Connections define the structure of the tree. A branch in the tree attaching one node to another is a connection. A connection coming out of the top of a node indicates that the node is a predecessor to the connection and the node is providing its output to the connection. A connection going into the bottom of a node indicates that the node is the successor to the connection and that the connection is providing input to the node. For this reason, fault trees are generally oriented from bottom to top with basic events that are inputs only at the bottom. Derived events that have inputs and provide output are arranged moving upward until there is a single node at the top with only inputs. Arranged in this way data in a fault tree always travels upward. With Auto Arrange on (FAULT TREE | Display | Auto Arrange), DPL will automatically arrange nodes in this way when you connect them regardless of how they were placed before the connection was made.
Connecting Nodes and Gates
Connect two nodes as follows.
- Click on FAULT TREE | Connection | Add. The cursor changes to the begin connection cursor.
- Click on the predecessor (node which provides an input). The cursor changes to the finish connection cursor.
- Click on the successor (node which takes the input).
Shortcuts for Connecting New Nodes to Existing Nodes
DPL provides some shortcuts for connecting new nodes to existing nodes.
With the Auto Arrange feature turned on, place a new node on top of an existing node. DPL will automatically connect the two with the new node being a predecessor to the existing node and the new node being placed below the existing one.
You may also shift+click a node to begin creating a connection between it and another node.
To delete a connection, click on the connection, then press the Delete key.
NOT gates are specified on connections. For more information, see Gates.
Versions: DPL Fault Tree