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Data sheet: RLE system performance

Data sheet: RLE system performance
6Pages

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Renishaw’s RLE fibre optic laser encoder uses interferometry to provide high resolution, high linearity position feedback signals suitable for use in precision motion control applications. The RLE range offers a variety of laser units and detector heads to suit individual application requirements. To maximise application flexibility, all system components are fully compatible. Each RLE system comprises an RLU laser unit and one or two RLD detector heads. The RLU laser unit, containing the laser source and signal processing electronics, is available in either single or dual axis configuration, with a fibre optic umbilical that delivers laser light directly to the RLD detector head(s). Two RLU performance levels are available - RLU10 and RLU20. The RLU20 provides part per billion (ppb) laser frequency stability and is particularly suitable for vacuum and other controlled environment applications. The choice of laser unit determines the designation of the RLE system: RLE10 systems contain an RLU10 laser unit, RLE20 systems contain an RLU20 laser unit. The RLD detector head is the core of the optical measuring system, containing interferometer optics, a unique, multichannel fringe detection system and beam steering mechanisms. As detailed below, current RLDs provide three different interferometer configurations. Additionally, an RLD with no internal optics is available enabling the RLE system to be used with suitable external optics to measure linear displacement, angle and straightness. The RLD10 differential interferometer detector head measures the relative displacement between two plane mirror targets, one of which is a fixed position reference mirror (usually located on the tool). This ensures accurate positioning between process critical components and eliminates common mode errors. The RLD10 plane mirror (double pass) interferometer detector head contains measurement optics allowing the system to determine the relative displacement between a reference optic, housed within the RLD10 and a plane mirror target optic, positioned on the measurement axis. The RLD10 retroreflector (single pass) interferometer detector head contains measurement optics allowing the system to determine the relative displacement between the reference optic, housed within the RLD10 and a retroreflector target optic, positioned on the measurement axis. To maximise application flexibility, plane mirror and retroreflector interferometer detector heads are available with either 0º or 90º beam orientation. The heads can be mounted on either their top or bottom face, thereby providing an output beam with an orientation of 0º, 90º or 270º. The RLE directly produces digital quadrature output resolutions to 10 nanometres with differential and plane mirror (double pass) interferometers, and 20 nanometres when using a retroreflector (single pass) interferometer. Additionally, the RLE system provides low latency 1 Vpp sine / cosine signals which have periods of 158 nanometres and 316 nanometres when used with differential / plane mirror and retroreflector interferometers respectively. Optionally, either an RGE interpolator or RPI20 parallel interface may be used in conjunction with the analogue output of the RLE system to enhance output resolutions to 0.39 nanometres or 38.6 picometres respectively for differential / plane mirror (double pass) interferometer configurations, and 0.79 nanometres or 77.2 picometres for retroreflector (single pass) interferometer configurations. For non-vacuum applications, the RCU10 real-time quadrature compensation system may be used to provide real-time compensation for both refractive index variation and material expansion effects. This data sheet provides performance specification information for various RLE system configurati

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Differential interferometer system configuration for vacuum and controlled environment applications Plane mirror (double pass) RLE interferometer system configuration for X-Y applications Retroreflector (single pass) RLE interferometer system configuration for linear applications

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General outlines and dimensions Dimensions in mm (inches) Mounting holes The RLU can be mounted in any orientation, provided the surface is reasonably flat and free from vibration. Minimum cable and fibre bend radius is 25 mm Laser beam indicator For maximum flexibility RLD10 detector heads may be mounted on either top or bottom face, providing beam launch orientations of 0°, 90° and 270°. Fibre coupling Fixing: 4 off M3 x 0.5 x 35 mm or 5-40-UNC x 13/8 cap head screws on a 38 mm² pitch Overall dimensions of the detector head: Height: 31.5 (1.24) Length: 98 (3.86) Width: 50 (1.97) Laser...

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RLU output signals Digital incremental - Signal period RLD10-X3-DI differential interferometer mounting The RLD10-X3-DI detector head is designed to mount directly onto three pins (supplied with the detector head), located on the mounting surface. The mounting technique accommodates any differential expansion between the mounting surface and the detector head. The user is required to machine three M4 tapped holes for the pins, and, for vacuum applications, install an anti-reflection optical grade window for the laser beams. For alternative mounting requirements please contact a Renishaw...

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System operating parameters Laser type Output beam intensity During preheat this can rise to 600 µW Vacuum wavelength accuracy Laser frequency stability Output update rates User selectable update rate options Output formats Dual RS422 differential digital quadrature User selectable resolutions (see below) 1 Vpp sine / cosine Power supply requirements Operation at room temperature 20 ºC Normal atmospheric Laser beam diameter Cable length (standard) Detachable at the laser unit (and detector head in differential systems) Cable diameter Terminated with a 15-way D-type connector and 15-way high...

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Renishaw plc New Mills, Wotton-under-Edge, Gloucestershire GL12 8JR United Kingdom About Renishaw Renishaw worldwide Renishaw is an established world leader in engineering technologies, with a strong history of innovation in product development and manufacturing. Since its formation in 1973, the company has supplied leadingedge products that increase process productivity, improve product quality and deliver costeffective automation solutions. The People’s Republic of China A worldwide network of subsidiary companies and distributors provides exceptional service and support for its...

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Data sheet: RLE system performance 6Pages

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Data sheet: RLE system performance
6Pages