ABB Relion 670 series - Denial of Service SCHLCCH;RCHLCCH

The binary input controlling the function is defined in ACT or SMT. The CHNGLCK
function is configured using ACT.
LOCK 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.
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.
The functions Access point diagnostics function block measure the IED load from
communication and, if necessary, limit it for not jeopardizing the IEDs control and
protection functionality due to high CPU load. The function has the following denial of
service related outputs:
• LINKSTS indicates the Ethernet link status for the rear ports (single communication)
• CHALISTS and CHBLISTS indicates the Ethernet link status for the rear ports
channel A and B (redundant communication)
• LinkStatus indicates the Ethernet link status for the front port
1MRK 506 369-UUS - Section 23
Security
Line distance protection REL670 2.2 ANSI 893
Application manual