6-34
Drive Control
6.3
Axis Control (Open-Loop Operation)
Brief Description
Recommissioning of Synchronous Motors with
Incremental Measuring System
At the first drive enable after switching on or after the measuring system
has been reinitialized, the drive automatically determines the commutation
offset. The value is stored in P-0-0521 and refers to the current position of
the axis.
If an incremental measuring system now requires the function "drive-
controlled homing procedure" to be started, the value of P-0-0521 is
converted to the position of the home point when the home point is
passed. This converted value now is compared to the optimum
commutation offset value stored in P-0-0508 at the initial commissioning.
If the comparison results in "plausibility", the value of P-0-0508 is
accepted as effective commutation offset value in P-0-0521 ("fine
adjustment" of the commutation offset). If there is no plausibility the value
in P-0-0508 is probably incorrect (e.g. inverted value in the case of
several axes etc.). The F2032 Plausibility error during commutation
fine adjust error message is output, the drive switches off.
Note:
If the fine adjustment of the commutation offset is not desired,
it can be deactivated via P-0-0508 = 0 or P-0-3008 = 0 (can be
written in communication phase "P2"). This causes the
automatically determined value to remain effective!
Manually Optimizing the Commutation Offset Value
The automatically determined value for the commutation offset is stored
in parameter P-0-0521, Effective commutation offset. When the initial
commissioning mode is active (respective bit in P-0-0522) the value of
P-0-0521 can be manually optimized. The optimization should be carried
out using a force measurement device!
=
P
-
- 0
0521(manua
lly)
Fig. 6-22:
Range of values for optimizing the commutation offset
Property damage caused by errors when
controlling motors and moving parts!
⇒ Before optimizing the commutation offset, move the
axis to a noncritical position!
CAUTION
In operation without encoder (open-loop operation) the velocity control
loop is not closed in the drive, but the drive is operated in a velocity-
controlled way (without feedback) via open-loop U/f control.
Note:
The method of open-loop/closed-loop motor control can be
selected via bit
current controller
See also section "Motor Control" in the same chapter
MPH-02, MPB-02, MPD-02
P
-
- 0
0521(autom
atically
14
of parameter P-0-0045, Control word of
.
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
±
determined
)
256