The job of the EL3142-0010 analog input terminal is to supply power to measuring transducers located in the field, and to transmit analog measurement signals with electrical isolation to the automation device. The voltage for the sensors is supplied to the terminals via the power contacts. The power contacts can optionally be supplied with operating voltage in the standard way or via a supply terminal (EL9xxx) with electrical isolation. The input electronics is independent of the supply voltage of the power contacts. The 0 V power contact is the reference potential for the inputs. The EtherCAT Terminal indicates its signal state by means of light emitting diodes.

https://www.beckhoff.com/vi-vn/products/i-o/ethercat-terminals/el3xxx-analog-input/el3142-0010.html