Working with Grids & Guides

The PCB editor is a grid-based design environment - design objects are placed on what is referred to as the placement, or snap grid. Multiple snap grids can be defined, and these can be restricted to a specified area if required. Snap grids are prioritized, with the highest priority grid available at the current location, being applied automatically. Snap grids can also be restricted to Components or Non-Components.

Also, snap guides can be freely placed and provide a handy visual cue for object alignment.

This page describes how to configure snap grids and snap guides in your PCB document.

User-Definable Grids

Any number of user-defined grids can be configured for the design space with all grid management performed from within the Grid Manager region of the Properties panel (accessed when there are no design objects currently selected in the design space). Use the controls available to define custom local grids by which to place design objects - especially components - with greater precision.

The Grid Manager region of the Properties panel is command central for defining and organizing the grids for use with your board.

Grid Types

The software supports the creation of the following two custom grid types:

• Cartesian Grid - create a new grid of this type using the Add Cartesian Grid command (available from the  button, as described earlier). A new grid entry will appear in the list, initially with the default name New Cartesian Grid. To edit the grid, double-click on its entry or select its entry and click the  button. The Cartesian Grid Editor dialog will open presenting options with which to define the grid.

  Example Cartesian grid definition, using the Cartesian Grid Editor dialog, and resulting appearance in the design space.

  Options and Controls of the Cartesian Grid Editor Dialog

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  For the default global snap grid, only the Settings, Steps and Display regions will be presented in the dialog.

  Settings

  • Name – enter a meaningful name. For example, you might name the grid using a format that reflects its purpose (e.g., Grid for Component-Side Memory).
  • Unit – specifies the measurement units used for the grid either Imperial or Metric.
  • Rotation – specifies whether the grid is to be rotated (about the specified origin point) and by how much.

  Steps

  • Step X – the distance between grid lines in the X plane. Enter the required step size directly or select from a range of common sizes available in the associated drop-down.
  • Step Y – the distance between grid lines in the Y plane. Enter the required step size directly or select from a range of common sizes available in the associated drop-down.

  By default, the two fields are linked as indicated by the continuous chain depicted on the button to the right of the fields – . In this state, whatever you specify for the Step X field will be copied and used for the Step Y field. To break this link and enter step sizes individually, click the chain link. The link will display a broken chain – – and the Step Y field will be available for editing.

  The following controls also are available that allow you to define the X and/or Y step sizes directly from within the PCB design space. In each case, you will be taken to the design space to specify two 'calculating' locations and the resulting step size will be calculated accordingly.

  • Set Step X in PCB View – the resulting size is taken as the hypotenuse of the triangle formed by the chosen points in the design space.
  • Set Step Y in PCB View – the resulting size is taken as the hypotenuse of the triangle formed by the chosen points in the design space.
  • Set Step X from Delta X – the resulting size is taken using just the difference in the X coordinate.
  • Set Step Y from Delta Y – the resulting size is taken using just the difference in the Y coordinate.
  • Set Both Steps from Delta – the resulting sizes are taken using just the differences in the X and Y coordinates.

  Note that when Step Y is following Step X (with the chain "linked"), only the Set Step X in PCB View and Set Step X from Delta X controls are available.

  Origin

  • Show Origin – enable to show an origin marker in the design space.
  • Origin X – specifies the X coordinate for the center point of the grid in the design space.
  • Origin Y – specifies the Y coordinate for the center point of the grid in the design space.
  • Set Origin in PCB View – click to be taken to the PCB design space, in which you can click to define the centerpoint for the grid's origin. The resulting coordinate values will be loaded into the Origin X and Origin Y fields.

  Display

  • Fine – use the associated drop-down to define the markers used for the fine-level display of the grid in the design space, either Lines, Dots, or Do Not Draw. Choose Do Not Draw if you do not want to use the fine-level display grid. The step size used for the markers is that defined in the Steps region. Click on the associated color swatch to access the standard Choose Color dialog from where you can specify the color to be used for the fine-level display grid in the design space. You also can reset the color back to its default using the Reset to Default button.
  • Coarse – use the associated drop-down to define the markers used for the coarse-level display of the grid in the design space, either Lines, Dots, or Do Not Draw. Choose Do Not Draw if you do not want to use the coarse-level display grid. The coarse-level display grid is the fine-level display grid with an increased step size, in accordance with the entry selected in the Multiplier field. Click on the associated color swatch to access the standard Choose Color dialog from where you can specify the color to be used for the coarse-level display grid in the design space. You are free to choose a completely different color to that used for the fine-level display grid. You also can quickly lighten or darken the shade of the color currently used for the fine-level display grid by clicking the Lighter or Darker buttons.

  The default display colors that are assigned to the Fine and Coarse display grids when the Reset to Default button is clicked are defined in the System Colors region of the View Configuration panel (shortcut L).

  • Multiplier – use this field to specify the required multiple of the grid's step size, either 2x Grid Step, 5x Grid Step, or 10x Grid Step.

