Quick stop (QSP), drive is not hold in standstill drift free
Which products are affected?
ECS axis module ECSxS (Speed & Torque) V1.0
What happens?
In spite of activated quickstop function (QSP) the drive, especially in case of hoists, cannot be hold in standstill completely drift free.
In case of hoists a slow drift can follow after enabling of the motor holding brake and pending QSP (for the time of the brake opening time parameterized under C0195).
When does the problem occur?
The bahaviour always occurs when the drive is supposed to be held in standstill via the QSP function.
In case of hoists a drift only occurs when during opening of the holding brake the disengagement time set in C0195 is longer than the actual opening time of the brake.
Possible diagnostics?
Drive diagnostics by GlobalDriveOscilloscope (GDO).
Short-term measures/recommendations?
The function block inputs 'Speed-MCTRL.PAdapt' and 'Speed-MCTRL.PosLim' have to be set to 100 % (= 16384).
Evaluation:
A drift only occurs when in standstill there are ambient influences on the drive. In case of horizontal drives there are generally only low ambient influences on the drive. In practice the described drift-behaviour is mainly relevant in case of hoist machines.
When the described measures are executed, the drift can slowly be prevented.
