Schneider Electric 840 USE 106 0 manual Hot Standby Topology, Drop

Ethernet Hot Standby Solution

Hot Standby Topology

Hot Standby The following diagram shows a Hot Standby system the relationship between the

Interconnection two redundant systems.Two CHS 110 modules are connected via a fiber optic link. The RIOs are connected both to each other and to the RIO Drops.

	N	C	C		R
	O	P	H		I
	E	U	S		O
Ethernet Switch			Fiber Optic	Cable		T Connector
	N	C	C		R
	O	P	H		I
	E	U	S		O

Drop Drop

Note: The following three items are important.

1.The two systems must be identical.

2.The order of the modules in each rack must be the same.

3.The software revisions must be the same.

In the preceding diagram the NOEs are connected to the same switch. Connecting to the same switch is recommended but not required. Connecting to the same switch is recommended because the NOEs communicate with each other in order to swap the IP address.

There are two reasons for connecting to the same switch:

If a failure to communicate between the NOEs occurs, the time to swap

lincreases.

Therefore to minimize the probability of a failure, connect the two NOEs to the same switch.

The other requirement for the switches is that they are on the same sub network.

166 840 USE 106 00 January 2003