Clarifications on the local/remote concept 8/8
IEC 61850-7-4 Ed2.1 ,7-5
Annex B, Table B.1 states that "Manual Control at switch (process)" was always allowed. Isn't it the status of a control switch modelled as XCBR.LocKey="true" which releases the manual control at the switchgear? As long as this control switch is not activated, manual control is not possible. To prevent from switchgear controls other than local during this time, as long as XCBR.LocKey="true", no control issued by the IED is accepted.
In part 7-4 "Manual Control at switch (process) is always allowed" means a mechanical action, independent of the IED status.
Part 7-4 states that if XCBR.LocKey="true", then commands received via IEC 61850 control services will be blocked.
If XCBR.LocKey="true", then the IED may process control requests received directly by the IED, e.g. from the IED front panel HMI or push-buttons wired directly to the IED. There may be proprietary settings to enable or disable this feature.