public ScadaPointResult FetchCurrentPointData(ScadaDataPoint point)
{
// Fetch a realtime value of the point
DateTime timestamp = DateTime.Now;
//get Realtime value
int nret = RealTime.DNAGetRTAll(point.Id_, out double dval, out timestamp, out string status, out string desc, out string units);
ScadaPointResult scadaPointResult;
if (nret == 0)
{
scadaPointResult = new ScadaPointResult(dval, status, timestamp, units);
return(scadaPointResult);
}
return(null);
}
public async Task FetchAndPlotData()
{
// stop running fetch tasks
if (cts != null)
{
//cts.Cancel();
return;
}
// ***Instantiate the CancellationTokenSource.
cts = new CancellationTokenSource();
// clear the current series of the plot
SeriesCollection.Clear();
// get each point data and bind it to the Series Collection
// iterate through each timeseries point in the config
for (int i = 0; i < LinePlotCellConfig_.TimeSeriesPoints_.Count; i++)
{
IDashboardTimeSeriesPoint pnt = LinePlotCellConfig_.TimeSeriesPoints_.ElementAt(i);
if (pnt.GetType().FullName == typeof(DashboardScadaTimeSeriesPoint).FullName)
{
// handle if the point is a scada point
ScadaFetcher scadaFetcher = new ScadaFetcher();
DashboardScadaTimeSeriesPoint scadaTimeseriesPnt = (DashboardScadaTimeSeriesPoint)pnt;
// fetch the results from the data fetcher
List <ScadaPointResult> results = new List <ScadaPointResult>();
try
{
// ***Send a token to carry the message if cancellation is requested.
results = await scadaFetcher.FetchHistoricalPointDataAsync(scadaTimeseriesPnt, cts.Token);
}
// *** If cancellation is requested, an OperationCanceledException results.
catch (OperationCanceledException)
{
AddLinesToConsole("Existing Fetch task cancelled");
}
catch (Exception e)
{
AddLinesToConsole($"Error in running fetch task: {e.Message}");
}
if (results == null)
{
// handle the null results by printing in the console
AddLinesToConsole("No values returned after fetching");
results = new List <ScadaPointResult>();
}
// Get Plot Values from ScadaResults
List <double> plotVals = new List <double>();
for (int resCounter = 0; resCounter < results.Count; resCounter++)
{
ScadaPointResult res = results[resCounter];
plotVals.Add(res.Val_);
}
// change the plot values spacing in secs and the starting dateTime
if (i == 0)
{
MeasPeriodSecs_ = scadaTimeseriesPnt.FetchPeriodSecs_;
if (plotVals.Count > 0)
{
StartDateTime_ = new DateTime(results[0].ResultTime_.Ticks);
}
}
// getting the required color
string colorString = scadaTimeseriesPnt.ColorString_;
if (colorString == null)
{
colorString = "NULL";
}
SolidColorBrush requiredColorBrush;
try
{
requiredColorBrush = new SolidColorBrush((Color)ColorConverter.ConvertFromString(colorString));
}
catch (Exception ex)
{
requiredColorBrush = null;
//AddLinesToConsole($"Unable to parse the color string \"{colorString}\"");
}
// Add the Data Point fetch results to the Plot lines Collection
SeriesCollection.Add(new GLineSeries()
{
Title = scadaTimeseriesPnt.ScadaPoint_.Name_, Values = new GearedValues <double>(plotVals), PointGeometry = null, Fill = Brushes.Transparent, StrokeThickness = scadaTimeseriesPnt.StrokeThickness_, LineSmoothness = 0, Stroke = requiredColorBrush
});
// https://stackoverflow.com/questions/2109756/how-do-i-get-the-color-from-a-hexadecimal-color-code-using-net
}
}
// ***Set the CancellationTokenSource to null when the download is complete.
cts = null;
}
