ADAM4150 的WPF中串口无法打开

public class Global
{
public static ICS.Models.Com.ComSettingModel _ComSetting = null;
///
/// 获得Com口以及通道配置
///
public static ICS.Models.Com.ComSettingModel ComSetting
{
get
{
if (_ComSetting == null)
{
_ComSetting = new ICS.Models.Com.ComSettingModel();
//代码直接设置数字量串口
_ComSetting.DigitalQuantityCom = "Com2";
}

            return _ComSetting;
        }
    }

    /// <summary>
    /// ADAM4150
    /// </summary>
    public static ADAM4150 ADAM4150Provider
    {
        get
        {
            return (ADAM4150)ClassFactory.GetProvider(equipmentCategory.ADAM4150, ComSetting);
        }
    }
}
    为什么ADAM4150Provider会得到不同的结果？