Abstract: The invention proposes a portable modular wirefree identification signal transmitter for actuating, in particular for opening and/or closing, access points such as doors, gates, etc., remotely, having a housing which has at least one externally accessible receptacle for accommodating a respective exchangeable system module, an identification code of a wirefree access control system being stored in the system module. A control device is arranged in the housing and is configured to read the identification code of a system module which is accommodated. At least one transmitter device is permanently arranged in the housing and is adapted to transmit the identification code of a system module which is accommodated, to a reader device assigned to an access point. Depending on the system module accommodated, the identification signal transmitter can be used for opening and closing access points with different wirefree access control technologies.