Corrected from:
- i700 servo inverter V01.09.03.10964
Response of the new version:
When activating safe torque off (STO), the actual speed value is set to zero in the i700 servo inverter.
When the controller is inhibited, the speed setpoint is set to the same value as the actual value in the controller. In this way, both values will be zero.
What happens?
The controller is inhibited via the STO inputs at the i700 so that the motor does not generate any torque. Nevertheless, some setpoint and actual values are not zero in the i700 and are correspondingly transferred to the controller:
Effects on the controller application:
While the controller is inhibited (STO), the setpoints in the controller are set to the actual values transferred.
After deactivation of STO, unexpected drive movements may occur if the actual speed value is unequal zero.
When does this behaviour occur?
- In the V/f characteristic control motor control mode and
- if the controller is inhibited in a running motion process via the STO inputs at the i700.
Which products are affected?
- i700 servo inverter
Short-term measures:
Detect the inhibited state of the i700 via the controller application and adapt the transferred setpoint and actual values accordingly before they are processed further or displayed.If necessary, actively stop the axis via the application by means of appropriate functions, unless this has already been done.
Stronger measure with intervention in the PDO mapping to avoid even a short-time output of a speed setpoint unequal zero after controller enable:
- Define a global variable and
- go to the 'EtherCAT I/O Mapping' tab in the PLC Designer and assign this variable in the PDO mapping to the actual speed of the controller (actual velocity value).
In this way, the 'incorrect' actual speed from the i700 will no longer be accepted as speed setpoint. As a result, the i700 will be started with speed setpoint = 0 without speed jump.
Evaluation/recommendations:
If the above-mentioned setpoint and actual values are displayed via the machine visualisation, the machine operator could be misled.
