Defining module inputs and module outputs

To allow model entity values to be used as values in a module, you must define module entities as either module inputs or module outputs.

A module input is an entity in the module (a stock, a flow, or a converter) that contains information that the module needs in order to run. Although you can explicitly define an entity as a module input, you are not required to; when you assign an entity as a module input (by using the Assign Input To command), that entity is automatically made a module input.
A module output is an entity in the module that contains information generated by the module and that can supply a value to other connected entities or modules. Entities directly connected into a module (via a connector from the entity to the module) can be assigned to a module input in the connected module without explicitly defining them as outputs. These entities are providing data into the connected module. On the other hand, entities that are providing data out of the module (into the model that contains the module, or into another module) must be explicitly defined as outputs.

Note: You can also define an entity to be neither a module input nor a module output by selecting the Neither option.

To define an entity as a module input or module output

Navigate into the module for which you want to define an entity as a module input or output.
Right-click the entity that you want to define, choose Module, and then choose Accept Input, Provide Output, or Neither.

Note: Changing an entity’s input/output definition disconnects any existing assignments made between that entity and another entity.