Sequence Viewer

Display messages, events, states, transitions, and functions between blocks during simulation

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Libraries:
Simulink / Messages & Events
Simulink Test
SimEvents
Stateflow

Description

The Sequence Viewer block displays messages, events, states, transitions, and functions between certain blocks during simulation. The blocks that you can display are called lifeline blocks and include:

• Subsystems

• Referenced models

• Blocks that contain messages, such as Stateflow^® charts

• Blocks that call functions or generate events, such as Function Caller, Function-Call Generator, and MATLAB Function blocks

• Blocks that contain functions, such as Function-Call Subsystem and Simulink Function blocks

To see states, transitions, and events for lifeline blocks in a referenced model, you must have a Sequence Viewer block in the referenced model. Without a Sequence Viewer block in the referenced model, you can see only messages and functions for lifeline blocks in the referenced model.

Note

The Sequence Viewer block does not display function calls generated by MATLAB Function blocks and S-functions.

Examples

Trigger a Discrete-Event Chart Block on Message Arrival

Trigger a Discrete-Event Chart Block on the message arrival when generating parts in a facility and performing quality assurance. In the example, behaviors of a Discrete-Event Chart and Stateflow® Chart blocks are compared. Both blocks require a Stateflow® license. The example shows that, a Discrete-Event Chart block executes immediately upon the arrival of a message and does not wait for the next sample time hit.

• Open Model

Dynamic Scheduling of Discrete-Event Chart Block

Use the dynamic scheduling that the Discrete-Event Chart block provides. A Discrete Event Chart block can execute zero or multiple times in a time step. The example compares the behaviors of the Discrete-Event Chart and Stateflow® Chart blocks. Both blocks require a Stateflow® license.

• Open Model

Parameters

Time Precision for Variable Step — Digits for time increment precision

3 (default) | scalar

Number of digits for time increment precision. When using a variable step solver, change this parameter to adjust the time precision for the sequence viewer. By default the block supports 3 digits of precision.

Suppose the block displays two events that occur at times 0.1215 and 0.1219. Displaying these two events precisely requires 4 digits of precision. If the precision is 3, then the block displays two events at time 0.121.

Programmatic Use

Block Parameter: VariableStepTimePrecision

Type: string scalar or character vector

Values: "3" | scalar

Default: "3"

History — Maximum number of previous events to display

5000 (default) | scalar

Total number of events before the last event to display.

For example, if History is 5 and there are 10 events in your simulation, then the block displays 6 events, including the last event and the five events prior the last event. Earlier events are not displayed. The time ruler is greyed to indicate the time between the beginning of the simulation and the time of the first displayed event.

Each send, receive, drop, or function call event is counted as one event, even if they occur at the same simulation time.

Programmatic Use

Block Parameter: History

Type: string scalar or character vector

Values: "1000" | scalar

Default: "1000"

Block Characteristics

Data Types	Boolean | bus | double | enumerated | fixed point | integer | single
Direct Feedthrough	no
Multidimensional Signals	yes
Variable-Size Signals	no
Zero-Crossing Detection	no

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

This block can be used for visualizing message transitions during simulation, but is not included in the generated code.

Version History

Introduced in R2015b