WG10 Future Work #5965
Schedules - allow updates to single values while schedules are running
Context: how to use IEC 61850 for DER and microgrids (IEC 61850-90-23 CD1).
IEC 61850-7-4 prescribes that schedules may only be updated whilst they are offline. This is a conservative approach that allows for validation of all the settings to ensure consistency before re-starting i.e. evaluating the schedule output.
There are two approaches:
1. Stop the running schedule; change it, restart
2. Write to another schedule with a higher priority and start that; stop the original schedule; change it, restart it; stop the second schedule.
This approach is unnecessarily complex for some cases. A common use case is to update a schedule for one or more periods in the future. In these cases, updating individual schedule values will not affect the current schedule output, so there is no need to require the schedule to be deactivated and reactivated.
See also #3098
Updated by Tom Berry about 1 year ago
Discussed in WG10 Meeting September 2022
The key issue is to clarify the consistency checks made when updating a FSCH.
The FSCH state machine is used to ensure that a schedule is consistent before it is enabled, but part 7-4 Annex K does not provide details of the checks that must / should be performed.
Tom Berry to write a proposal to describe expected checks for each data object.
For example, changing the number of points needs a full consistency check, changing a single ASG value does not.