The invention relates to a method for transmitting a process map of a control or automation system via a gateway device (20), which comprises at least one first functional unit (21), to which a higher-ranking control unit is connected via a first communications link (1) based on a primary field bus protocol, and at least one second functional unit (22), to which at least one field device (30) is connected via a second communications link (2) based on a secondary field bus protocol. Process variables provided by the field devices (30) are transmitted as process data objects (PDO1), (PDO2) based on the secondary field bus protocol (2) into the second functional unit (22) of the gateway device (20), which operates as a master task, as telegrams. The process data objects (PDO1), (PDO2), which are present as digital signals, are assigned corresponding registers (Bool1), (Bool2), (Bool3), which are present in binary form. The process data objects (PDO1), (PDO2) present as analog objects are assigned corresponding addresses in the integer format (INT16). The binary signals (Bool1), (Bool2), (Bool3) stored in the corresponding registers and the analog signals present in the integer format (INT16) are transmitted into the first functional unit (21) that operates as a gateway task in such a manner that the number of binary signals is reduced by packing the binary signals into data blocks of eight bits each, which then respectively form a byte and are translated into corresponding telegrams that can be processed by the primary field bus protocol (1) which, together with the analog signals present in the integer format (INT 16), are transmitted to the higher-ranking control unit on the basis of the primary field bus protocol (1).