i950 ES: Error saving safe position when using an externally powered encoder (no changes intended)
Corrected from:
i950 ES (Extended Safety): (currently no changes intended)
Response of the new version:
Currently no changes to the unit hardware are intended.
What happens?
The position reconstruction in the Extended Safety module does not work as expected under certain conditions, so that a position difference between the position value when switching off and switching on again is reported when switching on again, although the value has not actually changed.
When does the behaviour occur?
the safe position is to be stored in a power-failure-proof manner AND
an encoder system with external power supply is used, e.g. laser distance measuring system with SSI interface.
In the event of an error, the Extended Safety module from the i950 is supplied for a longer time than the externally supplied encoder. The external encoder will no longer transmit valid position values at last, but the Extended Safety module will store these faulty position values.
Which products are affected?
i950 ES (Extended Safety)
Short-term measures:
Ensure that the externally powered encoder remains powered for a longer period of time than the i950 unit or the Extended Safety module. This will ensure that the encoder's position values, which are valid until the end, are correctly stored in the Extended Safety module and that the position reconstruction works correctly when the unit is switched on again.
Evaluation / recommendations:
It should be considered whether the use of a buffered external power supply unit (UPS) to supply the external encoder is useful. Otherwise, the function for storing the position in the extended safety module in a way that is safe from power failure cannot be used and instead the safe referencing must be carried out again after each voltage switch.
