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Renishaw Launches Functional Safety Enclosed Encoder

Renishaw has launched functionally safe variants of its FORTiS enclosed encoder series. FORTiS FS is an enclosed linear absolute encoder system certified to functional safety standards – certain machinery safety functions, such as Safety Limited Speed (SLS), require the encoder position feedback to be functionally safe. Utilising an encoder system that is already rated for use in safety-related applications can make machine certification significantly easier.

Adopting these advanced machinery safety functions enables machine tool builders to make safer machines that are capable of higher functionality, reducing set-up times and machine downtime.

FORTiS FS encoders are compatible with the Siemens DRIVE-CLiQ and BiSS Safety serial communications protocols.

The innovative FORTiS enclosed linear absolute encoder series is designed for use in harsh environments such as machine tools.

The FORTiS encoder design is built upon industry-proven RESOLUTE encoder technology and provides high resistance to the ingress of liquids and solid debris contaminants. It features an extruded enclosure with longitudinally attached interlocking lip seals and sealed end caps. The readhead body is joined to a sealed optical unit by a blade, which travels through the DuraSeal lip seals along the length of the encoder.

Linear axis movement causes the readhead and optics to traverse the encoder’s absolute scale (which is fixed to the inside of the enclosure), without mechanical contact.

Customers can choose from two different extrusion profiles to suit their space requirements. The FORTiS-S linear encoder is the standard-sized encoder, available with measuring lengths from 140 mm to 3040 mm and is installed directly to a machined surface via flexure holes in the extrusion’s body.

The FORTiS-N encoder, available with measuring lengths from 70 mm to 2040 mm, features a narrower cross-section extrusion and a more compact readhead to enable installations in confined spaces. This model can be mounted directly to a machined surface via two end cap mounting holes or a mounting spar for greater rigidity.

Ian Eldred, Principal Mechanical Engineer at Renishaw, highlights a range of unique and ground-breaking design features, coupled with the introduction of newly released Functionally Safe (FS) variants:

“The new FORTiS enclosed absolute encoder range is the culmination of years of R&D effort at Renishaw. It delivers superior repeatability, reduced hysteresis and improved measurement performance due to an innovative non-contact mechanical design that doesn’t require a mechanical guidance carriage. Five years of accelerated life testing, under the harshest conditions, has enabled Renishaw to develop and refine the new advanced DuraSeal lip seals. These offer excellent resistance to wear and machine tool lubricants, superior sealing and ingress protection up to IP64 when combined with air purge.”

He continues, “FORTiS absolute encoders also feature integrated, specially-designed tuned mass dampers that deliver class-leading 30 g vibration resistance and push the limits of what enclosed encoders can endure. Installation of FORTiS encoders is quick and easy, which will help our customers save manufacturing and servicing time. Furthermore, with the growing industrial trend towards risk reduction for systems and processes, we were committed to providing Functional Safety variants for all FORTiS enclosed encoders. We are now delighted to offer FS certified products to the market just four months after launching the FORTiS range.”

FORTiS encoders feature a range of serial communications protocols including BiSS C, BiSS Safety, Siemens DRIVE-CLiQ, FANUC, Mitsubishi, and Panasonic. The encoder dimensions also ensure space and bolt-hole compatibility with a wide range of alternative current and legacy systems.

Unlike traditional installation methods, peripheral diagnostic equipment is not essential. Renishaw’s patented set-up LED and carefully designed installation accessories ensure intuitive and right-first-time installation that is substantially faster than more conventional systems, even in restricted locations.

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