ABB Relion 670 Series Applications Manual page 490

Section 20
Security
overwritten. The list contents cannot be modified, but the whole list can be cleared using the
Reset menu in the LHMI.
The list of internal events provides valuable information, which can be used during commissioning
and fault tracing.
The information can, in addition to be viewed on the built in HMI, also be retrieved with the aid of a
PC with PCM600 installed and by using the Event Monitoring Tool. The PC can either be connected
to the front port, or to the port at the back of the IED.
20.3 Change lock CHNGLCK
20.3.1 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
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 ABB representative for remedial action.
484
Binary input signal that will activate/deactivate the function, defined in ACT or SMT.
1MRK 511 358-UUS A
GUID-B48775D0-ACF0-49C6-A7F6-69AF37F1C68F v1
GUID-51EEC9C7-8ECF-4546-BC26-326861654340 v4
GUID-8C333BC0-AA7A-4ED1-A772-18C22E8EEE62 v4
Application manual