7.13 Switch-On and Switch-Off Behavior
Behavior of “holding brake” function
Drives with an enabled holding brake function have a special timing for switching on and off
the output stage. Events that remove the DRV.ACTIVE signal trigger the holding brake to
apply. As with all electronic circuits, the general rule applies that there is a possibility of the
internal holding brake module failing.
Functional safety, for example with hanging load (vertical axes), requires an additional mech-
anical brake which must be safely operated, for example by a safety control.
If velocity drops below threshold
CS.VTHRESH
or timeout occurs during a stop procedure,
the brake is applied. Set parameter MOTOR.BRAKEIMM to 1 with vertical axes, to apply the
motor holding brake immediately after faults or Hardware Disable.
Safety function STO
With the functional safe function STO, the drive can be secured on standstill using its internal
electronics so that even when power is being supplied, the drive shaft is protected against
unintentional restart. The chapter “Safe Torque Off (STO)” describes how to use the STO
function (
7.13.1 Switch-on behavior in standard operation
The diagram below illustrates the correct functional sequence for switching the drive on.
AKD-N Installation | 7 Technical description and data
Kollmorgen | kdn.kollmorgen.com | February 2018
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