ABB Relion 670 Series Applications Manual page 584

Section 23
Security
23.3 Change lock CHNGLCK
23.3.1 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
23.4 Denial of service SCHLCCH/RCHLCCH
23.4.1 Application
The denial of service functionality is designed to limit the CPU load that can be produced by
Ethernet network traffic on the IED. The communication facilities must not be allowed to
compromise the primary functionality of the device. All inbound network traffic will be quota
controlled so that too heavy network loads can be controlled. Heavy network load might for
instance be the result of malfunctioning equipment connected to the network.
578
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 ABB representative for remedial
action.
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1MRK 511 401-UEN Rev. K
GUID-B48775D0-ACF0-49C6-A7F6-69AF37F1C68F v1
GUID-51EEC9C7-8ECF-4546-BC26-326861654340 v4
GUID-8C333BC0-AA7A-4ED1-A772-18C22E8EEE62 v6
GUID-64F4D905-9F73-4073-B8F6-8D373155316A v5
Bay control REC670
Application manual