/// <summary>Holds data value, timestamp and quality, abbreviated sometimes as VTQ. This is a common combination in OPC,
/// e.g. returned when an OPC item is read.</summary>
/// \incpart{Example (JScript),IEasyDAClient.ReadItem.Main.js,//+++,//---}
/// \incpart{Example (VBScript),IEasyDAClient.ReadItem.Main.vbs,Rem+++,Rem---}
[
	object,
	uuid(7C486189-8B81-4902-83E0-8F695F6786FB),	// IID changed for V5.0
	dual,
	oleautomation,
	nonextensible,
	helpstring("Holds data value, timestamp and quality, abbreviated sometimes as VTQ"),
	pointer_default(unique)
]
interface IDAVtq : IDispatch
{
	/// <summary>Gets or sets the data value.</summary>
	[propget, id(1), helpstring("Gets or sets the data value")] 
	HRESULT Value([out, retval] VARIANT *pVal);
	//[propput, id(1), helpstring("property Value")] HRESULT Value([in] VARIANT newVal);
 
	/// <summary>Gets or sets the timestamp.</summary>
	[propget, id(2), helpstring("Gets or sets the timestamp")] 
	HRESULT Timestamp([out, retval] DATE *pVal);
	//[propput, id(2), helpstring("property Timestamp")] HRESULT Timestamp([in] DATE newVal);
 
	/// <summary>Gets or sets the quality.</summary>
	[propget, id(3), helpstring("Gets or sets the quality")] 
	HRESULT Quality([out, retval] LONG *pVal);
	//[propput, id(3), helpstring("property Quality")] HRESULT Quality([in] LONG newVal);
 
	/// <summary>Formats the data value for display.</summary>
	/// <param name="pvarResult">Receives the return value.</param>
	/// <returns>Returns the formatted data value.</returns>
	/// <remarks>Returns empty string when the quality is bad. The current data value can be a null reference.</remarks>
	[id(101), helpstring("Formats the data value for display")] 
	HRESULT DisplayValue([out, retval] VARIANT* pvarResult);
 
	/// <summary>Returns whether the <see cref="Value"/> contains valid data.</summary>
	/// <param name="pvarResult">Receives the return value.</param>
	/// <returns>Returns True when the <see cref="Quality"/> is not Bad.</returns>
	[id(102), helpstring("Returns whether the Value contains valid data")] 
	HRESULT HasValue([out, retval] VARIANT* pvarResult);
 
	/// <summary>Returns a string that represents the current <see cref="DAVtq"/>.</summary>
	/// <param name="pvarResult">Receives the return value.</param>
	/// <returns>A string representation of the current value, timestamp and quality.</returns>
	/// <remarks>
	/// <para>When the quality is bad, the returned string contains just the timestamp and quality. Otherwise, the
	/// returned string contains also the data value, and its type.</para>
	/// </remarks>
	/// \incpart{Example (JScript),IEasyDAClient.ReadItem.Main.js,//+++,//---}
	/// \incpart{Example (VBScript),IEasyDAClient.ReadItem.Main.vbs,Rem+++,Rem---}
	[id(103), helpstring("Returns a string that represents the current DAVtq")] 
	HRESULT ToString([out, retval] VARIANT* pvarResult);
};