Before you can autoroute cables, you must prepare a path for them. With the Gather edge for path command, you can route the channel along any 2D or 3D geometry, including model edges and existing, manually-routed cables.
To route a channel on edges,
1. Click Channel and then, in the Modify group, click the arrow next to Add edge.
2. Click Gather edge for path. The Add Edge as Segment dialog box opens.
3. Select an edge in the viewport. Hold the Shift key to select multiple edges, or click Next to select another edge.
◦ Click Keep Edge to retain 2D geometry if routing the channel along a wire edge.
Add edge.
Gather edge for path. The Add Edge as Segment dialog box opens.
to complete the operation.