BECKHOFF EP9128 - Manual (Page 19)

Basic functioin principles
Fig. 14: Physical arrangement of the EP9128's ports
Accordingly, 3 devices are displayed in the TwinCAT System Manager:
Fig. 15: Slaves in the TwinCAT System Manager
Please note:
• port 1 is always the input for the EtherCAT traffic in the EP9128
• the other ports (2 to 7) should be used as outputs
• it is not permitted to delete sub devices once the EP9128 has been configured
For differentiation see also EEPROM Update [ } 41].
EP9128 19 Version 2.1.0