RedundancyManager (FB)¶

FUNCTION_BLOCK RedundancyManager

This FB can be used to manage MODBUS communication when using CODESYS Redundancy. It does NOT handle the case of both PLCs becoming standanlone and will activate MODBUS communication on both PLCs. When this FB is used I/O-Mapping should either only be done to exisiting variables or the addresses of the newly created variables need to be added to the “Registered Areas” of the redundancy configuration

InOut:

Scope	Name	Type	Comment
Input	xForceStart	BOOL	Can only be used to enable MODBUS communication on the second PLC in case of a startup without link and has no effect otherwise
Inout	client	IoDrvModbusTCP	Modbus Client Instance
Output	xRedundancyActive	BOOL	CODESYS PLC Redundancy is available
	PLC_ID	INT	PLC-ID = 1/2 if redundancy is activated
	RedundancyState	RDCY.RedundancyState	Current state of CODESYS PLC Redundancy
	xConnected	BOOL	Redundant PLCs can communicate via the configured redundancy link
	xSync	BOOL	Redundant PLCs are synchronized, for details see RedundancyState output
	xPrimary	BOOL	MODBUS TCP Client is Primary
	xBackup	BOOL	MODBUS TCP Client is Backup