EnDat 3

HEIDENHAIN CORPORATION announces EnDat 3, a new version of its popular absolute position encoder interface. The new EnDat 3 interface has all the benefits of previous versions, but is even faster and more robust, with simplified functional safety features.

EnDat 3 uses a 200 kHz clock frequency, compared to the 16 kHz of previous versions, and has doubled its supported bandwidth, from 12.5 to a 25 Mb/s. This means that data can be transferred much more quickly. 

HEIDENHAIN has simplified functional safety aspects of the interface, and EnDat 3 now leverages the industry standard for functional safety: black channel. This makes implementation much easier for OEMs.

Milton Willis, Machine Tool Product Specialist at HEIDENHAIN, said: “We’ve listened to feedback from machine tool manufacturers and their end users, as well as OEMs, and have responded by making EnDat 3 faster, more robust, and more fully-featured than any competitive product.”

The EnDat 3 interface detects its absolute position, rather than just its position relative to a reference. This is a big advantage when a machine starts up, as it does not require any machine movement to establish its position – which can be extremely time-consuming for large machines. EnDat 3, therefore, enables faster startup, which means more throughput.

The new encoder interface has reduced cabling requirements compared to the previous version, going down to a two or four-wire setup as opposed to the eight wires previously needed. This reduces cabling requirements and hence cost, which is a significant benefit in the machine tool and robotics sector. For robotics applications, the EnDat 3 also offers bus operation, which allows manufacturers to daisy-chain encoders together, to reduce cabling and therefore reduce costs, as well as to simplify design and manufacturing.

EnDat 3 has increased memory and storage capacity and offers the ability to password-protect information that is stored in the encoder. For example, this could be specific code or machine information to which the company or manager might not want to allow full access for operators.

The new interface supports an increased number of temperature sensors, to monitor temperatures anywhere, from a robotics arm to inside a cabinet. It has also added support for multi-dimensional encoders, which enables easier installation and simplifies the downstream calculation that’s involved with using multiple reader heads on a single cable.

Like all the versions of EnDat, the new EnDat 3 is bi-directional, so it can support monitoring and diagnostics. This means it can be used for preventative maintenance, for example alerting the CNC when a fault is detected.

The first commercial version of the interface, EnDat 2.1, was created in 1995. At that time, most encoders used analog or digital incremental interfaces. EnDat 2.1 used an RS-485 output signal, which is more robust and less susceptible to noise.