Use this to automatically display the clearance around static items during some interactive operations. Generally it is used if the operation involves editing a simple single item on an electrical layer. One example is during the manual insertion of tracks.
This clearance shows how close the item can be placed to another without violating it.
How To Use Display Clearances
Use the Online DRC tab on Options dialog, found on the Tools menu. Enable Show Design Rule Clearance and set the required clearance mode.
On All Items - All the electrical items that are visible on the same layer as the item being edited will have the clearance drawn around them.
Within Set Distance - (Normal mode) When the item being edited comes within the entered distance of another static item the static item will have it’s clearance drawn around it.
Within Grid Steps - When the item being edited comes within the entered number of grid steps of another static item, the static item will have it’s clearance drawn around it.
Now that the mode is set, use an interactive operation like Edit Track. Right click the mouse to show the shortcut menu to make sure the Display Clearances option is checked. As you move the track near other tracks on the same layer, they will have the Track to Track clearance draw around them to warn you how close you can get.
How Display Clearances Works
To illustrate how this works, we will use the Add Track option, and the Clearance mode will be Within Set Distance
Move the track down close to the pad.
 | As the dynamic track comes close to an obstacle item, the obstacle is outlined in the ‘Within Clearance’ warning colour (set to Orange by default). The clearance shown is set to the size of the allowed spacing between the static obstacle and the item being interactively edited. So here the obstacle is a pad, so the clearance is set to the Track to Pad design rule spacing. |
Ignore the warning and move the track lower, closer to the pad.
 | As the track continues to draw closer to the obstacle pad, it violates the Track to Pad design rule spacing rule. The clearance will change colour to the ‘Online DRC’ warning colour (set to Red by default). This shows that if the track is dropped at this point then a Design Rule Error will occur between the track and the pad. If Online DRC is enabled using Continuous Mode, this will never occur as you will prevented from moving within this gap. If Online DRC is enabled, but using On Drop Mode instead of Continuous, then an Online DRC Error will be given as you finish the track. |
The two clearance colours can be set up in the Colours - Highlights dialog.
Related Topics
Design Rule Check | Colours - Highlights | Edit Track | Colours - Highlights | Online DRC | Technology - Spacing Rules