Methods -5 to -8: Homing using Precise pseudo absolute encoder

The Precise pseudo absolute encoder has an embedded pattern that can uniquely determine the absolute position of an axis.  To read this pattern, an axis only has to be moved a very short distance, typically just a few hundred encoder counts.  The procedures for homing an axis equipped with this encoder are defined in the following table.

Method#

Description

Use

Method -5 Moves axis in the positive direction and stops when a pattern is detected.  If the upper hard stop is encountered, moves axis in the negative direction and stops when a pattern is detected. These methods are normally employed on linear encoders   or very high resolution rotary encoders where unique patterns exist along the entire length of the axis.
Method -6 Moves axis in the negative direction and stops when a pattern is detected.  If the lower hard stop is encountered, moves axis in the positive direction and stops when a pattern is detected.
Method -7 Moves axis in the positive direction until the upper hard stop is encountered.  Then moves the axis in the negative direction and stops when the next pattern is detected. These methods are normally employed on rotary encoders where patterns are unique within a single turn of the encoder but the encoder rotates several revolutions for the entire travel of the axis.
Method -8 Moves axis in the negative direction until the lower hard stop is encountered.  Then moves the axis in the positive direction and stops when the next pattern is detected.