Which products are affected?
L_MCProfileGenerator profile generator of the LenzeMotionControlVx.lib function library included in the Software Package Positioner as of V3.4. This profile generator is used in the template as of version 3.4.
What happens?
The drive decelerates unexpectedly long and does not follow the parameterised deceleration and S-ramp time.
When does the problem occur?
The behaviour only occurs in case of profiles with jerk limitation (S-ramp time > 0) in the 'S-profile-optimised' mode (wSProfileMode=1; in the Positioner template C3037 = 1) of the S-profile generation.
In every calculation cycle of the profile generator a speed, which would result from the set deceleration after expiry of the entire S-ramp time, is calculated (v=a_dec x t_S-ramp). The behaviour can only be observed if this speed is greater than 1.5x C0011 or 2x C1240 (max. traversing speed).
Possible diagnostics?
In case of an identical acceleration/deceleration of the profile, the speed setpoint profile must be symmetrical to an imagined ordinate in the profile middle. The behaviour described above is reflected in a considerably longer deceleration phase. Symmetry can be achieved by reducing the S-ramp time.
Short-term measures/recommendations?
The behaviour can be avoided if the profile parameters for the deceleration and S-ramp time are selected in such a way that the condition a_dec x t_S-ramp > 1.5x C0011 or 2x C1240 is not met.
Evaluation
The drive decelerates slower than expected. Thus, the complete positioning lasts too long. The positioning target is approached correctly without reversing. When the same profile parameters are used the behaviour can always be observed.
