2
Overview
16
Festo – EXCM-30/-40-...-PF-EN – 1603 – English
2.8
Measurement system
2.8.1
Basic concepts
Homing
During homing, the position of the axis zero point AZ is determined.
Stop point BZ (block zero point)
A fixed point in the origin of the selected coordinate system, which is travelled to in homing.
Movement to zero
After the stop point BZ is reached, the drive is travelled at a defined distance in order to reach the axis
zero point AZ.
Axis zero point AZ
It is shifted by a defined distance from the stop point BZ in the origin of the selected coordinate sys
tem. This distance is determined dependent on the size of the planar surface gantry in the direction of
the X- and Y-axis (
è
Tab. 2.1 Explanation of dimension reference points).
Project zero point (PZ)
A point to which the actual position and the absolute target positions refer. The project zero point is
shifted by a defined distance from the axis zero point AZ.
Software end positions SLN (Software Limit Negative)/SLP (Software Limit Positive)
Limit the effective stroke in the direction of the X- or Y-axis. If the target position of a positioning job is
outside the software end positions, the positioning job is not executed and a malfunction is reported.
The software end positions are shifted by a defined distance from the axis zero point AZ.
Working stroke
The distance of the software end positions in the direction of the X- or Y-axis. Maximum stroke by
which the planar surface gantry can travel in the corresponding direction.
Increments
The controller works in the range of the drive controller with encoder increments (EINC). In contrast,
so-called interface increments (SINC) are used at all user interfaces and in the field of internal data
management.
1 mm = 1000 SINC
1 EINC
L
19 μm
