Hello,
very great to have found Your blog. I use the same energy meter dds238 in a Home Assistant, but there is no way to get data from it.
I have a different RS485 to TCP / IP converter, I use Moxa.
I tried to use your settings, but didn’t get anything. I used to use the MajoDoMo smart home system and it had modbus running on it, nothing happens on the HA even with the parameters you write. If you could take the time to look at where I have an error, or have advice on where to look for an error, I would be very grateful.

MOXA MGate MB3180 web console settings:

Ethernet IP address 192.168.1.190
Mode RTU Slave
Baud rate 9600
Data bit 8
Stop bit 1
Flow control None
FIFO disable
Interface RS-485 2wire
type Modbus serial

configuration.yaml

modbus:
  - name: moxa
    timeout: 5
    type: tcp
    host: 192.168.1.190
    port: 502
    sensors:
      - name: dds238_V
        slave: 1
        address: 12
        precision: 1
        data_type: uint16
        scale: 0.1
        unit_of_measurement: V
        device_class: voltage