User manual

Hot Standby
314
33002479 06 07/2008
IP Address Assignment
Configuring the
NOE
The NOE can be configured to work in conjunction with the Modicon Quantum Hot
Standby with Unity controller. Since the primary CPU and secondary controllers
must have an identical configuration, the configured IP addresses will be the same.
The NOE’s IP address is either the configured IP address or the configured IP
address +1. The current local Hot Standby state determines the IP address.
In the offline state, the IP address is determined by whether or not the other
controller is in transition to the primary CPU state.
The following table shows the IP address assignments.
IP Address
Restriction
Do not use either broadcast IP address or broadcast IP address - 2 to configure
an NOE.
Hot Standby State IP Address
Primary CPU Configured IP address
Standby CPU Configured IP address + 1
Transition from primary to offline Configured IP address, if peer controller does not
go to primary CPU
Transition from standby to offline Configured IP address + 1