/// <summary>
/// Reads the specified group items.
/// </summary>
/// <param name="items">The group items.</param>
/// <param name="dataSource">The data source.</param>
/// <returns>
/// The values of the group items.
/// </returns>
public OpcDaItemValue[] Read(IList <OpcDaItem> items, OpcDaDataSource dataSource = OpcDaDataSource.Cache)
{
CheckItems(items);
CheckSupported(OpcDaGroupFeatures.Read);
int[] serverHandles = ArrayHelpers.GetServerHandles(items);
HRESULT[] ppErrors;
OPCITEMSTATE[] ppItemValues = As <OpcSyncIO>().Read((OPCDATASOURCE)dataSource, serverHandles, out ppErrors);
OpcDaItemValue[] result = OpcDaItemValue.Create(this, ppItemValues, ppErrors);
OnValuesChanged(new OpcDaItemValuesChangedEventArgs(result));
return(result);
}
/// <summary>
/// Reads the specified group items using MaxAge. If the information in the cache is within the MaxAge, then the data
/// will be obtained from the cache, otherwise the server must access the device for the requested information.
/// </summary>
/// <param name="items">The group items.</param>
/// <param name="maxAge">The list of MaxAges for the group items.</param>
/// <returns>
/// The values of the group items.
/// </returns>
/// <exception cref="System.ArgumentException">Invalid size of maxAge;maxAge</exception>
public OpcDaItemValue[] ReadMaxAge(IList <OpcDaItem> items, IList <TimeSpan> maxAge)
{
CheckSupported(OpcDaGroupFeatures.ReadMaxAge);
CheckItems(items);
int[] serverHandles = ArrayHelpers.GetServerHandles(items);
if (serverHandles.Length != maxAge.Count)
{
throw new ArgumentException("Invalid size of maxAge", "maxAge");
}
// int[] intMaxAge = ArrayHelpers.CreateMaxAgeArray(maxAge, items.Count);
DateTimeOffset[] timestamps;
HRESULT[] errors;
OpcDaQuality[] qualities;
object[] ppvValues = As <OpcSyncIO2>()
.ReadMaxAge(serverHandles, maxAge, out qualities, out timestamps, out errors);
OpcDaItemValue[] result = OpcDaItemValue.Create(items, ppvValues, qualities, timestamps, errors);
OnValuesChanged(new OpcDaItemValuesChangedEventArgs(result));
return(result);
}