VIONiC™ incremental encoder system with RELM20 linear scale
Features
- Digital output direct from the readhead
- Readhead size: 35 x 13.5 x 10 mm
- Resolutions to 2.5 nm*
- Speed up to 12 m/s
- Ultra-low Sub-Divisional Error (SDE): typically <±15 nm*
- Optical IN‑TRAC™ reference mark
- Dual limits
Benefits
- No separate interface required
- Advanced Diagnostic Tool for easy fault finding, challenging installations and servicing
- Very high accuracy combined with near zero thermal expansion
- High dirt immunity

What is VIONiC?
The VIONiC readhead combines Renishaw's market proven filtering optics and advanced interpolation into one digital incremental encoder with ultra-high accuracy.
The VIONiC encoder system offers a wide variety of speed and resolution configurations, and an expansive range of linear or rotary scale options. This makes it one of the most versatile encoder for high precision feedback. Designed with intuitive auto-calibration mode, VIONiC readheads are also easy to install.
What is new?
*The VIONiC encoder system is now available in resolutions down to 2.5 nm with enhanced SDE across the product range.
What is RELM20 scale?
RELM20 is a spar scale manufactured from ZeroMet™, a low expansion nickel/iron alloy, featuring 20 µm pitch incremental graduations.
It is comparable to fine pitch glass scales and offers a total accuracy (including slope and linearity) better than ±1.5 µm over a 1.5 m length. ZeroMet has a thermal expansion coefficient of 0.75 ±0.35 µm/m/°C at 20 °C.
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?
All purpose digital encoder system
VIONiC is the encoder of choice because it combines high speed interpolation with impressive metrology performance making it suitable for even the most demanding applications. A wide range of encoder configurations are available so that the user can optimise the speed and resolution of their system depending on their motion control requirements. Furthermore the VIONiC readhead works with both linear and rotary scales across a range of accuracies. The VIONiC encoder is quick and easy to calibrate, meaning it is suitable for volume production.
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.
Ease of handling
The RELM20 ZeroMet low thermal expansion scale has a much smaller cross section than typical glass scales and allows easier handling and installation without risk of breakage, making it ideal for the most demanding precision applications.
Optional Advanced Diagnostic Tool ADTi-100

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 | RELM20: high accuracy ZeroMet spar scale with mid reference mark Also available with end reference mark as RELE20 |
Readhead size (LxWxH) | 35 mm x 13.5 mm x 10 mm |
Scale pitch | 20 μm |
Coefficient of thermal expansion at 20 °C | 0.75 ±0.35 μm/m/°C |
Accuracy grade at 20 °C | Certified to ±1 μm per 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 1.5 m |
Maximum speed | Up to 12 m/s (See data sheet for details) |
Sub-Divisional Error (SDE) | Typically <±15 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 | 5 μm to 2.5 nm resolution (See data sheet for details) |
Electrical connection | 0.2 m, 0.5 m, 1 m, 1.5 m, 2 m and 3 m cable lengths with D-type connectors (9 and 15 pin), circular in-line connector (12 pin) or 14-way JST connector |
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 |
Sealing | IP40 |
* <±10 nm SDE can be achieved with optimised set-up. Please contact your local Renishaw representative for more details.
Refer to data sheets for full details.