Response of the new version:
All actual values of the i700 transferred as process data (PDO) to the control system come from the same control cycle. I.e. the data is timewise consistent.
What happens?
The actual values (setpoint and actual position, following error) transferred as EtherCAT process data (PDO) to the control system may come from different task cycles of the i700. A time offset of 0.250 ms occurs. The position values are thus timewise not consistent.
When does this behaviour occur?In principle, the behaviour occurs always. Actually, it does, however, only show effect under certain conditions.
In particular, if the actual values transferred are used for the touch-probe functionality in the controller application, the calculated TP position will deviate proportionally to the speed as a result. When determining the position system deviation (following error) in the application, a correspondingly higher value will be calculated.
Which products are affected?
- i700 servo inverter
Short-term measures:
None.
Evaluation/recommendations:
The above-described behaviour will only have practical effects to a very limited extent.
Significant effects are only to be expected if the touch-probe functionality is used in the controller application, e.g. to control the setpoint position of a following axis. Since the setpoint position calculation by means of the determined TP position is to be considered as a one-off event, deviations will have more serious effects.
In contrast to this, deviations of the cyclically calculated following error will not lead to a permanent deviation of the target position after reaching the target.
In most cases, the effects of the described behaviour can only be made visible when directly comparing the following error calculated in the control system with the following error calculated in the i700.
