Beckhoff EL34 Series Documentation page 128

Commissioning
Fig. 144: Illegally exceeding the E-Bus current
From TwinCAT 2.11 and above, a warning message "E-Bus Power of Terminal..." is output in the logger
window when such a configuration is activated:
Fig. 145: Warning message for exceeding E-Bus current
Caution! Malfunction possible!
The same ground potential must be used for the E-Bus supply of all EtherCAT terminals in a terminal block!
128
NOTE
Version: 1.5 EL34xx