Danfoss MCO 305 Design Manual page 163

MCO 305 Design Guide
__ Software Reference __
SYNCV
Summary Velocity synchronization with the master
Syntax SYNCV
NB!:
SYNCV should only be called up once since the synchronizing continues until the
next motion or stop command. All additional SYNCV commands cause the
synchronization to start over again from the beginning and this is not normally
intended, as you reset the actual synchronization error.
NB!:
Track and synchronization errors are not monitored in SYNCV mode, it is therefore
recommendable to use the hardware encoder monitor.
Description With SYNCV the velocity synchronization with the master is completed, for example
after an external disturbance. In doing so only the velocity is taken into considera-
tion and the controller does not attempt to recover the position.
V
Master velocity
Slave velocity
t
synchronization command
For synchronization and during the synchronization process neither the pre-set
velocity, VEL, nor the pre-set acceleration, ACC or DEC, are exceeded.
The parameters of the gear factors used for synchronization are: par. 33-10
Synchronizing Factor Master , par. 33-11 Synchronizing Factor Slave .
Furthermore, the speeds are not simply determined on the basis of the difference
between the current position minus the last position (master/slave), rather the
values are filtered according to the settings in par. 33-26 Velocity Filte r
(SYNCVFTIME). This means the filter for the slave is determined by the maximum
speed. In other words:
VELMAX * 5 corresponds to the encoder resolution for the filter table, where
VELMAX is the speed in qc/ms. (The formula is a result of the assumption that the
filter table for the encoder resolution was made with a maximum speed of 3000
RPM.)
During the transition from the speed controller to the position controller this is done
as smoothly as possible. In addition the new set position is defined in such a
manner that the following is true:
command_pos = actual_pos + error
old_error, cvel, avel are maintained.
Command Group SYN
Cross Index Parameters of the AXS group
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