Change Lock Chnglck; Application - Hitachi Relion 670 Series Applications Manual

Section 21
Security
21.3

Change lock CHNGLCK

21.3.1

Application

Change lock function CHNGLCK is used to block further changes to the IED configuration once the
commissioning is complete. The purpose is to make it impossible to perform inadvertent IED
configuration and setting changes.
However, when activated, CHNGLCK will still allow the following actions that does not involve
reconfiguring of the IED:
• Monitoring
• Reading events
• Resetting events
• Reading disturbance data
• Clear disturbances
• Reset LEDs
• Reset counters and other runtime component states
• Control operations
• Set system time
• Enter and exit from test mode
• Change of active setting group
The binary input controlling the function is defined in ACT or SMT. The CHNGLCK function is configured
using ACT.
LOCK
Change lock functionality can be temporarily disabled/overridden using Maintenance menu.
Maintenance menu/Recovery Menu (Password Protected)/Turn off Change-lock (Temporary).
Turning off the change-lock will override the change lock function until the next reboot of the IED. In this
case, the change lock function cannot be activated, and the Override output will indicate that the change-
lock is overridden.
308
Binary input signal that will activate/deactivate the function, defined in ACT or SMT.
When CHNGLCK has a logical one on its input, then all attempts to modify the IED
configuration and setting will be denied and the message "Error: Changes blocked" will be
displayed on the local HMI; in PCM600 the message will be "Operation denied by active
ChangeLock". The CHNGLCK function should be configured so that it is controlled by a signal
from a binary input card. This guarantees that by setting that signal to a logical zero,
CHNGLCK is deactivated. If any logic is included in the signal path to the CHNGLCK input,
that logic must be designed so that it cannot permanently issue a logical one to the
CHNGLCK input. If such a situation would occur in spite of these precautions, then please
contact the local Hitachi Energy representative for remedial action.
© 2017 - 2023 Hitachi Energy. All rights reserved
1MRK511407-UUS Rev. N
GUID-B48775D0-ACF0-49C6-A7F6-69AF37F1C68F v1
GUID-51EEC9C7-8ECF-4546-BC26-326861654340 v5
GUID-8C333BC0-AA7A-4ED1-A772-18C22E8EEE62 v8
Phasor measurement unit RES670
Application manual