Laser encoder interfaces

Flexible laser interfaces for high resolution applications.

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.

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.


 Resolution 38.6 picometres (plane mirror system)
77.2 picometres (retroreflector system)
 Maximum velocity 1 m/s (plane mirror system)
2 m/s (retroreflector system)
 Output signal 36-bit parallel word


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

RPI20 parallel interface