Page 640 - ExtendSim User Guide
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614 Model Execution
How ExtendSim passes messages in models
• Block-to-block. Updates the status of other blocks in the model.
To avoid modeling errors and simulation speed issues in discrete event models, it is important to understand how the discrete event messaging architecture works. See “Messaging in dis- crete event models” on page 319 for additional information.
Discrete rate block messaging
In addition to receiving application messages, discrete rate blocks intensively use messages in order to initiate the calculation of the effective rates and to propagate information through the blocks. These block messages fall into the following categories:
• Event. Communication between the Executive block and various Rate library blocks.
• Valueconnector.Notifiesconnectedblocksthatthevalueofaoutputconnectorhas
changed or requests updated input connector information.
• Flow connector. Updates the effective rate through the connected blocks.
• Rate blocks flow. Defines the LP area – that part of the model that could be impacted by a
change in the effective inflow and outflow rates.
• Executiveflow.UpdatesalltheblocksinanLPareawithaneweffectiverate.
The discrete rate technology has a complex and unique messaging architecture. For optimal performance, it is important to understand discrete rate messaging when building rate-based models. For more information, see “Block messages” on page 459.
How To

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