Do I require Ethernet comms module PM8ECC for Ethernet comms?
The PM800 series meters use Modbus RTU protocol as standardto communicate through its RS-485 serial communications port. So yes you will need the PM8ECC to communicate via Ethernet.
The PM8ECC provides Ethernet communications capability and Ethernet Gateway functionality to the device. The gateway uses Modbus TCP/IP protocol to communicate on the Ethernet port and Modbus RTU on the serial port.