Archived: Learning How to Use the New Schematic Capture Net System in NI Multisim 11

Publish Date: Nov 13, 2017 | 8 Ratings | 3.25 out of 5 | Print | Submit your review

Overview

This document has been archived and is no longer updated by National Instruments.

In Multisim 11.0, we have completely re-architected our schematic capture environment, allowing you to quickly create circuit diagrams that are easy to read. Innovative new features now include new connectors that will make net naming and connection clearer to improve design communication.

In this tutorial you will learn a number of new concepts, and will be able to benefit from brand new connectors to improve your design approach. Finally we will also provide best-practices when transitioning from legacy schematics to the new Multisim 11 environment.

Table of Contents

  1. Introduction
  2. Watch a Video on Using Connectors
  3. Glossary
  4. Benefits of Using Connectors
  5. Tutorial on How to Use the New Connectors
  6. Transitioning Old Designs to the New Schematic Capture System

1. Introduction

The new schematic capture net system in NI Multisim provides a number of benefits to the user. Most notably engineers can take advantage of an up-to-date and intuitive circuit design environment. As a part of the complete re-architecture to our schematic capture environment in Multisim 11, users can now place a host of different connectors to symbolize the virtual connections in their designs.

New on-page and global connectors are now available. By using these new features you will instantly be able to:

  1. Improve your approach to drawing schematics with clearer indication of net connections
  2. Make circuit files more stable (less likely to be corrupted)
  3. Avoid unnecessary errors made by improper wiring and forgotten connections
  4. Quickly get started with a design, regardless of the last time you had worked with it
  5. Communicate schematics and design decisions to management easier

By reading this tutorial you will learn more about on-page and global connectors, when and how to use them, and finally how to transition from using our legacy schematic capture environment.

 

 

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2. Watch a Video on Using Connectors

The following is a short 3 minute video on using on-page and global connectors.

 

If you are interested in learning more about other new features in NI Multisim, I recommend viewing 7 other 3-minute videos at ni.com/multisim/upgrade.

 

 

 

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3. Glossary

Connectors allow you to show connections on a schematic without having an actual wire drawn between two objects. The connector indicates to the viewer that a specific wire is connected to another wire in the circuit. By using such connectors you can clear up a design and avoid spaghetti wiring and poor naming conventions (hallmarks of a ineffective schematic).

You can access these connectors by going to Place >> Connectors (Figure 1). You will notice that there are two options here of note; "On-Page Connector" and "Global Connector".

Figure 1 - Place a Connector

 

On-Page Connectors

An on-page connector shows a connection on a single schematic page. If you have two wires that you would like to have connected together on one page of your design then you can use a on-page connector. In figure 2 below you will see that the oscilloscope and output of the circuit are connected together through the on-page connector named "Output".

Figure 2 - On-Page Connectors

 

 

Global Connectors

A global connector, similar to an on-page connector creates a connection between various wires. However a global connector is not limited to a single schematic page. A global connector can be used to create connections through hierarchy (sub-circuits, hierarchical blocks and multiple-pages).

 

 

 

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4. Benefits of Using Connectors

In the past when creating a connection between two separate wires you would create a virtual connection symbolized by a "hanging junction". The only way one could properly ascertain that the wire is connected to another wire is through the net-name. This can be cumbersome, and from a visual perspective can be difficult to view. 

Considering that schematics must often be viewed by others (colleagues, management etc...) a design diagram that is difficult to read can cause confusion.

Poor wiring can cause mistakes. Often engineers will inadvertently make a connection between wires and components that make their designs function erroneously. As such the legacy method of virtual connections can be prone to mistakes.

 

Figure 3 - Legacy Connections

 

With the new on-page and global connectors these issues can be overcome. Engineers can now very clearly identify a connection between nets as seen in previous examples in this tutorial. Design decisions can be very clearly communicated through all of these various tools whether to fellow engineers or management. 

An important by-product of all of these changes is that design errors caused by potential wiring mistakes are minimized. Poor wiring and improper connections are removed from the design flow, and a best practices approach is achieved.

 

 

 

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5. Tutorial on How to Use the New Connectors

The following tutorial will provide you a quick introduction to using the connectors in Multisim. 

