VIONiC™ incremental encoder system with RTLC20 linear scale
- Digital output direct from the readhead
- Readhead size: 35 x 13.5 x 10 mm
- Resolutions up 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
- No separate interface required
- Advanced Diagnostic Tool for easy fault finding, challenging installations and servicing
- Tape scale convenience and unrivalled ruggedness
- Carrier-type scale system for quick, easy installation and replacement of scale
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 RTLC20 scale?
RTLC20 is a low profile stainless steel tape scale featuring a 20 µm pitch and IN-TRAC customer selectable reference mark. It is accurate to ±5 µm/m and in lengths up to 10 metres (>10 metres on request). Two mounting options are available, both allow independent thermal expansion and tape scale convenience.
RTLC20 can be used with the revolutionary FASTRACK™ scale carrier system. This system allows a track to be laid quickly and easily with no need for fixing holes. A sacrificial spacer is removed and the tape scale is then fed into the track.
RTLC20-S is laid onto the substrate with self-adhesive backing tape. The self-adhesive is formulated in such a way that it allows for independent scale expansion to that of the substrate.
To complete the installation, both types of scale are clamped at one point to provide a datum position.
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.
Easily removable scale
The RTLC20 scale with FASTRACK carrier system is ideal for applications that need the machine to be broken down for transportation or require the scale to be installed/removed for transit. The scale can be pulled out of the guide rails and quickly replaced, even when access is limited, thus reducing machine downtime.
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
FASTRACK RTLC20: stainless steel tape scale with track mounting system
RTLC20-S: stainless steel tape scale with adhesive backing, for mounting directly to a substrate without FASTRACK guide rails
Readhead size (LxWxH)
35 mm x 13.5 mm x 10 mm
Coefficient of thermal expansion at 20 °C
10.1 ±0.2 μm/m/°C
Accuracy grade at 20 °C
IN-TRAC reference marks directly embedded into RTLC20 / RTLC20-S
Selector magnet(s) used to identify one or more reference marks
FASTRACK: 100 mm to 25 000 mm
RTLC20/RTLC20-S: 20 mm to 10 000 mm
(>10 000 mm on request)
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
5 μm to 2.5 nm resolution
(See data sheet for details)
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
5 V -5%/+10%, typically <200 mA fully terminated
100 m/s2 max at 55 Hz to 2 000 Hz
500 m/s2, 11 ms, ½ sine, 3 axes
0 °C to +70 °C
* <±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.
How it works
The VIONiC encoder 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 <±15 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.
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.