Adapter board for protocol translation of energy meters

We need to design an adapter board for protocol translation (MODBUS, DLMS/COSEM) to encrypted serial data for the following energy meters : Wilis : E3201 & E30605 EDMI : Mk6, Mk 3, Mk10 Actaris : SL7000, ACE6000 Landis+Gyr : ZMD, ZMG, ZMQ Iskra : MT860, MT830, MT372 Elster : A1700 Wasion : DTSD341 EMH : LZQJ You can use any MCU or arduino board. ENERGY METERS adapter board RS485 serial encrypted data The pcb of the adapter board should be low power and small size.