Block Diagram Objects Overview
The following table describes the objects that you can insert in a block diagram. Each of these object has its own set of properties. For more information, see RBD Diagram Object Properties.
Diagram Object
Description
Connector
The lines that connect the nodes and blocks in the diagram. The points at which connectors attach to a node or a block are called connection points. By default, connectors enter blocks via the left connection point and exit them via the right connection point. You can use connectors to join blocks in nearly any conceivable configuration. A series configuration is one in which the blocks are joined in one continuous path, beginning at the start node and ending with the end node. A parallel configuration is one in which you typically insert a junction to split a connector into multiple connectors.
Block
A portion or component of the system being analyzed. You insert a block for each component to include in the analysis. You can link a block to a system tree item, FMEA item, mode, or cause, or a Weibull data set to use the failure data calculated for this linked item for the block. Comprehensive information about data linking appears in Data Links.
Junction
A special object that connects multiple connectors together. You can insert a junction to join two or more connectors to form a single connector or to split one connector off to form multiple connectors. Junctions can be inserted in any configuration to create a manual standby redundancy of multiple blocks in the diagram. Technically, the start node and end node in a diagram are junctions that have only one connection point. These nodes represent the start and end of the system analysis, and they cannot be deleted. The diagram is evaluated from the start node through all paths, until the end node is reached. The end node can support multiple inputs and have redundancies, just as any other junction you might insert.
Label
A text string that provides information that might be necessary or helpful to understanding some part of the diagram.
The RBD Diagram pane displays the diagram currently selected in the RBD Table. The commands for inserting objects in a diagram are described in Object Insertion Commands.
You can insert any number of blocks in a diagram. An independent block has no data link set to another item in the System file. You must supply calculation properties for all independent blocks. A linked block does have a data link set to another item in the System file. For a block, you can set a data link to any of the following items:
An assembly or part in the System Tree for either the FRACAS or Prediction module
A FMEA data record (item, mode, or cause)
A data set in the Weibull module.
A data-linked block uses the failure information that is calculated for the item to which it is linked. If you modify the calculation properties for this item, the next time that the diagram is calculated, the display-only information shown in the that block’s calculation properties is first updated.
For a block to be included in diagram calculation results, it must be part of a connected path in the diagram. Once you have inserted blocks for all components to analyze in the diagram and connected them from the start node through the end node, you select RBD > Verify RBD Data to verify diagram data, including inputs and output connections for blocks and junctions, in all or selected diagrams. For more information, see Verifying RBD Data.