Which products are affected?
9300EP servo positioning controller version V2.1
What happens?
Home position is lost sporadically.
When does the problem occur?
In the positioning mode 'Absolute positioning with saving' (C1210 = 2) the home position was lost sporadically loss in the event of a brief mains disconnection if, for example, brief mains disruptions were generated in operations by a 'protective screen function'.
When power is switched off the status signal 'REF-OK' is reset as soon as the level of supply is below a certain voltage threshold.
If the mains or any external 24 V supply was switched back on again before the voltage supply to the control card had completely collapsed, the REF-OK state remained reset and another homing procedure was necessary.
Possible diagnostics?
Request status REF-OK.
Short-term measures/recommendations?
When a power-off has been initiated, wait until all voltage supplies have collapsed before switching back on again.
Evaluation:
Uncritical in terms of safety because if there is the home position is lost homing has to be repeated.
