State of the site LVD uint. It is an enumeration type: If the enumeration value is 1, it indicates that the site LVD uint is in the normal state; If the enumeration value is 2, it indicates that the power-off uint disconnect for low voltage; If the enumeration value is 3, it indicates that the power-off uint disconnect bakeground; If the enumeration value is 4, it indicates that the power-off uint local disconnect manually; If the enumeration value is 5, it indicates that the power-off uint disconnect for under temperature; If the enumeration value is 6, it indicates that the power-off uint disconnect for over temperature; If the enumeration value is 254, it indicates that the power-off uint alarm resume; If the enumeration value is 255, it indicates LVD uint operation status unknown.