Sin/Cos Incremental Encoder - Siemens SINAMICS S120 Commissioning Manual

A.6.2

SIN/COS incremental encoder

Description
Incremental encoders operate on the principle of optoelectronic scanning of dividing discs
with the transmitted-light method. The light source is a light emitting diode (LED). The light-
dark modulation generated as the encoder shaft rotates is picked up by photoelectronic
elements. With an appropriate arrangement of the line pattern on the dividing disk connected
to the shaft and the fixed aperture, the photoelectronic elements provide two trace signals A
and B at 90° to one another, as well as a reference signal R. The encoder electronics amplify
these signals and convert them to different output levels, sin/cos Vpp in this case.
Absolute position
After switching on the machine, the absolute dimensional reference for the machine zero
must be established with incremental encoders for positioning. Therefore, perform a homing
procedure. After homing, the absolute position is determined by adding up the individual
incremental signals.
Sin/Cos encoders are offered with and without SSI protocol.
Note
Using the SSI protocol
Information on the SSI protocol can be found in Chapter "SSI encoder (Page 423)".
Commissioning with Startdrive
Commissioning Manual, 11/2017, 6SL3097-4AA10-0BP1
A.6 Overview of measuring systems / encoders
Appendix
413