Page 42 - ExtendSim User Guide
P. 42

Running a Model
Model basics
☞ Place your cursor over a connector to see its name and current value. You may also see addi- tional information depending on how the block is programmed.
Most blocks have a dialog associated with them. Dialogs are used to enter values and settings before running simulations and to see results as the simulation runs.
To open a block’s dialog, double-click the block’s icon, or right-click the icon and select Open Dialog. For example, if you double-click the Holding Tank icon, the dialog at right opens.
At the top of the dialog is the block’s global block number, its name, and, in braces, the library it resides in. Global block numbers are unique identifiers assigned sequentially to blocks as they are placed in a model.
At the bottom of every dialog is a Help button. The
block’s Help provides information about the block,
such as its purpose and use, connector usage,
descriptions of each dialog item, and so on. Beside
the Help button is a text box where you can enter a
label for the block, up to 31 characters. The View popup is for changing the icon’s orientation or appearance when you build models—for example, the Holding Tank offers a choice of Default View and Default View Reverse.
Some dialogs also calculate and display values that are generated as the model runs, so if you leave a dialog open during the simulation, you can watch the impact on different variables. This interactive simulation capability means you can even change some of the settings in a dialog during a simulation run, such as choosing different buttons or typing new values.
☞ When you click a button while the simulation is running, the block gets that changed value on the next step. However, if you type text or enter numbers into a parameter field, the model pauses while you are typing in order to get your entire input.
Connections are the lines that are used to join blocks together. They represent the flow of infor- mation from block to block through the model. The simulation itself is a series of calculations and actions which proceed along the path of the connections repetitively. Each repetition is called a step for continuous models or event for discrete event and discrete rate models.
In the Reservoir model, the blocks calculate in an order determined by the connections, starting at the left and going to the right.
Holding Tank dialog

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