Posted to News on 14th Dec 2023, 11:30
EnDat 3 extends HEIDENHAIN’s serial communications interface advantage
For over 25 years, with its world-leading EnDat protocol, HEIDENHAIN has been at the forefront of serial communications interface development. That advantage has now been extended with the development of EnDat 3, which presents an ideal solution for the digital manufacturing age, and beyond.
The HEIDENHAIN EnDat protocol first arrived in 1995 and was an extension of existing technology to meet the requirement for a fast and reliable interface for data transfer, in applications featuring absolute linear and rotary encoders. Then the key benefit of EnDat 2.1 was its ability to operate as a bi-directional interface.
In 2003 the next development, EnDat 2.2, delivered faster communication, with clock speeds up to 16 MHz allowing it to be used in closed loop systems an advantage over EnDat 2.1 which had a maximum clock speed of 2 Mhz. Advances in encoder technology allowed the absolute position values to be derived in the encoder, negating the need for the subsequent electronics to process serial and incremental signals.
Other enhancements included a single cable solution for servomotors, termed HMC 6, which could carry power and brake signals to the motor, as well as carrying encoder data back to the drive.
With EnDat 3 HEIDENHAIN continues to innovate, with the focus on digital manufacturing requirements. Key developments are faster data transfer, high transmission reliability, and improved diagnostics which have been combined with additional sensor data (from encoders or external devices) which are becoming pre-requisites for reliable system design.
All previous versions of EnDat communication have been point to point or master/slave. EnDat 3 now allows the possibility of bus topologies allowing multiple devices to be linked.
EnDat 3 also features enhanced functional safety features to SIL 3 (Safety Integrity Level), a common international standard to measure reliability and risk reduction. In addition, EnDat 3 can be used with the new HEIDENHAIN HMC 2 hybrid cable solution to create a single, standardised, cable from a drive to a servo motor to reduce system cabling and associated installation costs.
In brief, EnDat 3 is a universal protocol that can be applied to a large number of devices, primarily position encoders, with a wide range of measuring and scanning methods such as absolute and incremental, photoelectric, inductive or magnetic. Connectivity can be by BUS operation, hybrid cabling or sensor box technology with the ability to add additional internal or external sensors.
High performance is ensured by EnDat 3's short cycle times of 15 s with exceptionally low position-measurement jitter along with a high bandwidth of 12.5 Mbits/s at 100 m cable length (25 Mbits/s at 40 m). For the digital manufacturing era HEIDENHAIN has ensured that diagnostic performance is enhanced with electronic ID label for automatic system installation, online encoder diagnostics, condition monitoring and predictive maintenance improvements.
