Heidenhain EnDat3 Absolute Encoder Offers Higher Data Rate

August 24, 2023 by Shawn Dietrich

Heidenhain has announced an updated version of its popular encoder interface to support faster data transmission along with integrated safety.

Heidenhain offers several different types of encoder technology; including linear, angle, and rotary designs. The company also manufactures a line of camera systems, length gauges, digital readouts, signal converters, and testing devices. Considering the breadth of its product portfolio, it comes as no surprise Heidenhain continues to introduce technologies perfect for high-accuracy machine tooling, as well as manufacturing and processing industries. Recently Heidenhain released a new version of their EnDat interface, the EnDat 3.


EnDat Interface

Heidenhain manufactures encoders, but they also created a digital bi-directional interface for their encoders. This interface allows OEMs and machine tool builders that use a Heidenhain encoder to monitor incremental or absolute positional values while updating variables that are stored in the encoder. There are two previous versions of EnDat; 2.1 and 2.2, with 3.0 being the most recent release.


Heidenhain's new encoder

The EnDat 3 encoder, is a new product by Heidenhain. Image used courtesy of Heidenhain


Features of the EnDat 3.0

The EnDat 3.0 interface has all the features of the previous release with added safety and faster communications. EnDat 2.2 uses a clock frequency of 16 kHz, while the new EnDat 3.0 version's clock speed is 200 kHz. Heidenhain has also increased the communication bandwidth from 12.5 Mb/s to 25 Mb/s. These additions allow for not only more data to be transferred but also at a much higher speed.


Light and dark encoder pattern on the rotary disk

Encoders have tiny incremental light and dark patterns inside, requiring a high-speed counter to track motion. Image courtesy of Adobe Stock


The latest version of EnDat utilizes the industry standard for functional safety, which is sometimes referred to as the black channel. This reference refers to a specific channel of data that runs alongside standard data but is unseen to users who don’t have the correct permissions or authentications. By following this standard, Heidenhain can safely transmit bi-directional data and safety data on the same interface.

When equipment powers on servo motor position is typically unknown and all the servo motors must be driven to a reference position. Depending on the number of servo motors and their function this process could take some time, which results in a loss of production time. With EnDat 3.0 encoders the interface is able to detect their absolute position instead of a position relative to a reference position, allowing for a faster start-up and higher throughput.


EnDat 3 encoder features

Features of the new EnDat 3 by Heidenhain. Image courtesy of Heidenhain


Cable quantity has also been reduced in the EnDat 3.0 version. In previous versions, cables required up to eight wires, but in the EnDat 3.0 version, only two or four wires are required. By reducing the number of conductors required in the cable, the device is cheaper to manufacture, is more flexible, is lighter, and can be installed in tighter locations. EnDat 3 includes bus operation, which facilitates daisy-chaining encoders.

Storing data on the encoder is a great way to reduce errors in control systems concerning calculating servo motor position. The EnDat 3 has increased the memory size capacity and even added a method for password-protecting data.


Encoder Diagnostics

Monitoring temperature is an important diagnostic tool when it comes to motors and the EnDat 3 interface has increased the number of allowable temperature sensors. EnDat 3 can monitor temperature from the encoder all the way back to the electrical cabinet. Heidenhain has even added support for multi-dimensional encoders.

The recently released interface has many features along with still being bi-directional so your systems can monitor position while also monitoring diagnostics, which is very important when using preventative maintenance tools.