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Knowledge Item

DesignSpark PCB - Schematic Buses overview

Posted by Mike Brojak


Schematic Buses - overview

This Knowledge item is an overview of the Schematic Buses function - one of the new features introduced in DesignSpark PCB Version 5 in response to the user community requests for this functionality

What is a Bus?

A bus is a shape that represents a collection of signals on the Schematic design. Instead of drawing all the connections across the design and connecting them to every pin required, you can make the design less cluttered by using busses. You can add connections from a component pin to the bus that carries the signal.


Busses can be Open or Closed. A Closed Bus means that the collection of net names running along the bus are predefined within the bus. Only those nets can be used when connecting to the bus, whereas, an Open Bus can carry any net.

How to find this function?

To make the use of Bus function easy we added a new shortcut icon in the Schematic view. Aternatively the Bus function is available under CTRL+B shortcut.


How to Add a Bus?

If you are adding another bus of the same type as one already added in the design, select the bus in the design first before following the procedure below. This will ensure the new bus will have the same width and set of net names as the selected one.

From the Add menu select the Bus option, or use the Bus icon from the Schematics Toolbar.

  1. If you have not already done so, set up the Working Grid (refer to Help>Contents>Search>Grids). The corners of the bus shape will be gridded using a step size relative to the working grid. Use the 'Ctrl + G' shortcut key at any point to change the step size relative to the working grid.
  2. Click to define the start position of the bus. Some dynamic segments will be drawn from the start position to the moving cursor. If a bus was not pre-selected, the line width is taken from the style used when you were last in this option. Whatever is defined here will be used for the initial bus outline. To change this at any point during the adding of the bus, right click to use the shortcut menu to change the style (width).
  3. Move the cursor to position the next corner, the gridded position of the moving corner will be shown on the Status Bar (refer to Help>Contents>Search>Status Bar).
  4. Right click to use the shortcut menu options to modify the appearance of the segments being inserted. It is recommended that you use the Segment Mode Mitre to add the mitred corners to the bus shape. See Editing Shape Segments (refer to Help>Contents>Search>Editing Shape Segments) for more details on these shortcut options.
  5. Click to add a corner to the bus. The dynamic segments will become a fixed part of the bus and some new dynamic segments will be added for you to define the next corner. Each subsequent click will add another corner.
  6. To finish the bus, double-click the left mouse button.

At any point, if you want to exit or make a mistake and need to start again, press the ESC key on the keyboard.

More information

For further information on how to define a Closed Bus, Multiple Busses, Adding connections to Busses, Displaying Bus Net Names and more, please refer to Help>Contents>Search>Add Bus:


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