You may try to add SCAN_LIMIT in your c_scan mode list to find those
entities with ENABLE_SCAN is on.

Code:

---

function scanEvent()
{
   if (event_type == event_scan)
   {
	my.enable_scan = off;  // scanner will ignore me. But then again
                               // you need to find a way to re-enable it again
   }
}

action scanEntity
{
  my.enable_scan = on;
  my.event = scanEvent;
}

---