1 Introduction 

The SCA94DD is a member of the Scancon eCODE Series of high resolution optical semi-absolute encoders. The eCODE encoders are communicating encoders that communicate over a standardized interface and therefore do not need any specialized hardware. All communication is handled by a powerful microprocessor which ensures low latency and short cycle time. The encoders in this series use a precision interpolating optical system which provides high resolution and accuracy. All data from the interpolating system are processed by the microprocessor insuring that all position and other data is accurate and recent within a few microseconds. The eCODE series implements several programmable functions including resolution, direction of rotation and preset/reset functions. It also implements diagnostic functions with error and status. Programmable functions can be programmed by the customer or be programmed by Scancon according to the customer’s needs. 

This version of the eCODE encoder is particularly made to be used in wind power generation on slow rotating direct drive generators. 

Due to the very high resolution it is able to measure rotor speed and position quickly and with high accuracy. 

The SCA94DD has the following features: 

 Profibus Interface for exchange of data with a master controller. 

 Quadrature and Index Outputs, A, B and Z and the complementary A-, B- and Z-. Quadrature outputs are protected by the Scancon TSM (Transient Suppression Module). 

 RS485 Interface for set-up. 

Measurement of Rotor Speed and Rotor Position. 

 Programmable Resolution of Quadrature Outputs 

 Programmable Direction of Rotation (Phase Sense). 

 Programmable Sample Time for Speed. This manual describes the implementation and use of the SCA94DD encoder.