriate pg card model or setting reasonable parameters is essential. Encoders are generally divided into incremental and absolute types, with the biggest difference being: in incremental encoders, position is determined by counting pulses from a zero mark, whereas in absolute encoders, position is determined by reading the output code. Within one revolution, the output code reading for each position is unique; therefore, when power is disconnected, the absolute encoder does not lose track of the actual position. If power is restored, the position reading remains current and valid; unlike incremental encoders, there is no need to search for the zero mark. Encoder manufacturers produce comprehensive series, generally specialized, such as elevator-specific encoders, machine tool-specific encoders, and servo motor-specific encoders. Furthermore, encoders are intelligent, with various parallel interfaces for communication with other devices. An encoder is a device that converts angular or linear displacement into electrical signals. The former is called a code disk, and the latter a code scale. According to the readout method, encoders can be divided into contact and non-contact types. Contact types use brush outputs, where a brush contacting a conductive or insulating area indicates whether the code status is "1" or "0"; non-contact types use photosensitive or magnetosensitive elements as receiving sensors. When using photosensitive elements, transparent and opaque areas indicate whether the code status is "1" or "0". Based on operating principles, encoders can be classified into incremental and absolute types. Incremental encoders convert displacement into periodic electrical signals, which are then converted into counting pulses, using the pulse count to indicate displacement magnitude. Each position of an absolute encoder corresponds to a specific digital code, so its indication depends only on the start and end positions of the measurement, not on the intermediate process. Rotary incremental encoders output pulses during rotation, allowing position determination through counting equipment. When the encoder is stationary or power is lost, position is retained via the counting equipment's internal memory. Thus, after power loss, the encoder must not move; during pulse output upon power restoration, pulses must not be lost due to interference, otherwise, the zero point remembered by the counting equipment will shift. The magnitude of this shift is unknown until erroneous production results appear. The solution is to add a reference point; each time the encoder passes the reference point, the reference position corrects the memory position of the counting equipment. Before the reference point, position accuracy cannot be guaranteed. Therefore, in industrial control, methods such as finding the reference point before each operation or homing at startup are used. Such encoders are determined by the mechanical position of the code disk and are unaffected by power loss or interference. Absolute encoders determine the uniqueness of each position by mechanical position, requiring no memory, no reference point search, and no continuous counting. The position is read whenever needed. Thus,the anti-interference characteristics and data reliability of the encoder are significantly improved. Since absolute encoders are clearly superior to incremental encoders in positioning, they are increasingly used in industrial control positioning. Due to the high precision and large number of output bits of absolute encoders, if parallel output is still used, each bit's output signal must ensure excellent connection, and isolation is required for complex conditions. This results in many cable cores, causing inconvenience and reduced reliability. Therefore, for multi-bit output absolute encoders, serial or bus-type output is generally selected. The most common serial output for German-produced absolute encoders is SSI (Synchronous Serial Interface). Multi-turn absolute encoders: Encoder manufacturers apply the principle of clock gear mechanics. When the central code disk rotates, another set of code disks (or multiple sets of gears and code disks) is driven via gear transmission. Adding turn-count encoding to single-turn encoding expands the encoder's measurement range. Such absolute encoders are called multi-turn absolute encoders. They also determine encoding by mechanical position, with unique, non-repeating codes for each position, requiring no memory. Another advantage of multi-turn encoders is that the large measurement range often provides ample margin in actual use. Thus, during installation, there is no need to painstakingly find the zero point; a middle position can serve as the starting point, greatly simplifying installation and commissioning. Multi-turn absolute encoders have obvious advantages in length positioning and are increasingly used in industrial control positioning.

Renishaw encoder features

1) After power startup or internal/external power faults, the encoder does not require reference driving and can obtain the current accurate position once power is normal. Under interference from various harsh environments, the hollow encoder's original position test data remains stable and is not easily affected by interference. 2) The encoder can provide an incremental pulse code value for each axis position, especially in position control. Incremental encoders do not require counting, enabling direct high-speed internal reading and external output. Secondly, the hollow encoder reduces the cost of other additional input components by handling calculation tasks in the receiving device controller. For example, hollow encoders in multi-axis parallel-working industrial robots can achieve high-speed multi-axis parallel synchronization, as well as in various control fields requiring multi-axis synchronization. 3) Fast and reliable digital data transmission is currently one of the core elements of encoders. Due to their high-resolution characteristics, hollow encoders generally output digital signals directly without internal or external counting, so they are no longer affected by pulse reading and accumulation. They can respond at high speeds, and even in high-efficiency equipment, hollow encoders can achieve high-resolution outputs. 4) Furthermore, the encoder is a very flexible type, characterized mainly by compactness and ease of adjustment; position can generally be flexibly adjusted via spring plates. Hollow encoders can determine the rotation direction through A phase pulse signals and B phase output timing, thereby interpreting pulse signal values. Currently, hollow encoders are generally suitable for various application scenarios. 5) The clamping method and spring plate structure of this shaft encoder allow for easy position adjustment and absorption of load vibrations and shocks. Moreover, the hollow encoder outputs based on the shaft's rotational displacement during operation. Combined with the shaft via a coupler, it can directly detect rotational displacement. Typically, no origin reset is required at startup; under normal conditions, the rotation angle can be output in parallel as an absolute value.

Weidou Intelligent Technology specializes in selling German Renishaw rotary encoders, Renishaw incremental encoders, Renishaw absolute encoders, Renishaw optical encoders, Renishaw magnetic encoders, Renishaw shafted encoders, Renishaw hollow-shaft encoders, Renishaw contact brush encoders, Renishaw angle encoders, Renishaw linear encoders, Renishaw digital encoders, Renishaw draw-wire encoders, Renishaw position encoders, Renishaw hollow-bore encoders, Renishaw spindle encoders. All products are original imports from Germany. Customers are welcome to inquire and place orders.