ELL18K Rotation Stage Evaluation Kit
Chapter 1: Introduction
Rev A April 2019
Page 1
Chapter 1 Introduction
The ELL18 Rotation Stage is part of the Thorlabs series of resonant piezo motor circuits and bare modules for
OEM applications. The resonant piezo design of these motors offers fast response times and precise
positioning, and are therefore particularly useful in scanning applications.
The high-speed digital signal processing (DSP) architecture supports a multi-drop serial communication
protocol, and a set of digital IO lines allows the user to control the movement and state manually by switching
the lines high (5V) or low (0V).
The stage is designed for closed loop applications requiring rotational positioning with 43.0 µrad of resolution.
The stage delivers a travel range of 360° continuous rotation, however the displayed position and requested
position commands are in the range 0 to 359.99°.
Homing is achieved using a combination of a reflecting optical sensor (IR) for coarse (0.5 to 1.0 mm) positioning,
then a magnetic sensor for fine (1.0 µm resolution) positioning. Using the ELLO software, the user can modify
the offset value to shift the homing position (up to a ¼ of turn). Furthermore, coarse homing can be selected in
a clockwise (CW) or counter clockwise (CCW) direction (fine homing is always performed in a CCW direction
to guarantee repeatability).
The module is powered via an external 5V power supply supplied in the kit.
A hand-held controller is supplied with the ELL18K/M evaluation kit to allow homing and manual jogging and/or
positioning. The unit can also be driven remotely via PC-based software, downloaded from
A compatible USB driver and source code are included in the software download package.
