Track not locking to same net pad in Altium

Question

I use interactive routing with Altium to route components using Ctrl+W. This normally works well, but I have some castellated holes that are not in the schematic (I created them in the PCB file directly). They are set to the nets they are intended to, but I cannot interactively route to them. The tracks won't lock to the castellated pads:

I have to do it the other way around, from them to the other components like so:

This is a concern because it starts the tracks from the center of the pad, where as I could lock them from their lower edge if I could connect with the interactive routing as seen in first image.

Is there a setting somewhere that could let me connect to pads like these that are not in the schematics?

Answer 1

Here are some things you can try:

1. Sometimes this behavior (not connecting to same-net objects) is inhibited by a clearance issue. Try momentarily setting Routing Options > Conflict Resolution to "Ignore Obstacles":

   

   This will eliminate clearance rules as the reason it is not allowing the connection. (If this solves the issue, then you need to check your design rules to see if any are affecting the tracks/pads in question.)

2. There could be a track fragment hiding in the pad of a different net. Set the selection filter to track only:

   

   And select everything over and around the pads that are giving you the problem. If you see any pieces of track within the pad, delete them as they might be conflicting.

   For example, here's a pic showing a track fragment where the visible pieces exiting the pad were removed, but the remaining piece is still superimposed over the pad, and has a different net:

   

3. If your castellated holes are on the PCB edge, it could be a Board Outline Clearance design rule preventing the track from routing to the pad. Even if the pad is not in the schematic, Altium should route to it if it is the same net. Try A) disabling any Board Outline Clearance rules if they exist, or B) move the castellated pad to another location (temporarily) to see if routing to it is allowed.