EtherCAT mapping in the Modbus process image
The Modbus service page shows in which Modbus process image (offset) the EtherCAT Terminals that are used are located. The page also indicates where the terminals are located in the Modbus process image and which Modbus function can be used to access them.
Information on how to interpret the data of the individual EtherCAT Terminals can be found in the terminal-specific documentation.