public static SimulateVariableModel Create(IEnumerable <SimulateVariableUnit> svunits)
        {
            SimulateVariableUnit svunitf = svunits.First();

            if (svunitf is SimulateBitUnit)
            {
                return(SimulateBitModel.Create(svunits));
            }
            if (svunitf is SimulateWordUnit)
            {
                return(SimulateWordModel.Create(svunits));
            }
            if (svunitf is SimulateDWordUnit)
            {
                return(SimulateDWordModel.Create(svunits));
            }
            if (svunitf is SimulateFloatUnit)
            {
                return(SimulateFloatModel.Create(svunits));
            }
            return(null);
        }