5-68
Motor, Mechanical Axis System, Measuring Systems
MPH-02, MPB-02, MPD-02
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
The controller is told via
S-0-0277, Position feedback 1 type
and
S-0-0115, Position feedback 2 type
which homing signals the connected
measuring system makes available.
During the homing procedure the controller automatically detects the
reference mark if its signal corresponds to the specification and the
reference mark is to be evaluated to establish the reference (see
"Establishing the Position Data Reference: Establishing Position Data
Reference for Relative Measuring Systems" in chapter "Drive Functions").
If a relative encoder has several reference marks over the travel distance,
a reference mark is to be identified by means of a home point switch at
the axis for establishing the position (see "Establishing the Position Data
Reference: Establishing Position Data Reference for Relative Measuring
Systems" in chapter "Drive Functions").
In the case of relative encoders with distance-coded reference marks,
several reference marks are distributed in equal distances over the entire
travel distance. There is a "shorter distance" and a "longer distance"
between one reference mark and the mark after the next. The controller is
informed of these two distances via
S-0-0165 Distance-coded reference
offset A
and
S-0-0166 Distance-coded reference offset B
.
501
502
503
1001
1001
1000
1000
DF0029v1.fh7
"shorter distance"
of the mark after the next reference mark
(S-0-0165, Distance-coded reference offset A)
"longer distance"
of the mark after the next reference mark
(S-0-0166, Distance-coded reference offset B)
reference marks
division periods (DP)
Fig. 5-80:
Reference mark distances in the case of a distance-coded linear
encoder with a distance difference of 1 DP
Note:
The values for "distance-coded reference offset
A" and
"distance-coded reference offset B" have to be indicated by
the manufacturer!
If the value of "distance-coded reference offset A" is not directly indicated
in the data sheet of the distance-coded encoder, the value can also be
determined by means of calculation if the travel distance for establishing
the absolute reference point is indicated in the data sheet of the encoder:
Reference Marks, Not Distance-
Coded
Distance-Coded Reference
Marks
Determining the "Distance-
Coded Reference Offset A"
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of
CMA/Flodyne/Hydradyne
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