Renishaw is launching the Resolute FS absolute open-optical encoder as the latest addition to its existing functionally safe portfolio of products. Suitable for both linear and rotary axis applications, the Resolute FS provides all of the benefits of the standard Resolute true-absolute encoder but with FS (functional safety) certification.
The standard Resolute encoder is already designed to be inherently safe due to a built-in separate and independent position checking algorithm; this has enabled a seamless progression to full FS status and compliance with both the ISO 13849-1:2015 (Performance Level D) and IEC 61508:2010 (SIL2) standards. Full FS certification is required to guarantee the safe use of functions that include safe stops 1 and 2, safe operating stop (SOS) and safe limited speed (SLS) - all of which require functionally safe encoder feedback.
A practical example of the SLS function in action is when an interlocked machine guard is opened during normal operation. SLS will act to limit traverse speed to 0.1m/s and spindle rotation to 100rpm, thereby minimising the risk of personal injury. The Resolute FS is currently compatible with Siemens' DRIVE-CLiQ serial communications protocols, and other FS protocols are expected in the near-future.
Renishaw describes its Resolute encoder as the world's most advanced single-track true-absolute optical encoder system, delivering up to 1nm resolution, superior long-term reliability, instant operation after power-up without reference return, and high speed performance to 100m/s. The Resolute series is suitable for advanced motion control applications and enables smooth velocity control with cyclical errors of better than +/-40nm and excellent positional stability via jitter (noise) of <10nm RMS. The advantages of open-absolute encoders over enclosed designs include large through-hole rotary (angle) ring scales for easy design-in, low inertia and low-profile components, and the absence of wear associated with contacting parts. Furthermore, the Resolute encoder's easy installation as a result of generous set-up tolerances and an integral set-up LED, excellent dirt immunity and IP64 sealing, give outstanding performance even on the very long axes typical of heavy industrial applications.
Resolute FS encoder systems still offer customers the same outstanding performance of the Resolute series but with the added peace-of-mind that comes from compliance with the world's most stringent functional safety standards.
Follow the links to find out more about the Resolute FS and download a white paper: Safety first - the position determination and checking algorithms of the Resolute true-absolute optical encoder.