The following table describes the types of object nodes that you can use to model object flow in activity diagrams.
| Object node type | Description | Icon |
|---|---|---|
| Activity parameter | This node specifies the input and output parameters for the activity. | ![]() |
| Central buffer | This node consolidates data from several sources and destinations. Central buffer nodes do not connect directly to actions. | ![]() |
| Data store | This node models data flow in which the data is persistent. | ![]() |
| Input pin | This node represents the input parameters on an action. The input pin holds the input values that are received from other actions. | ![]() |
| Output pin | This node represents the output parameters on an action. The output pin holds the output values that an action produces. Object flow edges deliver the output values to other actions. | ![]() |
| Value pin | This node represents the input parameter on an action. The action is enabled when the value pin, which holds a specific value, is evaluated. The result of a "successful" evaluation is the input to the action. | ![]() |