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Synchronizing controller
40
MG.10.N4.02 - VLT is a registered Danfoss trademark
Hold function
The Hold function operates the slave drive in closed loop speed control at a speed independent of the
master. With Parameter 726 (Hold function) you can choose whether the slave is to run at a fixed
speed set in Parameter 727 or whether it is to maintain current speed. For the duration of the Hold
signal, the speed of the master is no longer taken into account; the master can even stop without this
having any effect on the slave drive. While the Hold function is activated you can change the speed
with inputs 32 and 33. The speed is changing according to the settings in parameter 728(Delta hold
speed) and parameter 744(Step width).
Figure 12: Hold speed
Gear changing
During synchronous operation, it is possible to switch between 4 fixed gear ratios, set in parameters
737 - 739. The fixed gear ratios are selected at terminals 16 and 17:
Input 16
Input 17
Gear ratio #
0 0
0
0 1
1
1 0
2
1 1
3
To activate the new ratio you must activate input I2. The newly set gear ratio is attained with the
minimum possible ramp.