Hi Igor,
for using XGB-XBM MODBUS , you have to get inside file program of XG5000, project window, network configuration, standard setting c-net, Operation mode - of the correct serial channel number : instead of using XGT-SERVER, use MODBUS RTU SERVER, Modbus setting - define the adapting following addresses of Modbus addresses(FROM THE FIRST ADRRES -EXMPLE 400001) - adapting to the LS plc ADDRESSES ( D100) . AND THAN WRITE OFFLINE TO PLC