MicroE Systems' new Mercury™ 3000Si Dual Axis Averager for rotary applications is the latest member of the growing Mercury™ family of encoders. It is ideal for applications where the highest position accuracy is needed, and it can operate at very high speeds if necessary.

This new system is designed for precision rotary tables and actuators, and is particularly well-suited high for performance laser beam steering applications, such as laser marking, drilling, welding and cutting. It is also ideal for exotic rotary applications like long range, high magnification surveillance systems. More down to earth applications include the accurate centering of rotary scales during motion system setup.

The 3000Si Dual Axis Averager is also an economical solution for any XY stage. It allows engineers to conveniently cable two Mercury sensor heads to a single Interpolator module. Each axis can then be programmed to optimal resolution, up to 20 nm on each axis, using the SmartPrecision™ encoder software.

The system can also provide robustness in linear or rotary applications by using redundant sensors. By detecting any difference in real-time, faults can instantly be detected in motion systems.

Features at a Glance
Programmable interpolation to x1024
SPI format supported by leading DSP chip manufacturers
Bi-directional optical index repeatable to 1 LSB
Miniature sensor: 8.4mm tall
Instrument free alignment in under 30 seconds
Much faster than A-Quad-B output

The Dual Axis Averager is comprised of two Mercury™ sensor heads, a programmable SmartPrecision™ dual-interpolator/averager module
and a rotary glass scale. The system operates by eliminating rotational eccentricity errors through advanced signal-averaging and accuracy
optimization algorithms.

Signal processing and programmable interpolation to x1024 are performed within the unit's FPGA. Position data are digitized and then sent directly to the controller's DSP. This enables the motion system to operate at high speeds with unmatched position accuracy using averaged sensor feedback for closed-loop control.

The high-speed serial word interface allows operation at maximum resolution and rotational speed: up to 16.8M CPR (0.08 arc-sec) at 1300 RPM. This is many times faster than standard A-quad-B output. And the bi-directional optical index signal is repeatable to the encoder's resolution.

The SPI communications standard is supported by many DSP chip manufacturers. These include: TI, Motorola and Analog Devices.


Above is the serial word format. This format provides a robust connection that is ideal for encoder interfacing.

Like other Mercury™ encoders, the Mercury™ 3000Si Dual Axis Averager is miniaturized. It has the smallest high-performance sensor heads in the industry, just 8.4mm tall.

The Mercury™ 3000Si Dual Axis Averager also features LED indicators for instrument-free sensor alignment. Users can complete alignment procedures in under 30 seconds. Gain and phase correction are optimized automatically.

In addition to ultra high speed averaging, the Mercury™ Dual Axis Averager's SmartPrecision™ electronics and SmartPrecision™ software provide digital readouts and robust programmable features, including multiple index modes, output channel configurations and serial word interface settings.


SmartPrecision™ main setup screen for the Mercury™ 3000Si Dual Axis Averager.

Alarms for low signal alert are displayed and captured in an alarm history log. SmartPrecision™ software even displays encoder data in several ways: a Lissajous data plot of raw and corrected signals, signal strength vs. position, position vs. time and velocity vs. time.

Finally, the Mercury™ 3000Si Dual Axis Averager is ruggedized for high noise environments and delivers best-in-class noise immunity. SmartPrecision electronics are housed in a metal enclosure as are the sensor electronics, and all cabling is double shielded. Click here to view the data sheet

SmartPrecision™ Lissajous data plot for one channel. Display shows raw and corrected signal. Notice that the plots are virtually identical indicating the accuracy of the signal.