Variety of interfaces ensures compatibility
The connection to all common motor controls enables wide-ranging electronic compatibility, e.g. via the serial interfaces EnDat, DRIVE-CLiQ, Fanuc Serial Interface, Mitsubishi High Speed Interface, and many more. Thanks to the elimination of analog signals, these fully serial interfaces offer potential savings in terms of the cabling technology required between the position encoder and the subsequent electronics. The position values are digitalized in the encoder and then transferred to the subsequent electronics. This minimizes potentially negative influences on the quality of the position information and its transmission that can arise when sinusoidal signals are used, and it increases the attainable position resolution compared with that of incremental interfaces using TTL or HTL output signals. Furthermore, a serial interface enables transmission of the "electronic ID label" information for the commissioning of the encoder and the drive. It also transmits additional data such as the winding temperature of the motor and diagnostic data. During operation, the EnDat 2.2 interface makes it possible to quickly and reliably provide information about the functional condition of the position encoder as part of regular maintenance or in the event of a malfunction. Maintenance measures can then be derived based on this information. Because functional safety is becoming increasingly important many encoders are also available in versions for safety-related applications. In addition to precise position measurement and reliable data transmission to the machine control, these encoders also have mechanically safe connections and feature the necessary mechanical fault exclusion. They thus provide all prerequisites to achieve classification SIL 2 in conjunction with a safe control system, or even SIL 3 in particularly critical applications.
Scalability of encoders for rotary axes
A demo unit equipped with different angle encoders on an ETEL torque motor illustrates the influence of the measuring principle on the dynamics and accuracy of rotary axes. It also shows the system architecture for digital temperature monitoring of the torque motor. For applications with special requirements, e.g. in machine tools, robotics, medical technology, and astronomy, selecting the right encoder is decisive for realizing the desired properties of a rotary axis:
- The new RCN 2001 optical angle encoders with integral bearing and integrated stator coupling now offer even greater system accuracy and a higher maximum rotational speed.
- The new generation of modular, optical ERA angle encoders is now also equipped with the HEIDENHAIN HSP 1.0 signal processing ASIC. The HSP 1.0 almost completely compensates fluctuations in signal amplitude caused by contamination on the scale drum.
- AMO will present its WMKA modular scale-tape solution for especially large diameters. These encoders feature EnDat and DRIVE CLiQ interfaces and are ideal for safety-related applications.