By defining the explicit device ID via address switch, the EtherCAT Fieldbus Coupler from WAGO always retains its set node address, regardless of its position on the EtherCAT bus. This method of address allocation is less restrictive than other more simple methods in which all bus nodes are numbered consecutively according to their location (order) on the fieldbus: Changes within network configuration are not necessary because address changes no longer occur via rewiring. The EtherCAT Fieldbus Coupler (750-354/000-001) connects EtherCAT applications to the modular WAGO-I/O-SYSTEM. The system's fieldbus coupler automatically identifies the connected I/O modules and generates data for the relevant application. Analog and specialty module data are sent via words; digital data is sent bit by bit. Although the EtherCAT telegram passes through the device, the only data taken from the telegram is that for the fieldbus coupler. The coupler, in turn, adds the required process data. Both line-in and line-out RJ-45 connectors are located on the front of the coupler, providing easy configuration of line structures.