Heidenhain ECA 4000 ring encoder

New design features of the ECA 4000 absolute ring encoder make it suitable for use in angular motion feedback, according to a Feb. 16 announcement released by Heidenhain Corp., Schaumburg, Ill. The next generation encoder builds on the success of its predecessor, the ERA 4000 incremental ring encoder that has been used for more than a decade in applications involving machine tool rotary tables, semiconductor wafer motion stages and robotics.

With the ability to provide a direct upgrade path for existing ERA 4000 applications as well as new applications, Heidenhain's new ECA 4000 absolute series ring encoder offers several benefits and features for angular motion feedback, the company reported.

The mechanically compatible ECA 4000 series comes in outer diameters ranging from 104mm to 560mm so that machine designers can pass cabling and other items through the center of the ring to streamline their design. Each ring size has a unique line count on the outer diameter and an associated accuracy. For the largest ring diameter, an accuracy of +/- 1.5 arc seconds is specified for the graduation, and each ring is capable of resolutions to sub 0.01 arc seconds, all with high RPM potential. The two-track graduation design is also highly resistant to contamination like dust, fingerprints and scratches.

Each ring has the well-known three-point centering method that allows the installer to locate the center of the drum to the center of the machine bearing within just a couple of minutes. A shim, or separately ordered plastic mounting tool, is used between the reader head and drum to make the appropriate scanning gap. After a quick check with the PWM 20, PWT 100 or other HEIDENHAIN diagnostic tool to verify signal quality, the whole encoder system is ready for feedback to the control via the high-speed serial interface Endat 2.2. The scanning units on the ECA 4000 series also come in Fanuc 05 and Mitsubishi 03-4 serial interfaces.