  Extents

  • Width – use this field to define the width of one quadrant of the grid.
  • Height – use this field to define the height of one quadrant of the grid.

  By default, the two fields are linked, as indicated by the continuous chain depicted on the button to the right of the fields – . In this state, whatever you specify for the Width field will be copied and used for the Height field. To break this link and enter values individually, click this chain link. The button will now depict a broken chain – – and the Height field will be available for editing.

  Controls are also available that allow you to define the width and/or height directly from within the PCB design space. In each case, you will be taken to the design space to specify two 'calculating' locations, and the resulting width and/or height will be calculated accordingly.

  • Set Width in PCB View – the resulting width is taken using just the difference in the X coordinate between the chosen points in the design space.
  • Set Height in PCB View – the resulting height is taken using just the difference in the Y coordinate between the chosen points in the design space.
  • Set Width and Height in PCB View – the resulting width and height are taken using just the differences in the X and Y coordinates.

  Note that when Height is following Width (chain is linked), only the Set Width in PCB View control is available.

  Quadrants

  Use this region to specify which quadrants the grid is to occupy. The grid area is the same for all enabled quadrants as defined by the setting for Width and Height in the Extents region of the dialog.

  
  Example of using the Quadrants region options. Note that only 1, 2, and 4 quadrants are enabled for use, and the resulted grid occupies only these quadrants relative to the grid origin.

• Polar Grid - create a new grid of this type using the Add Polar Grid command (available from the  button, as described earlier). A new grid entry will appear in the list, initially with the default name New Polar Grid. To edit the grid, double-click on its entry or select its entry then click the  button. The Polar Grid Editor dialog will open presenting options with which to define the grid.

  Example Polar grid definition using the Polar Grid Editor dialog and resulting appearance in the design space.

  Options and Controls of the Polar Grid Editor Dialog

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  Settings

  • Name - use this field to give the polar grid a meaningful name. For example, you might name the grid using a format that reflects its purpose (e.g., Grid for Component-Side Memory).
  • Unit - use this field to specify the measurement units used for the grid: Imperial or Metric.

  Steps

  • Angular Step - use this field to define the distance, in degrees, between the angular grid lines. This value is used to equally space the angular grid lines over the defined angular range.
  • Radial Step - use this field to define the distance between the radial grid lines. Type the required step size directly or select from a range of common sizes available in the associated drop-down list.
  • Set Radial Step in PCB View - click to define the radial step directly from within the PCB design space. You will be taken to the design space to specify two 'calculating' locations – the resulting step size is taken as the hypotenuse of the triangle formed by the chosen points in the design space.

  Origin

  • Origin X - use this field to specify the X coordinate for the center point of the grid in the design space.
  • Origin Y - use this field to specify the Y coordinate for the center point of the grid in the design space.
  • Set Origin in PCB View - click this control to be taken to the PCB design space in which you can click to define the centerpoint for the grid's origin. The resulting coordinate values will be loaded into the Origin X and Origin Y fields.

  Display

  • Fine - use the associated drop-down to define the markers used for the fine-level display of the grid in the design space, either Lines, Dots, or Do Not Draw. The step size used for the markers is that defined in the Steps region. Click on the associated color swatch to access the standard Choose Color dialog in which you can specify the color to be used for the fine-level display grid in the design space. If you do not want to use the coarse-level display grid, choose the Do Not Draw option. You also can reset the color back to its default using the Reset to Default link.
  • Coarse - use the associated drop-down to define the markers used for the coarse-level display of the grid in the design space, either Lines, Dots, or Do Not Draw. The coarse-level display grid is the fine-level display grid with an increased step size in accordance with the entry selected in the Multiplier field. If you do not want to use the coarse-level display grid, choose the Do Not Draw option. Click on the associated color swatch to access the standard Choose Color dialog in which you can specify the color to be used for the coarse-level display grid in the design space. You are free to choose a completely different color to that used for the fine-level display grid. Alternatively, you can quickly employ a lighter or darker shade of the color currently used for the coarse-level display grid using the available Lighter or Darker links. You also can reset the color back to its default using the Reset to Default link.
  • Multiplier - use this field to specify the required multiple of the grid's step size, either 2x Grid Step, 5x Grid Step, or 10x Grid Step.

  The default display colors that are assigned to Fine and Coarse display grids when the Reset to Default link is clicked are defined in the General Settings region on the View Options tab of the View Configuration panel.

  Angular Range

  • Start Angle - use this field to configure at which angle the polar grid begins.
  • End Angle - use this field to configure at which angle the polar grid ends.

  If the start angle and end angle are set to the same number, the dialog will automatically update to Start Angle 00.000 and End Angle 360.000. The polar grid will display as a full 360°.

  Radial Range

  • Min - use this field to set the minimum diameter of the polar grid.
  • Max - use this field to set the maximum diameter of the polar grid.

  The diameters of the Radial Range are measured from the origin point out and set the radial extents of the grid.

Default Snap Grid

A default snap grid is defined for the board, named Global Board Snap Grid. This is the grid that is used for object placement and movement in any area of the board not covered by a dedicated local grid.

