2.1. Launching Simulink and the Start Page

Understanding the Simulink user interface is fundamental to effective modeling. The workspace is more than just a blank canvas; it is a powerful and structured environment designed for model creation, component management, and simulation control. Familiarity with its key components will enable a smooth and efficient workflow.

There are two distinct methods for launching the Simulink environment from within MATLAB:

1. Method 1: Using the MATLAB Command Window: The most direct method is to type the command simulink into the MATLAB Command Window and press the Enter key. This command initializes and opens the Simulink Start Page.
2. Method 2: Using the MATLAB Toolbar: Alternatively, you can launch Simulink graphically by clicking the Simulink icon located in the main toolbar of the MATLAB interface.

Upon launching, you are greeted with the Simulink Start Page. This page serves as your initial portal into the environment. From here, you can choose to create a new blank model, a blank subsystem, or a blank library. It also provides a variety of built-in templates, which are pre-populated models that serve as excellent starting points for common tasks and can help accelerate your learning and development.

For our purposes, we will begin with a Blank Model, which will guide us from the Start Page to the primary workspace where all model construction occurs.

2.2. The Model Window and the Library Browser

After selecting “Blank Model” from the Start Page, you are presented with the Model Window. This window is the main canvas where you will build, connect, and organize your block diagrams. It is crucial to save your work frequently using the “Save” button in the toolbar.

The core components used to build any model are found within the Simulink Library Browser. This browser can be thought of as an engineer’s virtual toolkit, containing everything from basic arithmetic components analogous to resistors and adders, to complex, specialized instruments like oscilloscopes (Scope) and function generators (Signal Generator). It is the central repository containing all available blocks, organized into a comprehensive set of libraries categorized by function.

Below is a detailed overview of the key libraries and their purposes:

• Commonly Used Blocks
  • This library contains a curated collection of the most frequently used blocks, providing quick access to essentials like the Constant, Sum, and Gain blocks.
• Continuous
  • Essential for modeling systems described by differential equations. It contains blocks for performing calculus operations, such as Derivative and Integrator.
• Dashboard
  • Provides a set of blocks for creating interactive controls and indicators (like knobs, sliders, and gauges) directly on your model canvas, allowing you to tune parameters and visualize signals during a simulation.
• Discontinuities
  • Contains blocks that model nonlinear and discontinuous functions, such as Saturation, Dead Zone, and Relay.
• Discrete
  • Used for modeling discrete-time systems. It includes blocks that handle time-relation functions, such as Unit Delay.
• Logic and Bit Operations
  • Provides blocks for implementing logical constructs, including relational operators (<, >), logical operators (AND, OR, NOT), and bitwise operations.
• Lookup Tables
  • Used to implement functions by interpolating output values from a given set of input data points. This is particularly useful for modeling nonlinear system characteristics defined by empirical data.
• Math Operations
  • A fundamental library containing blocks for a wide range of mathematical functions, from basic arithmetic (Add, Subtract, Product, Divide) to more complex operations.
• Messages & Events
  • Contains blocks for modeling communication protocols and event-based systems.
• Model Verification
  • Includes blocks that help you perform self-verification on models to check for properties like valid input ranges.
• Model-Wide Utilities
  • Provides utility blocks that offer information or support for the entire model, such as Model Info.
• Ports & Subsystems
  • Contains blocks for creating hierarchical models. Key examples include Subsystem, Switch Case, and Enable.
• Signal Attributes
  • Allows for the modification of signal properties, such as data type, using blocks like Data Type Conversion.
• Signal Routing
  • Contains blocks used to manage and direct the flow of signals within a model. Key blocks include Switch, Selector, and Bus Creator.
• Sinks
  • The “Sinks” library provides blocks used to terminate signals, typically for visualization or data export. The most important blocks here are the Scope, which acts like a virtual oscilloscope to plot signals over time, and To Workspace, which exports signal data to the MATLAB workspace for analysis.
• Sources
  • This library is the starting point for most models. It contains blocks that generate signals or import data into the simulation. A primary example is the Sine Wave block, but it also includes blocks for constant values, step inputs, and signal generators.
• String
  • Includes a collection of blocks for creating and manipulating string data within a model.
• User Defined Functions
  • This powerful library allows you to extend Simulink’s capabilities with your own custom logic. Notable blocks include the MATLAB Function, MATLAB System, Simulink Function, and Initialize Function.

This module has familiarized you with the three core components of the Simulink environment: the Start Page, the Model Window, and the Library Browser. With a foundational understanding of the workspace, we can now proceed to learn how to use the fundamental elements within it: blocks and the lines that connect them.