DS Agile gateways
PC SCADA
T1000 switch
E01066
Px4x
Px4x
Px4x Px4x Px4x
Px4x
Px4x Px4x
H49
H49
H49
Bay 1 Bay 2 Bay 3
Figure 288: HSR application in the substation
5.4
RAPID SPANNING TREE PROTOCOL
RSTP is a standard used to quickly reconnect a network fault by finding an alternative path. It stops network loops
whilst enabling redundancy. It can be used in star or ring connections as shown in the following figure.
V01010
Switch 1
Switch 2
IED 1 IED 2
Switch 1 Switch 2
IED 1 IED 2
Star connection with redundant ports
managed by RSTP blocking function .
Ring connection managed by RST P
blocking function on upper switches
and IEDs interconnected directly .
Figure 289: IED attached to redundant Ethernet star or ring circuit
The RSTP implementation in this product is compatible with any devices that use RSTP.
RSTP can recover network faults quickly, but the fault recovery time depends on the number of devices on the
network and the network topology. A typical figure for the fault recovery time is 300ms. Therefore, RSTP cannot
achieve the “bumpless” redundancy that some other protocols can.
Refer to IEEE 802.1D 2004 standard for detailed information about the opration of the protocol.
P543i/P545i Chapter 22 - Communications
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