Many systems operate in a hierarchical fashion that leave individual computers vulnerable to system failures anywhere on the network. The architecture of iFIX allows plants to distribute critical functions among all nodes on the network.
In a distributed processing network, each node independently executes the tasks assigned to it. One advantage of this strategy is that nodes can be taken off-line without bringing the whole network down. When a node looks for data from an off-line node, the networking application notifies the requesting node, so that the node handles the missing data gracefully. Even though each node has integrity as an independent station, nodes can also access data anywhere on the network. For example, an iClient can display a picture with links to many different SCADA nodes without requiring additional configuration work or the need to have a local copy of the database.
Sessions
With iFIX, you can selectively configure which nodes can access data from a SCADA node on the network. A communication link between two nodes over a network is called a session. When a node establishes a session with a SCADA node, data and alarms can be sent between the nodes. The following figure illustrates session communication.
Network Session
Dynamic Connections
You can also configure your node to automatically make connections online to remote SCADA nodes that are not specifically configured on your node. These connections, called dynamic connections, are described in more detail in the Configuring Remote Nodes section in the Setting up the Environment manual.
