Skip navigation

VIONiCplus™ incremental encoder system with RSLM linear scale


  • Digital output direct from the readhead
  • Readhead size: 35 x 13.5 x 10 mm
  • Resolutions to 2.5 nm
  • Speed to 3.63 m/s
  • Ultra-low Sub-Divisional Error (SDE): typically <±10 nm
  • Optical IN‑TRAC™ reference mark
  • Dual limits


  • No separate interface required
  • Advanced Diagnostic Tool for easy fault finding, challenging installations and servicing
  • High accuracy spar scale
  • High dirt immunity
Transparent patch for website banners

What is VIONiCplus?

VIONiCplus integrates Renishaw's filtering optics design and interpolation technology to create a high performance, super-compact, digital all-in-one incremental open optical encoder. It offers resolutions down to 2.5 nm and a wide range of configurations to optimise the speed of your motion control system. VIONiCplus systems are quick and simple to install with wide set-up tolerances and automatic calibration. VIONiCplus implements our latest interpolation algorithms and signal processing techniques to achieve a typical Sub-Divisional Error of <±10 nm. This is world-leading performance from a 20 µm pitch incremental encoder system.

The Advanced Diagnostic Tool aids fault finding and servicing, and assists optimisation of system setup for challenging installations.

What is RSLM scale?

RSLM is a stainless steel spar scale featuring 20 µm pitch incremental graduations and a variety of IN-TRAC optical reference mark options, including regularly spaced for customer selection or single reference at the centre or the end of the scale.
It is comparable to fine pitch glass scales and offers a total accuracy (including slope and linearity) better than ±4 µm over a 5 m length. It can also be coiled for simple storage and handling yet once uncoiled behaves as a spar scale.
System designers can choose between specially formulated adhesive tape or mechanical clips to suit mounting requirements. Both mounting methods allow for independent thermal expansion to that of the substrate.

Why choose this encoder system?

World-leading performance from a 20 µm pitch incremental encoder system

VIONiCplus, using our latest interpolation algorithms and signal processing techniques, can achieve a Sub-Divisional Error (SDE) as low as ±10 nm. Low SDE directly equates to low velocity ripple which is important for constant velocity applications, such as scanning measurement systems. VIONiCplus' intelligent interpolation chip can achieve 8 000 x interpolation which equates to 2.5 nm resolution directly out of the readhead. This system is used when precision and repeatability is of paramount importance.

Easy fault finding and servicing

The Advanced Diagnostic Tool is available for comprehensive encoder feedback . This can be used for challenging installlations and fault finding. It provides:

  • Remote calibration functions
  • Signal optimisation over axis length
  • Readhead pitch indication
  • Limit and reference mark indicators
  • DRO and lissajous outputs.

Combines rugged reliability with higher accuracy

The VIONiCplus RSLM system offers the convenience, ruggedness and ease of use of a tape scale yet offers a higher accuracy than glass scales making it ideal for long length, high performance axes.

Optional Advanced Diagnostic Tool ADTi-100

VIONiC Advanced Diagnostic Tool

The VIONiC encoder system is compatible with the Advanced Diagnostic Tool ADTi-100 and ADT View software. They provide comprehensive real-time encoder data feedback to aid more challenging installations and diagnostics. The intuitive software interface can be used for:

  • Remote calibration
  • Signal optimisation over the entire axis length
  • Readhead pitch indication
  • Limit and reference mark indication
  • Digital readout of encoder position (relative to the scale)
  • Monitoring the velocity against time graph
  • Exporting and saving data

Technical specifications

Measuring standard

RSLM: high accuracy stainless steel spar scale

Also available with end reference mark as RSLE, and with selectable reference mark as RSLC

Readhead size (LxWxH)

35 mm x 13.5 mm x 10 mm

Scale pitch

20 μm

Thermal expansion coefficient at 20 °C

10.1 ±0.2 μm/m/°C

Accuracy grade at 20 °C

±1.5 μm up to 1 m, ±2.25 μm up to 2 m, ±3 μm up to 3 m, ±4 μm up to 5 m, calibration traceable to International Standards

Reference mark

IN-TRAC  reference mark

Various reference mark position options, see data sheet for details

Limit switches

Dual limits

Scale length

20 mm to 5 000 mm

Maximum speed

Up to 3.63 m/s

(See data sheet for details)

Sub-Divisional Error (SDE)

Typically <±10 nm

Dynamic signal control

Real time signal conditioning including Auto Gain Control (AGC), Auto Balance Control (ABC) and Auto Offset Control (AOC) for optimised performance across a range of operating conditions

Incremental signals

0.1 μm to 2.5 nm resolution

(See data sheet for details)

Electrical connection

0.5 m, 1 m, 1.5 m, 2 m and 3 m cable lengths with D-type connectors (9 and 15 pin) or circular in-line connector (12 pin)

Power supply

5 V -5%/+10%, typically <200 mA fully terminated

Vibration (operating)

100 m/s2 max @ 55 Hz to 2 000 Hz

Shock (non-operating)

500 m/s2, 11 ms, ½ sine, 3 axes

Operating temperature (system)

0 °C to +70 °C



Refer to data sheets for full details.



Data sheets

Technical drawings

How it works

VIONiCplus features the third generation of Renishaw's unique filtering optics that average the contributions from many scale periods and effectively filter out non-periodic features such as dirt. The nominally square-wave scale pattern is also filtered to leave a pure sinusoidal fringe field at the detector. Here, a multiple finger structure is employed, fine enough to produce photocurrents in the form of four symmetrically phased signals. These are combined to remove DC components and produce sine and cosine signal outputs with high spectral purity and low offset while maintaining bandwidth to beyond 500 kHz.

Fully integrated advanced dynamic signal conditioning, Auto Gain , Auto Balance and Auto Offset Controls combine to ensure ultra-low Sub-Divisional Error (SDE) of typically <±10 nm.

This evolution of filtering optics, combined with carefully-selected electronics, provide incremental signals with wide bandwidth achieving a maximum speed of 12 m/s with the lowest positional jitter (noise) of any encoder in its class. Interpolation is within the readhead, with fine resolution versions being further augmented by additional noise-reducing electronics to achieve jitter of just 1.6 nm RMS.

TONiC™ optical scheme with annotations

The IN-TRAC reference mark is fully-integrated in the incremental scale and is detected by a split photodetector within the readhead. As the diagram shows, the reference mark split detector is embedded directly into the centre of the incremental channel linear photodiode array ensuring greater immunity from yaw-dephasing. This unique arrangement also benefits from an automatic calibration routine that electronically phases the reference mark and optimises the incremental signals.