/// <summary>
/// Read historian data from server.
/// </summary>
/// <param name="instanceName">Historian instance name.</param>
/// <param name="startTime">Start time of query.</param>
/// <param name="stopTime">Stop time of query.</param>
/// <param name="measurementIDs">Measurement IDs to query - or <c>null</c> for all available points.</param>
/// <param name="resolution">Resolution for data query.</param>
/// <param name="seriesLimit">Maximum number of points per series.</param>
/// <param name="forceLimit">Flag that determines if series limit should be strictly enforced.</param>
/// <param name="timestampType">Type of timestamps.</param>
/// <returns>Enumeration of <see cref="TrendValue"/> instances read for time range.</returns>
public IEnumerable <TrendValue> GetHistorianData(string instanceName, DateTime startTime, DateTime stopTime, ulong[] measurementIDs, Resolution resolution, int seriesLimit, bool forceLimit, TimestampType timestampType = TimestampType.UnixMilliseconds)
{
// Cancel any running operation
CancellationToken cancellationToken = new CancellationToken();
Interlocked.Exchange(ref m_readCancellationToken, cancellationToken)?.Cancel();
SnapServer server = GetServer(instanceName)?.Host;
IEnumerable <TrendValue> values = TrendValueAPI.GetHistorianData(server, instanceName, startTime, stopTime, measurementIDs, resolution, seriesLimit, forceLimit, cancellationToken);
switch (timestampType)
{
case TimestampType.Ticks:
return(values.Select(value =>
{
value.Timestamp = value.Timestamp * 10000.0D + 621355968000000000.0D;
return value;
}));
case TimestampType.UnixSeconds:
return(values.Select(value =>
{
value.Timestamp = value.Timestamp / 1000.0D;
return value;
}));
default:
return(values);
}
}
/// <summary> /// Gets loaded historian adapter instance names. /// </summary> /// <returns>Historian adapter instance names.</returns> public IEnumerable <string> GetInstanceNames() => TrendValueAPI.GetInstanceNames();
