Siemens SIMATIC FM 453, Manual

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10-9
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
If the axis is operated as a rotary axis, the measuring system must be adjusted
in such a way that the measurement scale refers to the full circle (e.g. 0
_
and
360
_
).
S
Reference-measure input G90
In a full circle with 360
_
, reference-measure programming (G90) has the
peculiarity that there are always two options for reaching the set position.
0
_
315
_
225
_
180
_
135
_
90
_
45
_
270
_
Actual position Set position
0
_
315
_
225
_
180
_
135
_
90
_
45
_
Actual position
270
_
Set position
10 90
315
with direction R+ specified
/ N G1 G2 G3
X/t F M1 M2 M3 D
100
Option 1 Option 2
Fig. 10-3 Rotary Axis
Option 1:
With G90, the axis autonomously always takes the shortest path to reach
the set position of 45
_
, going via 0
_
to 315
_
.
Option 2:
The control signals (R+) or (R–) force the respective direction of the axis
– in this example 45
_
via 180
_
to 315
_
. (R+) or (R–) must already be
pending when positioning is activated (START).
Note
The direction (R+) or (R–) must be specified sufficiently in advance. A tra-
versing direction cannot be forced on a traversing block that is already ac-
tive, or on the traversing blocks (up to 4) that have already been calculated
in advance in G64 operation.
Operation with option 1 or option 2 is at the user’s discretion.
S
Incremental input G91
With incremental programming G91, the direction of rotation of the
rotary axis is defined by the sign of the position setpoint. Multiple rota-
tions can be programmed by setting a value > 360
_
as the position set-
point.
Axis as Rotary
Axis
Writing Traversing Programs