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Laser encoder interfaces

Flexible laser interfaces for high resolution applications.

RPI30 parallel interface

The RPI30 accepts differential analogue 1 Vpp sine/cosine signals, interpolates by
4096 and provides an output in parallel format with up to 36-bits of position data being available. When used in combination with a double pass plane mirror interferometer system (PMI) (fundamental period of sinusoids is nominally 158 nm), this results in a Least Significant Bit (LSB) of 38.6 picometres at velocities of up to 2 m/sec.

Active lissajous correction can be enabled to compensate for DC offset and AC mismatch from the laser encoder to improve the Sub Divisional Error (SDE) to ±0.1 nm at low velocities.

RPI30 fast parallel interface

Features and benefits

  • High accuracy - low SDE contribution (±0.1 nm)
  • Active SDE correction - reducing errors in position measurement.
  • Position data - converts 1 Vpp analogue quadrature from RLE to position reading via parallel bus.
  • Active updating - DC offset and AC mismatch.
  • Ease of access: diagnostics connection for remote download and analysis.
  • Multi-axis solutions -Two axis output position and status over LVTTL (3.0 V) compatible bus.
  • Communication protocol - position data as 36-bit (two's complement word) and choice of LSB.
  • Live status - includes signal strength and error flags.

Specifications

Plane mirror system
Retroreflector system
Resolution38.6, 77.2, 154.4 or 308.8 pm 77.2, 154.4, 308.8 or 617.6 pm
Maximum velocity2 m/s 4 m/s
Output signal36-bit (two's compliment) 36-bit (two's compliment)
SDE* contribution (excluding RLE and without correction enabledPlane mirror - PMIRetroreflector - RRI
Velocity < 50 mm/s (PMI)
Velocity < 100 mm/s (RRI)
Signal Strength > 25%
< ±0.5 nm< ±1.0 nm
Velocity > 50 mm/s and < 2 m/s
Velocity > 100 mm/s and < 4 m/s
< ±2.0 nm< ±4.0 nm

*Non-linearity error
SDE* including RLE with correction enabledPlane mirror - PMIRetroreflector - RRI
Velocity < 50 mm/s (PMI)
Velocity < 100 mm/s (RRI)
Signal strength > 50%
< ±0.1 nm< ±0.2 nm

*Non-linearity error

RPI20 parallel interface

The RPI20 converts 1 Vpp analogue quadrature signals from an RLE laser interferometer encoder system to provide ultra-high resolution (4096x interpolation) positional feedback in a parallel word format.

RPI20 parallel interface with RoHS

Features and benefits

  • High resolution - up to 4096x interpolation of analogue quadrature signals
  • Multi-axis solutions - availability of seven axis capability from one bus.
  • Fast communications - with an input bandwidth of <6.5 MHz and a 36-bit parallel format output
  • High accuracy - low SDE contribution (±0.5 nm)

Optional dual axis VME host board to enable to the RPI20 to be used in VME system architectures.

Specifications

Resolution38.6 picometres (plane mirror system)
77.2 picometres (retroreflector system)
Maximum velocity1 m/s (plane mirror system)
2 m/s (retroreflector system)
Output signal36-bit parallel word

PMI

PMI

RRI

RRI

Velocity

<50 mm/s

<1 m/s

<100 mm/s

<2 m/s

SDE*

0.5 nm

2 nm

1 nm

4 nm

*Non-linearity error

RLI20-P laser interface - Panasonic

The RLI20-P interfaces a Renishaw laser encoder system with a Panasonic controller (MINAS A5-SERIES). Using the 1 Vpp analogue quadrature signals from the laser encoder the output is passed through a high speed interpolator before being output as incremental position reading in an RS485 format.

RLI20-P laser interface - Panasonic

Features and benefits

  • Panasonic capability - directly compatible with Panasonic controller (MINAS A5-SERIES)
  • Fast communications - high speed internal position update rate (100 MHz)
  • High accuracy - low SDE contribution (± 0.5 nm)

Specifications

Resolution1nm(plane mirror system)
2 nm(retroreflector system)
Maximum velocity1 m/s (plane mirror system)
2 m/s (retroreflector system)
Output signal2.5 Mbps RS485, compatible with Panasonic
MINAS A5 series controllers

PMI

PMI

RRI

RRI

Velocity

<50 mm/s

<1 m/s

<100 mm/s

<2 m/s

SDE*

0.5 nm

2 nm

1 nm

4 nm

*Non-linearity error

RSU10 USB interface

The RSU10 USB interface accepts a 1 Vpp sine / cosine signal from an RLE system, interpolates by x16,384 and provides a position reading via a USB port.

Using an RSU10 allows for measurement data to be compatible with Renishaw's established calibration software packages (LaserXL and QuickViewXL). This provides the ideal solution for users who need to view and analyse real-time dynamic measurement data.

A software development kit (SDK) with a maximum update rate of 20 Hz is supplied with each RSU10 which allows the development of function specific software.

RSU10 USB interface

Features and benefits

  • High resolution - x16,384 interpolation provides signal resolution to 9.64 picometres at velocity of 1 m/s
  • Flexible software - compatible with established calibration packages and offers the flexibility of Renishaw's software development kit.
  • Automated data capture - TPin trigger input facility allows data capture to commence on receipt of an externally generated signal.

Specifications

Resolution9.64 picometres (plane mirror system)
19.28 picometres (retroreflector system)
Maximum velocity1 m/s (plane mirror system)
2 m/s (retroreflector system)
Maximum update rate50 kHz (20 Hz max when using SDK)

PMI

PMI

RRI

RRI

Velocity

<50 mm/s

<1 m/s

<100 mm/s

<2 m/s

SDE*

3 nm

4 nm

6 nm

8 nm

*Non-linearity error

Product information