Renishaw To Show Resolute Absolute Encoder At MTEC

Renishaw will display its latest range of optical incremental encoders at MTEC, which will take place at the NEC, Birmingham from 27-28 April. Demonstrations will include a 1nm resolution version of Renishaw's Tonic incremental encoder, a magnetic chip encoder and an absolute optical encoder capable of 10 atoms resolution at 220mph and suitable for rotary and linear applications. Renishaw's Resolute absolute optical encoder system gives a 1nm resolution at 100 metres per second for both linear encoder and angle-encoder applications, yet still offers excellent dirt immunity.

Absolute position is acquired immediately at system switch-on, so the exact orientation of axis and motor commutation angle are known without the need for a reference (datum) return. Large set-up tolerances also enable easy installation and high reliability, while low jitter and SDE (sub-divisional error) meet the demands of high-precision stages. The Tonic range of incremental optical linear and rotary encoders now offers 1 and 2nm resolutions, a dual-output encoder interface and is also available with Renishaw's Dual Signal Interface (DSI).

The higher-resolution options comprise a standard Tonic readhead and new interfaces that apply high interpolation rates to achieve fine resolution and low jitter levels of just 0.51nm RMS. For applications requiring one or more operations to be synchronised with a motion axis, the new dual-output interface simultaneously provides analogue and digital signals. For high-accuracy angle encoding, the new Tonic DSI allows two readheads to be used to improve the accuracy and repeatability of a motion system by eliminating eccentricity, bearing wander and all 'odd' error harmonics.

Renishaw's AM4096 magnetic encoder IC offers 12-bit resolution (4096 steps per turn) and is capable of high-speed operation to 30,000rpm. It provides UVW outputs with 16 poles (eight-pole pairs), incremental, absolute, linear (potentiometer), tacho generator and sinusoidal outputs. Typical applications include commutation and high-speed motor control, position and velocity control, potentiometer replacement and optical-encoder replacement.

Renishaw Interface Available With Optical Encoders

Renishaw's Dual Signal Interface (DSI) is available with its Tonic range of incremental optical encoders. This offer is designed to bring higher accuracy to rotary axes and give customers a selectable reference mark position via the company's Propoz technology. Using two readheads on an angle encoder improves the accuracy and repeatability of the motion system by eliminating eccentricity, bearing wander and all odd error harmonics.

When used with Renishaw's REXM ring encoders, a total installed accuracy of better than +/-1arc/sec is achieved. The combined Tonic DSI system is said to make adding a second readhead easy, by taking care of the combination of incremental channels and reference mark processing. Renishaw's Propoz technology enables customers to select reference output position with the press of a button.

The Propoz output position is also angularly repeatable, regardless of bearing wander or power cycling. The Tonic DSI system can be used with Renishaw's RESM encoder rings in a range of standard diameters from 52 to 550mm (with larger diameters and custom sizes available on request), or with ultra-high-accuracy REXM rings for demanding precision rotary motion applications.