Use local I/O addresses

Local addresses to I/O data are used when each View node has its own I/O Server. This architecture provides fault-tolerant operation, as each View node can continue to run independently if the network goes down.

In the following figure, two View nodes run copies of the same application that refer to their own I/O data source. Because each application uses a local I/O address for the data source, each reference points to the local I/O Server.

Using a local I/O Server significantly increases the load on the process connection network. For example, three nodes triples the traffic created by one node, as each node's requests must be separately processed.

For more information about defining an Access Name for a local I/O Server, see Data access with I/O in AVEVA™ InTouch HMI Application Development.