If you make a unique train signal that is not taken from a actual signal; like one with a triangular face; then yes you would own a copyright in that unique interpretation of a signal design.
Of course who would want to pay for that!.
Using someone else's software to design a signal does not give the software owner any rights at all to your signal design. That would be like saying that a camera manufacturer owns a copyright in all pictures taken by one of its cameras.
The medium does not control the message... ask FaceBook.
However, to have a copyright the message must be in a medium.
