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Synchronizing controller
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MG.10.N4.02 - VLT is a registered Danfoss trademark
Function diagrams for speed synchronization
SyncStart
When closing the SyncStart contact (Terminal I1), the slave drive accelerates with minimum ramp time
to the speed of the master drive, taking the gear ratio into account. When I1 is opened, the slave drive
ramp or coast to stop. Stop behaviour is selected in parameter 725.
Figure 10: SyncStart with speed synchronization
Up/down factor
After the slave has been synchronized to the speed of the master by means of SyncStart (Terminal I1),
the gear ratio can be changed during operation. By means of Inputs 33 Speed+ / Up-factor, or
32 Speed- / Down-factor, the gear ratio can be changed by the value set in Parameter 744 (step width).
This change affects only the slave factor. For more sensitive adjustment of the gear ratio, the gear ratio
digits should be extended and a small step width should be selected.
If one of the two inputs is on longer than the time defined in Parameter 743 (step time), a further step
will be executed.
Example:
Gear ratio i = 22:43
If the step width is equal to 1, the first upward step will result in i = 22:44, which represents almost 3 %.
It would be better to set the ratio as i = 2200:4300. Then the upward step will result in i = 2200:4301,
which represents a change of approx. 0.03 %.