Grids

Grids allow you to define the points or steps to which items will “snap” when they are placed. The Grids dialog allows you to add or change the settings for any of the grids in the design.

Use the Interactive Grid tab to define which grid is used for which item type during interactive operations. The Tools Grid tab to define which grid is used for which item type during automatic operations. In it’s simplest form, you may want to set all grids to be the same. Use the relative grid feature to ensure that grids are defined as multiples of a more basic grid. For example, the Component Grid could be a multiple of the Track Grid.

All Grids are stored as a facet of your design but are also part of the Technology file

Shortcuts

Default Keys: Alt+G

Default Menu: Setup

Command: Grids

Locating this option

Available from: Setup menu > Grids option, or

Setup menu > Technology > Grids

How to Use This Dialog

At it’s simplest, using this dialog is as easy as pressing the shortcut key, typing the new grid value, and pressing Enter. The grid most relevant grid to the currently selected items will be selected (i.e. the grid which is the appropriate interactive grid for the selected items). The same result can be achieved using the Grid Step dialog. However, Grids have more capabilities than this, including definable origins, different X and Y steps, and scaling. These features are described below.

Grid

Choose the grid you wish to examine or modify.

New; allows you to create a new Grid. Delete; enables the currently selected Grid to be deleted. You can only delete a grid which is not Used, which means it is not currently an Interactive or Tools Grid, or referenced as a relative grid.

Relative

Selecting a Relative grid allows you to define one grid to take its step value from another. For example, you might set the Via grid to be relative to the Track grid, with a Multiplier of 4. This would ensure that the Via grid is always four times the size of the Track grid even if you change the actual step value of the Track grid.

Step

This section of the dialog defines how the grid points are spaced across the design area. The simplest kind of grid has the same Basic Step between successive grid points, as shown in figure 1 below.

Sometimes it is useful to be able to make the grid steps smaller for a specific operation (perhaps to position several items close together) without losing the original basic step. Figure 2 below shows an example using a Divisor of 4, making each grid position just 0.25mm where the original Basic Step is 1.0mm.

Using a Divisor is a good way to produce a fractional grid, for example you may want to route two tracks through a 100 thou gap. You can achieve this by creating a grid with a basic step of 100 and a Divisor of 3. There is no accumulated rounding error using this method.

It is also possible to set up grids with different X and Y values, as shown in the picture above. Checking “Different X & Y” will display the additional controls needed to set up the Y grid values. These can be used to set the same grid combinations as for a normal “symmetrical ” grid.

Figure 3 below shows a simple asymmetrical grid, with the Y grid step 50% larger than the X step. Figure 4 is more complex, with a sub-divided grid in X and a simple grid in Y.

Origin

The origin of any grid can be changed to a specific value. The default is 0,0 which places the grid origin at the coordinate origin. Grid steps are measured from the grid origin, so for example if the grid step is 5mm, and the grid origin is at 2mm, the first grid step after the origin is at 7mm.

If the grid is not defined relative to another grid, you can set the origin using the buttons to the right. These allow you to set the origin to specific points in the design, such as the centre of the board outline, the Coordinate System Origin, the Relative Origin or the Symbol Origin (when editing a symbol). A grid origin already set to one of these positions will be indicated by the appropriate button text being emphasised. Setting the grid origin is particularly important for Polar grids.

A grid origin may be ‘locked’ to a particular origin in a design by checking the Lock option next to the appropriate button. Once locked, grid origin will automatically track any change in position of that type of origin in the design.

If you are working with multiple grids that require the same origin settings, you can use the Apply Origin Settings To All Grids button. This allows the origin settings from the chosen grid to be applied across all other grids in a design when this button is selected.

The use of Apply Origin Settings To All Grids is also a great way to reset all origins back to a desired grid default. For example, simply enabling the Apply Origin Settings To All Grids check box then clicking Coordinate Origin will set all the grids to have a coordinate origin of (0,0) once OK or Apply is clicked.

If the grid is defined relative to another grid, some alternative options are available. Here we can see the origin coordinates of the grid which this grid is relative to. However, now they are greyed out to indicate that they cannot be altered in this context. The boxes to the right of these represent any offset we may wish to apply on top of the original, relative, origin. To the far right we can see the final sum of our original origin along with said offset, thereby representing the ultimate origin of the grid.

Polar

Polar grids are particularly useful for placing components on a circular board. Whilst moving a component on a polar grid, use the Auto Rotate command to rotate the component relative to its position on the grid.

For a polar grid, check the Polar Grid box. You should then define the number of radial steps. For example 8 radial steps would give one every 45 degrees, radiating from the origin. The concentric step is the gap between each concentric circle around the origin. The origin angle is the angle of the first radial, this effectively rotates the whole grid about the origin. For relative polar grids, only the grid origin position is relative.

Displayable

Any grid in the design can be displayed on the screen. By checking the “Displayable” button, the chosen grid becomes capable of being displayed. Whether it is actually displayed is also dependent on whether grids are currently being displayed, as indicated by the Grids Displayed setting described below.

There is an exception to this, see Draw Interactive Grid Only below.

Once a grid is set as Displayed, the colour can be chosen. The grid can also be displayed either as dots, lines, small horizontal crosses or diagonal (X) crosses. The size of crosses are related to the size of the grid. Note that for polar grids, the horizontal and diagonal crosses appear the same. The display interval can also be set, to display perhaps only every 10th grid step to avoid cluttering the screen with too many grid points.

By careful choice of colours and display interval, it is possible to set up several grids as displayed to help you in placing items on the design. The example below shows the Component grid as dark blue lines, and and every 4th step of the basic Working grid as red dots.

Global Grid Settings

As well as being able to set whether or not individual grids are displayable, by using the list labelled Display it is possible to select how grids are to be displayed generally. There are four possible options:

• No Grids: means that no grids will be displayed, no matter what.

• Grids: means that all grids that are set as Displayable will be displayed.

• Only Interactive Grids: means that any grid specified for an interactive operation will be displayed exclusively (even if the particular grid is not set as Displayable). When no interactive operation is being used the general Interactive Grid is displayed

  Note, With this option enabled if you use an explicit grid step, i.e. by typing “G 10” in an interactive mode, the colour and style of the grid will be taken from the working grid.

• Only Interactive Grids During Editing: provides alternative behaviour to above for when not currently using an interactive operation, i.e. in Select Mode. When this option is chosen, Select Mode will display all grids that are set as Displayable rather than the general Interactive Grid.

Note: It is also possible to toggle whether grids are displayed, at any time from outside this dialog, using the shortcut key assigned to the “Display Grids (On/Off)” command, which by default is Ctrl+G.

Note: There is also a Design Option to choose whether to draw the grids before or after the actual design items.

Units

The Units button allows you to locally switch between Metric and Imperial units whilst in this dialog. Once the dialog is closed, the units revert back to the original design units. If switching to different units to the design units, the value typed will be converted when you next enter this page.

Related Topics

Technology Overview | Grid Steps | Interactive Grid | Tools Grid | Design Settings - Coordinate System