Corrected from:
9400 HighLine firmware version 12.00.18.00
9400 Servo PLC firmware version 06.00.18.00
Response of the new version:
If safely limited speed (SLS) is requested, the speed setpoint is decelerated to the limit value as expected using the SLSx parameters deceleration + S-ramp time.
Which products are affected?
9400 HighLine servo inverter with firmware version < 12.00.18.00
9400 Servo PLC servo inverter with firmware version < 06.00.18.00
What happens?
When activating a safely limited speed (SLSx) from an active profile generation, the speed setpoint is not decelerated to the limit value using the SLSx parameters deceleration + S-ramp time but the parameters of the last profile are used to decelerate the speed setpoint to the limit value. If this deceleration process takes much longer than with the expected SLSx parameters, the safety system may respond because the deceleration time has not been observed.
When does this problem occur?
The problem occurs if 'Override' is activated (POS_bEnableOverride=TRUE) and SLS is activated in an active positioning process. At the same time, the current setpoint speed is higher than the requested limitation.
Possible diagnostics?
Record the setpoint acceleration and the setpoint speed as output variables of the LS_Feedback using the internal oscilloscope of the 9400. From these values you can see the deceleration and jolt of the deceleration process after activation of SLS.
If the process differs depending on whether POS_bEnableOverride=TRUE or FALSE, the above-descrubed function restriction has occurred.
Short-term measures/recommendations?
Set POS_bEnableOverride to FALSE before activating SLS.
Evaluation:
The deceleration time to safely limited speed varies depending on the parameters of the profile generation influenced by requesting SLS.
If the deceleration time expected by the safety module is therefore not observed, STO is set. Plant availability is not given. An applicative remedy is possible.
