Page 119 - ExtendSim User Guide
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Concepts, Tips, and Techniques 93
Mixing block types
solutions that solve the DAG (Directed Acyclic Graph) ordering problem, and it is possible for the less desired solution to be picked.
To solve this ordering problem, start with the model set to Flow order and then change the order for a few selected blocks using the Model > Set Simulation Order command.
☞ To use the Custom order option effectively, the Model > Show Simulation Order command should be checked so that the user can see which blocks need a changed order.
Also, note that the Set Simulation Order command is not enabled unless Custom order is selected and a block is selected.
In the Set Simulation Order dialog, you can enter a new order number for the selected block and it will be moved into that position in the simulation order.
Note that any custom order is lost if either Flow order or Left to right order is selected again.
Mixing block types
Set Simulation Order dialog
You can use continuous blocks, such as
those from the Value library, in discrete event and discrete rate models. You cannot, however, use discrete event or discrete rate blocks in continuous models. All blocks in the discrete event and discrete rate libraries require an Executive block that changes the timing of the model to event timing.
☞ The types of modeling you can perform depend on your ExtendSim package.
To learn more about what types of connectors can be connected to each other, see “Connector
types” on page 574.
Connections to multiple inputs
In a continuous model, you can connect from one output connector to as many input connectors as you want. Multiple inputs from one output is useful when many blocks need the results of a preceding block. For instance, if you have one output connector connected to four input connectors, the model might look like the image at top right.
☞ As discussed in“Event scheduling” on page 316, the connec- tions work differently in discrete event models.
For aesthetic reasons, you may want to only have one con- nection coming from the output connector, for example when the blocks are far away from each other. Instead of four connections, connect to one of the input connectors, then connect the input connectors together (sometimes called daisy-chaining) in the image at bottom right. (Note that this method may be confusing to others trying to understand the model.)
One value output connected to four inputs in a continuous model
Four value inputs connected together

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