SimEvents

Discrete-Event Simulation in Simulink

SimEvents provides a discrete-event simulation engine that manages and processes sequences of asynchronous events. These events can help model mode changes and trigger state transitions within time-based systems in Simulink.

Entities and Events

With SimEvents you can create entities to represent discrete items of interest, such as packets in a communication system or airplanes in an airport taxiway. The generation, movement, and processing of entities in the system causes events, such as the arrival of a packet or the departure of an airplane. In turn, these events modify the states in the system to affect system behavior. You can characterize your entity with attributes, such as a destination address, processing time, or server delay. SimEvents distinguishes between entity lines, which represent entity movement between blocks, and event-signal lines, which denote corresponding event-based computations, via unique port styles.

Capacity Planning Simulation for Manufacturing Processes 8:04
Use SimEvents as a production simulation tool to identify bottlenecks in a production process and to come up with better inventory management techniques.

Integrating SimEvents with Simulink and Stateflow

SimEvents lets you integrate event-based modeling into time-based Simulink models by using blocks from the Gateway library. The Timed-to-Event Signal block converts time-based signals to event-based signals; conversely, the Event-to-Timed Signal block converts events back to time-based signals. Using this bidirectional conversion, you can model discrete mode-switching in time-based components as well as communication between time-based components.

Model of an antilock braking system (ABS) using CAN communications and supporting plots showing how network utilization (above right), message delivery delay (below right), and vehicle and wheel speeds (bottom left) are affected by overall CAN traffic.

You can operate directly on event-based signals using Simulink and Stateflow^® library blocks, including Math Operations, MATLAB Function, Stateflow Charts, and Logical Operator. You can also encapsulate any Simulink calculation that needs to operate on an event-based signal using the Atomic Subsystem block.

Model of a CAN node that uses a MATLAB Function block, an atomic subsystem, and a math operation (Gain block) to alter SimEvents signals.