The MicroLok II VitalNet CPU, a Positive Train Control (PTC) central processing unit, provides Vital PTC compatibility that enables Ansaldo STS USA's customers to leverage existing and new MicroLok II wayside signaling investments in concert with PTC implementation. An existing MicroLok II CPU board is easily exchanged with a VitalNet CPU board, providing a PTC-ready interface. The upgrade does not affect the existing MicroLok II interlocking logic and does not require a re-test of the application logic in most situations. The VitalNet CPU boards are available for order and delivery to customers in volume quantities.