ABB Relion 670 Series Applications Manual page 491

1MRK 511 358-UUS A
20.4 Denial of service DOS
20.4.1 Application
The denial of service functions (DOSFRNT, DOSLANAB and DOSLANCD) are 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.
DOSFRNT, DOSLANAB and DOSLANCD 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 outputs:
• LINKUP indicates the Ethernet link status
• WARNING indicates that communication (frame rate) is higher than normal
• ALARM indicates that the IED limits communication
20.4.2 Setting guidelines
The function does not have any parameters available in the local HMI or PCM600.
Application manual
Section 20
Security
GUID-64F4D905-9F73-4073-B8F6-8D373155316A v4
GUID-CE3344E8-539B-47E0-9C19-8239988BDBCF v2
485