1.1 Interactive schematic capture and layout in national instruments

Schematic capture in multisim

The benefits of integrated capture and simulation

Multisim provides users with the unique ability to capture and simulate from within the very sameintegrated environment. The advantages of this approach are many. Users new to Multisim do not have to worry about sophisticatedSPICE (Simulation Program with Integrated Circuit Emphasis) syntax and commands, while advanced users have easy access to all SPICEdetails.

Multisim makes capturing schematics easier and more intuitive than ever. A spreadsheet view allows users to easilymodify characteristics of any number of components simultaneously: from PBC footprint to SPICE model. Modeless operation provides themost efficient way of placing components and wiring them together. Working with both analog and digital multisection components isintuitive and simple.

In addition to traditional SPICE analyses, Multisim allows users to intuitively connect virtual instruments totheir schematics. Virtual instruments make it fast and easy to view interactive simulation results by replicating the real-worldenvironment.

Multisim also provides special components known as interactive parts which can be modified while a simulationis running. Interactive parts such as switches and potentiometers, will immediately and accurately affect the results ofsimulation.

When the need arises for more advanced analysis, Multisim delivers over 15 sophisticated analyses. Someexamples of analyses include AC, Monte Carlo, Worst Case, and Fourier. Provided natively within the Multisim environment is apowerful Grapher, which allows the customized viewing of simulation data and analyses.

The integrated capture and simulation environment provided by Multisim is a natural fit for any circuitdesigner, and will save both time and frustration throughout the entire circuit design process.

The multisim environment

Introducing the multisim environment

Multisim’s user interface consists of the basic elements, illustrated in Figure 1 below.

The design toolbox

The Design Toolbox is used to manage various elements in the schematic. The Visibility tab lets you choose whichlayers to display on the current sheet on the workspace. The Hierarchy tab contains a tree that shows the dependencies of thefiles in the design that you have open. The Project tab displays information about the current project. Users can add files to theexisting folders of the current project, control access to files, and archive designs.

Configuring global options

Global options allow users to configure specifics of the Multisim environment. They can be modified byaccessing the preferences dialog box. Choose Options/Global Preferences. The Preferences dialog box appears, offering you thefollowing tabs:

•Paths—where you can change the filepaths for the databases and other settings.

•Save—where you set up Auto-backup timing and whether you want to save simulation data with instruments.

•Parts—where you set up component placement mode and the symbol standard (ANSI or DIN). You also set up defaultdigital simulation settings.

•General—where you set up selection rectangle behavior, mouse wheel behavior, bus wiring and auto-wiringbehavior.

Configuring sheet options

The Sheet Properties dialog box is used to set up the preferences for each sheet. These preferences are saved withthe circuit file so that if the circuit is opened on another computer, it will use the same settings.

The sheet specific settings are arranged in the following tabs:

•Circuit—where you set the color scheme and the display properties of workspace text.

•Workspace—where you set the sheet size and properties.

•Wiring—where you set the wire and bus options.

•Font—where you select the font, font size and style for text elements on the circuit.

•PCB—where you set up options for your printed circuit board.

•Visibility—where you enable and disable custom annotation layers.

Consult the Multisim User Guide or Multisim helpfile for a detailed description of each sheet property.

Customizing the user interface

The Multisim user interface is highly customizable. Customizations are context sensitive. Toolbars may bedocked in various positions and orientations. The contents of the toolbars may be customized. New toolbars may be created. The menusystem is fully customizable, including all pop-up menus for the various object types.

As well, the keyboard shortcut system is customizable. This allows for key combinations to be assigned toany command that may be placed in a menu or on a toolbar.

Note: To avoid interfering with interactive simulation, it is recommended that users only assign commands tokey combinations (such as Ctrl-E).

For example, the toolbars and docking windows may be re-configured as you move from a circuit sheet to a description sheet.

To customize the user interface, select Options/Customize User Interface. Using the Customize dialog, userscan create or modify toolbars, assign or change keyboard shortcuts, customize and create menus, and modify the way the user interfaceappears.