  1. Open Multisim (Start > All Programs > National Instruments > Circuit Design Suite 11.0 > Multisim 11.0)
  2. Select Open > File … and open the NetTutorial.ms11 file (attached in the 11219_tutorial.zip folder at the bottom of this tutorial)

Figure 4 - Example File for Tutorial

 

  1. We will begin by using an on-page connector. The on-page connector allows you to create a virtual connection between nets on a single-page, but does not exist outside of the page it is placed upon. It is therefore a “local” connector. Select Place > Connectors > On-Page Connector
  2. Connect the On-Page connector to the 12V supply (V7 on the diagram).
  3. The “On-Page Connection” dialog box (Figure 5) will appear. Name the connection V_POS. Click on OK.

Figure 5 - On-Page Connection Dialog Box

 

  1. The schematic will now look like figure 6. Next place another On-Page Connector to complete the connection.
    Select Place > Connectors > On-Page Connector.

Figure 6 - DC Power Supply

 

  1. Connect the On-Page connector to the U2 Op-Amp on the wire connected to the #7 pin.
  2. This time select the name “V_POS” from the list of the connectors in the “On-Page Connection” dialog box (Figure 7). 
  3. Click on the OK button.

Figure 7 - Making the V_POS Connection

 

  1. The virtual connection has been created between the two nodes (Figure 8).

Figure 8 - Competed Connection

 

  1. We will next use a global connector. The global connector allows you to create a virtual connection between nets throughout a design – whether the connection is on the same-page, through a sub-circuit or through a hierarchical block.
  2. Select Place > Connectors > Global Connector.
  3. Connect the Global Page connector to the 12V supply (V6).
  4. Name the connector V_NEG. Click on the OK button.
  5. Select Place > Connectors > Global Connector
  6. Press “CTRL” and “R” on your keyboard twice to rotate the connector 180 degrees.
  7. Connect the Global Page connector to the U2 Op-Amp on the wire connected to the #4 pin.
  8. This time select the name “V_NEG” from the list of the connectors in the “On-Page Connection” dialog box. Click on the OK button.
  9. The virtual connection between the two nodes will be created (Figure 9)

Figure 9 - Global Connectors

 

  1. To truly illustrate the differences between on-page and global connectors we will see how these connectors work through hierarchy (i.e. sub-circuits and hierarchical blocks). Double-click on HB1 (also named SF_1).
  2. In the “Hierarchical Block/Subcircuit” dialog click on Edit HB/SC.
  3. Notice that the negative voltage rail on the operational amplifier is not connected to a power source (Figure 10).

Figure 10 - Unconnected Power Supply

 

  1. Select Place > Connectors > On-Page Connector
  2. Press “CTRL” and “R” on your keyboard once to rotate the connector 90 degrees.
  3. Connect the On-Page Connector to the wire. Notice that the dialog box lists the V_NEG connector, but not the V_POS connector (Figure 11). This is because V_NEG is a global connector and it exists throughout the design (including through hierarchy).

Figure 11 - Making a Global Connection

 

  1. Click on the OK button. Notice that the connection has been created.

 

 

 

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6. Transitioning Old Designs to the New Schematic Capture System

 

For those of you that would like to read a detailed example on transitioning to the new schematic capture system, I highly recommend you read the following knowledge base article: Opening Old Designs in Multisim 11 (or Higher) New Objects are Added

 

The new schematic capture net system (onpage and global connectors, new bus labels, net net naming) facilitates far more solid and stable designs. Circuit files are less likely to be corrupted, and designers are less likely to overlook virtual connections (thereby inadvertently short-circuiting nets).

However, to permit such a significant new feature National Instruments did need to re-architect Multisim. This does mean that the "old" net system and legacy design approaches have been made obsolete. When converting or upgrading old designs into Multisim 11 your circuit file will take on the characteristics of the "new" system.

Figure 12a - Multisim 10.x File

 

 

Figure 12b - Conversion of Multisim 10.x File to Multisim 11.0

 

 

This conversion process of old designs does mean that old virtual connections, hierarchical blocks, subcircuits, and buses, will be visually changed. Virtual connections will be replaced by connectors, new labels will be added to buses and nets within blocks will now have a unique net name across the project. If your designs make use of these aforementioned features, you will need to perform a one-time review of your design to ensure the automatically placed connectors are not overlapping objects (such as other wires and connectors). 

This one-time review is highly recommended and necessary for a smooth transition to those that migrate old designs to Multisim 11. Though this may take time initially we strongly encourage you to do so in order to benefit from all the new features of Multisim 11 (including Forward and Backwards Annotation). The time it will take is dependent on your project and how heavily you have used virtual connections, blocks and buses. 

 

Once more for those of you that would like to read a detailed example on transitioning to the new schematic capture system, I highly recommend you read the following knowledge base article: Opening Old Designs in Multisim 11 (or Higher) New Objects are Added

 

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