The EL9410 power supply terminal is used to refresh the E-bus. Data is exchanged between the coupler and the EtherCAT terminal over the E-bus. Each terminal draws a certain amount of current from the E-bus. This current is fed into the E-bus by the relevant couplers power supply unit. In configurations with a large number of terminals it is possible to use the EL9410 in order to supply an extra 2 A to the E-bus. The EL9410 has a diagnostic function which is displayed by LED and on the process image.