Which products are affected?
ESP-SP-POS - Software Package Positioner V2.2
How is the reaction?
The referencing functions are realised in the previous version using the function block L_REF from LenzeElectricalShaft.lib. During referencing the motor control system must be switched between the profile generator and the referencing block in some referencing modes. In modes 6 and 7 this results in a setpoint step and thus to a high jerk at the machine.
Possible diagnostics?
An oscillogram of the speed setpoint at the motor control system shows a short step during referencing. At this moment the control system is switched from the profile generator to the referencing block. In modes 6 and 7 the profile generator is used to initially move to the reference switch, a switch to L_REF is then made during the movement and the drive positioned on a TP. During the switching, the speed set points in the two blocks are not identical. This causes the step in the setpoint. The resulting high jerk can also be heard as a 'crack' at the machine in the majority of cases.
Short-term measures/recommendation?
None. The setpoint steps cannot be avoided in modes 6 +7.
Evaluation:
The referencing is performed correctly. The step is only detectable in the machine 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.
