Schneider Electric 840 USE 106 0 manual Additional, Information, Going to Offline

Ethernet Hot Standby Solution

Step Action

8The Secondary NOE now becomes the Primary NOE.

9Primary NOE opens all client connections and listens for all server connections and re-establishes those connections.

10Simultaneously, Secondary NOE listens for all server connections and re- establishes those connections.

Additional	The following list provides additional information about the NOE’s IP addressing
Switchover	process resulting from a Hot Standby switchover.
Information
		Some MSTR/IEC Function blocks will not complete their transaction as a result
		of the IP Address swap.
	l	In this case, the MSTR/IEC Function block will return the error code 0x8000.
		While the NOE is in the process of performing the above actions, a new MSTR/
		IEC Function block may become active.
		No resources are available to service the new MSTR/IEC Function block.
		Therefore, the NOE will not service this new MSTR/IEC Function block, and all
		three output lines will be low.
Going to Offline
	When either the CPU stops or the Hot Standby state goes to offline mode, two
	events occur:
	1.	NOE mode goes to Offline
	2.	NOE uses the IP Address of the present configuration

IP Address Assignment and Going Offline

HSBY State	IP Address Assigned Is ...
Primary to Offline	Configured IP Address, if other controller does not go to
	Primary
Standby to Offline	Configured IP Address + 1

172 840 USE 106 00 January 2003