An elevator comprising: a communication bus; and an apparatus, the apparatus further comprising: at least one bus connection configured to connect to a communication bus; a communication microcontroller associated with the bus connection to control the communication bus; at least one connection configured to connect safety non-critical elevator components (14,15); and at least one microcontroller (16,17) configured to communicate with at least one safety critical elevator component (18a, 18b), wherein at least one of microcontroller (16,17) of said at least one microcontroller (16,17) is coupled with said communication microcontroller, and wherein the communication microcontroller is configured to generate a data packet comprising an identification code to indicate whether the data packet comprises safety critical information or not and the communication microcontroller being further configured to send to the data packet to the communication bus; wherein the apparatus is connected to an elevator safety module and an elevator operation control using said bus (11, 51); characterized in that the elevator safety module is further configured to read the data packet from the communication bus and, if the data packet comprises safety critical information, to transfer the safety critical information to at least one safety processing unit of the elevator safety module, and in that the safety processing unit is configured to perform a safety shutdown of the elevator if the safety critical information received fulfills safety shutdown criteria. a communication bus; and an apparatus, the apparatus further comprising: at least one bus connection configured to connect to a communication bus; a communication microcontroller associated with the bus connection to control the communication bus; at least one connection configured to connect safety non-critical elevator components (14,15); and at least one microcontroller (16,17) configured to communicate with at least one safety critical elevator component (18a, 18b), wherein at least one of microcontroller (16,17) of said at least one microcontroller (16,17) is coupled with said communication microcontroller, and wherein the communication microcontroller is configured to generate a data packet comprising an identification code to indicate whether the data packet comprises safety critical information or not and the communication microcontroller being further configured to send to the data packet to the communication bus; wherein the apparatus is connected to an elevator safety module and an elevator operation control using said bus (11, 51); characterized in that the elevator safety module is further configured to read the data packet from the communication bus and, if the data packet comprises safety critical information, to transfer the safety critical information to at least one safety processing unit of the elevator safety module, and in that the safety processing unit is configured to perform a safety shutdown of the elevator if the safety critical information received fulfills safety shutdown criteria. at least one bus connection configured to connect to a communication bus; a communication microcontroller associated with the bus connection to control the communication bus; at least one connection configured to connect safety non-critical elevator components (14,15); and at least one microcontroller (16,17) configured to communicate with at least one safety critical elevator component (18a, 18b), wherein at least one of microcontroller (16,17) of said at least one microcontroller (16,17) is coupled with said communication microcontroller, and wherein the communication microcontroller is configured to generate a data packet comprising an identification code to indicate whether the data packet comprises safety critical information or not and the communication microcontroller being further configured to send to the data packet to the communication bus; wherein the apparatus is connected to an elevator safety module and an elevator operation control using said bus (11, 51); characterized in that the elevator safety module is further configured to read the data packet from the communication bus and, if the data packet comprises safety critical information, to transfer the safety critical information to at least one safety processing unit of the elevator safety module, and in that the safety processing unit is configured to perform a safety shutdown of the elevator if the safety critical information received fulfills safety shutdown criteria.