Installation manual

Danaher Motion Kollmorgen Appendix C

SERVOSTAR

S and SERVOSTAR

CD Series 107

APPENDIX C

Digital Incremental Encoder Types

The SERVOSTAR products include models designed for use with incremental

digital encoders. Encoders are available in different configurations from a

variety of manufacturers using different nomenclature and conventions, making

this topic somewhat confusing. Encoders can be as simple as having only A and

B output channels or as complex as 6 channels of outputs. The SERVOSTAR

pports many of these variants using the variable, MENCTYPE. The variable is

set according to the features of the encoder. This document explains the

different applications of the various MENCTYPEs. A basic understanding of

encoders is valuable for this discussion.

Encoder Basics: A Review

Encoders used with the SERVOSTAR provide incremental motor position

information via two channels, referred to as the A Channel and B Channel.

These channels output pulses for a unit of shaft motion. These pulses are

typically generated within the encoder, using an optical disk that is directly

connected to the motor shaft. The disk has etchings that either transmit or block

light passing through the disk. An optical transmitter and receiver are on either

side of the disk. The rotation of the disc (and motor shaft) interrupts light

transmission from source to receiver, creating the pulses. The interruptions on

the disk are called lines and result in the encoder ratings of lines-per-revolution

(LPR) or pulses-per-revolution (PPR). The two channels provide the same

information (pulses-per-unit of motion), but have a phase shift of 90º between

each other as shown in the figure below.