Global Board Snap Grid - used in any area of the board where a custom local grid has not been defined.

The default grid is a Cartesian-type grid. The step size and/or display for the grid can be modified, but the grid cannot be renamed, disabled, or deleted.

Defining the Purpose of a Grid

A local grid can be used in a variety of situations:

• In the placement of non-component objects only.
• In the placement of component objects only.
• In the placement of both non-component and component objects.

Definition of how a grid can be used (its purpose or application) is performed using the Comp and Non Comp options associated with that grid's entry in the Grid Manager region of the Properties panel, in accordance with the following table:

Use the Comp and Non Comp options to determine local grid application.

Defining the Grid Display

For any custom grid you define, as well as the Global Board Snap Grid, options are provided to control how the grid is presented visually in the design space. Two levels can be defined:

• Fine - the fine-level display grid is for when you are more zoomed-in. The grid markers for this level of grid display follow directly the defined step sizes for the grid.
• Coarse - the optional coarse-level display grid comes into play as you zoom out. The grid markers for this level of grid display are based on a specified multiple of the defined step sizes.

Example Cartesian grid with fine- and coarse-level display grids presented in the design space. Left: Fine-level displayed using dots, coarse-level using Lines. Right: Both fine- and coarse-level grids displayed using Lines.

Nesting and Grid Priority

The local grids you define in the Grid Manager region of the Properties panel can be freely stacked within the board area. By specifying origin coordinates accordingly, grids can be overlapped, creating a nested hierarchy of grids with which to fine-tune the placement of design objects as you layout your board.

Grid contention - which grid in an overlapping stackup of grids should a design object snap to - is resolved using a priority system. Each local placement grid you create and define is given a numbered priority. By default, each new grid is given the highest priority of 1, with all existing grids moved down in priority accordingly.

In the design space, priority is distinguished by drawing order. The highest priority grid (priority 1) will be drawn in front of all other grids, then the grid with priority level 2, and so on, down to the default Global Board Snap Grid, which is drawn behind all other custom grids.

An example of three nested Polar grids. The Yellow Polar Grid has the highest priority and appears on top. The Red Polar Grid is the next priority, appearing behind the yellow grid but in front of the aqua grid. The default grid appears behind all of these grids, as all custom grids take precedence over it in the priority stakes.

Disabling a Grid

There may be occasions where a grid is not needed while placing or moving a particular design object. Rather than deleting the grid (since it may be needed again later in the same or different area of the board), it can be 'hidden' in the design space. This can be achieved by disabling the grid's associated Comp and Non Comp attributes in the Grid Manager region of the Properties panel.

Disable a local grid to effectively hide it, therefore preventing objects from snapping to it. Using the nested grids example, the Red Polar grid has been disabled. As the grid has not been deleted, you can re-enable and use it again when needed without having to redefine it!

Deleting a Grid

Custom grids can be deleted by selecting their corresponding entry in the Grid Manager region of the Properties panel then clicking the  button. You will be asked to confirm the deletion. Click Yes to do so.

Snap Guides

Snap Guides are special objects that are manually placed specifically for the purpose of driving the cursor-snap on a certain axis or point - assisting in object/component placement. They can also serve as a visual indicator for general layout or alignment purposes. The following types of snap guides are supported:

• Linear Guide - a line-style guide that can be horizontal, vertical or +/- 45 Degrees.
• Point Guide - a point-style guide offering finer control over object placement. It is simply a hotspot that is manually marked within the confines of a defined grid.

Any number of snap guides can be defined for the design space with controls for placement and management available from the Guide Manager region of the Properties panel (accessed when there are no design objects currently selected in the design space). While controls are available for adding new snap guides from within this region (from the  button), it is far easier to visually add them (from the  button) directly in the design space then fine-tune them as required.

Snap Guides can also be placed using commands available from the Place » Work Guides sub-menu.

The Guide Manager region of the Properties panel is command central for managing visual placement guides for use in the design space. These are examples of the various Snap Guides available to assist object placement.

During an interactive process such as placing or moving, the cursor will snap to a placed Linear Guide at the point where that guide intersects a defined grid. Using a Linear Guide, objects can quickly be aligned by dragging them until they 'snap' against the guideline. For a Point Guide, the hotspot for the object being moved will 'snap' to the guide when it passes into close proximity with it.

Disabling a Guide

There may be occasions where a snap guide is not needed while placing or moving a particular design object. Rather than deleting the guide (since it may be needed again later in the same or different area of the board), it can be 'hidden' in the design space. This can be achieved by disabling the guide's associated Enabled attribute in the Guide Manager region of the Properties panel.

Disable a snap guide to effectively hide it, therefore preventing objects from snapping to it. In this image, the +45 and -45 guides have been disabled. As the guides have not been deleted, you can re-enable and use them again when needed without having to redefine them!

Deleting a Guide

To delete a snap guide, select its entry in the Guide Manager region of the Properties panel then click the  button. You will be asked to confirm the deletion. Click Yes to do so.