Division 4.2.6.1 Interface between ETCS and STM

The Specific Transmission Module (STM) allows ETCS on-board to operate on lines fitted with Class B ATP/ATC systems.

The interface between the On-board ETCS functionality and the STMs for Class B ATP/ATC systems is defined in Annex A, index 4, 8, 15, 25, 26, 49. Annex A, Index 45 specifies the K interface and index 46 the G interface. Implementation of the Interface ‘K’ is optional, but if done it must be in accordance with Annex A, Index 45. Furthermore, if Interface ‘K’ is implemented, the On-board transmission channel functionality shall be able to handle the properties of Annex A, Index 46.