Block (SysML item)
A Block is a modular unit that describes the structure of a system or other element of interest. It may include both structural and behavioral features, such as properties and operations that represent the state of the system and behavior that the system may exhibit.
Create a Block through a Modeler explorer pane or a Block Definition Diagram:
• In a Modeler pane, right-click the Model or a Package, point to New, point to SysML, point to Structure, and then click Block.
• In a Modeler pane, right-click the Block, point to New, point to SysML, and then click Block.
• On a Block Definition Diagram, click the Block button, and then click in free space.
Block button, and then click in free space.To specify that a Block is abstract: right-click the Block, point to Set, and then click Is Abstract. You can see if a Block is abstract through the Options tab of its Property Pages.
To specify that a Block is active: right-click the Block, point to Set, and then click Is Active. You can see if a Block is active through the Options tab of its Property Pages.
To specify that a Block is encapsulated: set the tagged value of its isEncapsulated tag definition to TRUE.
A Block can own Block Properties of type Part, Reference and Value: to create a Block Property, right-click the Block, point to New, point to SysML, and then click Block Property.
A Block can own Constraint Properties: to create a Constraint Property, right-click the Block, point to New, point to SysML, and then click Constraint Property.
When shown on a Block Definition Diagram, a Block's notation is as follows.
You can show compartments for the Block's roles and properties. To show a compartment: right-click the Block, click Show/Hide Compartments, and then select the check boxes associated with the roles and properties you want to show.
To populate a Block Definition Diagram with Blocks that are in the same Package as the diagram: on the diagram, right-click in free space, point to Populate, point to Nodes, and then click Blocks.
You can right-click a Block on a Block Definition Diagram, and through the commands on the Populate submenu, populate missing links that exist between the Block and other items.
All Blocks are shown in the 
Blocks tab - expand the Block folder. You can then expand a Block to view its Flow Ports, Flow Properties, Full Ports, Parts, Proxy Ports, References and Values.
Blocks tab - expand the Block folder. You can then expand a Block to view its Flow Ports, Flow Properties, Full Ports, Parts, Proxy Ports, References and Values.A Block is a UML Class that is stereotyped by the «Block» stereotype from the SysML profile.
The following sections provide information about how a Block is used in the model. For more information about a SysML diagram or item - click it.
Owned by
Model (UML item)
Package (UML item)Owns
Activity (UML item)
Allocate - the Allocate is owned jointly by the Block and the associated item. The access permissions you have to an Allocate are determined by the access permissions you have to the item that is allocated from - you require write access to both items to create or delete an Allocate.
Association (UML item) - the Association is owned jointly by the Block and the associated item. The access permissions you have to an Association are determined by the access permissions you have to the item at the start end of the Association. Allocate - the Allocate is owned jointly by the Block and the associated item. The access permissions you have to an Allocate are determined by the access permissions you have to the item that is allocated from - you require write access to both items to create or delete an Allocate.
Generalization (UML item) - the Generalization is owned jointly by the two Blocks it links. The access permissions you have to a Generalization are determined by the access permissions you have to the sub Block.
Item Flow - when the Block is used as the Item Flow's conveyed classifier (deleting the Block results in the Item Flow being deleted).
Interface (UML item)
Operation (UML item)
Reception
Refine (UML Standard profile) - the Refine relationship is owned jointly by the Block and the associated item. The access permissions you have to a Refine relationship are determined by the access permissions you have to the refined item.
Satisfy - the Satisfy relationship is owned jointly by the Block and the associated Requirement. The access permissions you have to a Satisfy relationship are determined by the access permissions you have to the Block.
Sequence Diagram (UML diagram)
Signal (UML item)
Standard Port (UML item)
State Machine (UML item)
Trace (UML Standard profile) - the Trace relationship is owned jointly by the Block and the associated item. The access permissions you have to a Trace relationship are determined by the access permissions you have to the item that is traced from.
Verify - the Verify relationship is owned jointly by the Block and the associated Requirement. The access permissions you have to a Verify relationship are determined by the access permissions you have to the Block.Shown on these diagrams
Sequence Diagram (UML diagram)SysML Properties
• allocatedFrom - lists source items that are linked through Allocate relationships (on Allocated tab when item is allocated).
• allocatedTo - lists target items that are linked through Allocate relationships (on Allocated tab when item is allocated).
• constraintProperties - lists Constraint Properties that the Block owns.
• constraints - lists Constraints that the Block owns.
• flowPorts - lists Flow Ports that the Block owns.
• flowProperties - lists Flow Properties that the Block owns.
• fullPorts - lists Full Ports that the Block owns.
• isEncapsulated - can be set to TRUE or FALSE.
• participants - lists Participants that the Block owns.
• parts - lists Blocks Properties of type Part that the Block owns.
• proxyPorts - lists Proxy Ports that the Block owns.
• references - lists Blocks Properties of type Reference that the Block owns.
• standardPorts - lists UML Ports that the Block owns.
• values - lists Blocks Properties of type Value that the Block owns.