Siemens Drive-CliQ interface connects Renishaw Resolute encoder with Sinumerik and Sinamics

The operating principle of Renishaw's Resolute is analogous to an ultra-high speed digital camera, capturing images of the scale, enabling resolutions up to 1 nm to be achieved (32-bit on rotary) even at speeds up to 100 m/s (36,000 rpm on rotary). Advanced optics give the detection scheme intrinsic low Sub-Divisional Error (SDE) and very low noise (jitter), so users can benefit from lower velocity ripple and rock-solid positional stability. Resolute has sealed read heads and scales constructed from shatter-proof engineering materials. The non-contact format eliminates bearings, seals, couplings and guideways from the encoder design, thereby also eliminating the most common causes of shock/vibration-induced encoder failure. Even if the main seals on the axis fail, says Renishaw, Resolute readheads are sealed against ingress of oil and coolant. The non-contact format also helps improve system metrology. Resolute rotary encoders read a solid stainless steel scale that is locked to the axis shaft so the encoder does not suffer from the mechanical backlash, wind-up and coupling losses. Rotary scales include options with accuracy better than ±1 arc-second, low-inertia versions and sizes from 52 to 550 mm, with custom sizes also being available. Furthermore, the large through-hole allows the encoder to be mounted close to the point of interest without complicating the routing of services to payloads. Linear encoders, with both stainless steel and ZeroMet (low expansion nickel-iron alloy) scales share many of these advantages, mounting direct to the machine's structure or track guided. With precision-graduated single-track absolute code, linear scales include options with accuracy better than ±1 micron, or tape scales up to 10 m long. Position is calculated when the encoder receives a position request, so true-absolute position is determined every time. Each time the encoder receives a position request, Resolute determines position using one algorithm, then verifies that result using an independent position checking algorithm. Any errors can therefore be flagged to the controller before any servo control problem can develop. The scales are designed for easy installation, the readhead has large set-up tolerances and features an integral set-up LED which indicates, by colour, the signal strength being detected and flashes to warn of coding errors. This LED (repeated on the remote Drive-CliQ interface) provides simple diagnostics throughout the life of the encoder, without the need for specialised set-up boxes. Please note that the Resolute range is available with several other serial protocols, allowing connection to a variety of industry-standard drives and controllers.