/// <summary>Selects the data source for OPC reads (from device, from OPC cache, or dynamically determined).</summary>
[v1_enum] typedef enum 
{
	/// <summary>The data source (memory, OPC cache or OPC device) selection will be based on the desired value age and 
	/// current status of data received from the server.</summary>
	ByValueAge = 0,	// OCK_DS_BY_VALUE_AGE
	/// <summary>OPC reads will be fulfilled from the cache in the OPC server. </summary>
    Cache = 1,		// OPC_DS_CACHE
	/// <summary>OPC reads will be fulfilled from the device by the OPC server. </summary>
	Device = 2,		// OPC_DS_DEVICE
} DADataSource;