Setting units of measurement

In Layout, you can set numeric data to display in mils, inches, microns, millimeters, or centimeters. You can change these values as needed (for example, you can route the board in inches or mils, then confirm pad locations within footprints in millimeters).

To set measurement units

1 Open your board in Layout.

2 From the Options menu, choose System Settings. The System Settings dialog box appears.

3 Select mils, inches, microns, millimeters, or centimeters.

4 Choose the OK button.

Setting system grids

Using the System Settings dialog box, you can set five distinct grid settings. The grid values that you assign determine the resolution of the pointer location coordinates given in the status bar in the lower left corner. For example, if the obstacle tool is selected and the Place grid is set to 100 mils, the coordinates that display are accurate to 100 mils. Grid values are in user-specified units that you set in the Display Units group box in the System Settings dialog box. If you want to use fractions in your grid values, enter a space character following the integer and use a forward slash as the division character (for example, 8 1/3). You can also use decimals for rational numbers.

Visible grid

Assigns a display grid based on the X and Y coordinates (for example, if you’re using mils, a setting of 200 would place a grid dot at every 200 mils).

Detail grid

Assigns a drawing grid (for lines and text) based on the X and Y coordinates.

Place grid

Assigns a component placement grid based on the X and Y coordinates. For greatest routing efficiency, this value needs to be a multiple of the routing grid. The datum, or origin, of footprints is constrained to this grid. Setting system grids

Routing grid

Assigns a grid used for routing (see the routing grid chart below for suggested settings).

Via grid

Assigns a grid upon which you or the router can place vias.