8Byte Modbus Herholdt Controls ECS

[BidiCH]

Hello everybody

I've been trying to read out an Optec energy meter (Heroldt Controls ECS) using Modbus for a while. 
In principle, this also works without any problems. However, it does not work properly with the 8byte objects. 

In the code excerpt you can see it in the addresses 4322 and 4326. 
In the manual page 6, point 3.4.4. Reading a 8 bytes value listed as it should work. Unfortunately I don't know what to do next.
How do you have to do this conversion in the profile? Can this conversion be calculated directly in a Modbus profile?
Thank you Bidi

  Optec_Built_in_ModbusProtocolM1PROM3PRO-Technicaldescription.pdf (Size: 1.32 MB / Downloads: 6)

Code:

{
    "product_code": "M3PRO",
    "manufacturer": "Optec (Herholdt Controls)",
    "name": "M3PRO reduziert",
      "product_range": "Energiezähler",
      "description": "Energiezähler M3PRO",
      "mapping": [   
        { "bus_datatype": 14, "datatype": "float32", "read_swap": "bw","address": 4152, "type": "register", "units": "kW","name": "Wirkleistung L1"},
        { "bus_datatype": 14, "datatype": "float64", "read_swap": "bw","address": 4322, "type": "register", "units": "kWh","name": "Wirkenergie Bezug T1+T2 total"},
        { "bus_datatype": 14, "datatype": "float64", "read_swap": "bw","address": 4326, "type": "register", "units": "kWh","name": "Wirkenergie Lieferung T1+T2 total"}
        ]
}