Which products are affected?
ESP-SP-POS - Software Package Positioner V2.2
Wie sieht die Reaktion aus?
Immediately after the request for a quick stop (QSP), the motor control system switches from the profile generator to an internal module that brakes the drive using the specified quick stop ramp until the drive reaches standstill. The integrators in the profile generator for the setpoint and actual value are reset. Due to an internal signal conflict, the integrators were reset one cycle earlier than the isolation of the profile generator from the motor control system. There was then a brief setpoint step and only after this was the QSP deceleration initiated.
Possible diagnostics?
A setpoint step is to be seen in the speed setpoint at the motor control system immediately after the QSP request. The setpoint is set to zero for one cycle, then jumps back to the original value and is then reduced using the ramp set. The step in the setpoint results in a large jerk in the machine that is also audible in the majority of cases.
Short-term measures/recommendations?
None.
Evaluation:
Despite the problem, the drive speed is reliably braked to standstill using the QSP ramp. The step in the setpoint can only be detected in machines with low inertias. However depending on the application, the jerk produced can be inadmissible for the product or the machine. In these machines the problem can be often be detected during commissioning, or even during design.
