The application i have in my project is to only read the values from the PLC and not control. And if the PLC we are connected to is lost (shutdown) our tags should shift over to the Redundant one. This post was very helpful and I think im missing a small trick here, Applying the the udt method where parameter name can be shifted to the other PLC when one PLC which we are connected to is lost ... will solve my problem.. If someone can help .. Thanks