Hallo Everyone,
I am currently stuck at a strange problem: As soon as I start reading my Data from my USB-6210 I get tons of empty Callbacks with 0 Datasets to read. Here is my Code:
_frequenzy = 10000;
_clockTask = new Task();
_clockTask.COChannels.CreatePulseChannelFrequency("Dev2/freqout", "ClockPulses", COPulseFrequencyUnits.Hertz,
COPulseIdleState.Low, 0, _frequenzy, 0.5);
_clockTask.Control(TaskAction.Verify);
_readAiChannelsTask = new Task();
_readAiChannelsTask.AIChannels.CreateVoltageChannel("Dev2/ai0", "Channel 1", AITerminalConfiguration.Differential, 0, 4,
AIVoltageUnits.Volts);
_readAiChannelsTask.AIChannels.CreateVoltageChannel("Dev2/ai1", "Channel 2", AITerminalConfiguration.Differential, 0, 4,
AIVoltageUnits.Volts);
_readAiChannelsTask.Timing.ConfigureSampleClock("/Dev2/PFI6", _frequenzy, SampleClockActiveEdge.Rising, SampleQuantityMode.ContinuousSamples,1000);
_readAiChannelsTask.Triggers.StartTrigger.ConfigureDigitalEdgeTrigger("/Dev2/PFI6", DigitalEdgeStartTriggerEdge.Rising);
_readAiChannelsTask.Control(TaskAction.Verify);
_readAiChannelsTask.Start();
_readAiChannelsTask1Reader = new AnalogMultiChannelReader(_readAiChannelsTask.Stream);
_readAiChannelsTaskCallback = new AsyncCallback(AnalogInCallback);
_readAiChannelsTask1Reader.SynchronizeCallbacks = true;
_readAiChannelsTask1Reader.BeginMemoryOptimizedReadMultiSample(1000, _readAiChannelsTaskCallback, _readAiChannelsTask, _data);
_clockTask.Start();
As you see I read 2 AI Channels with an external Clock. Problem is: I get tons of tons off Callbacks with no Data included. My CallBack looks liek this:
_readAiChannelsTask1Reader.EndMemoryOptimizedReadMultiSample(ar, out _numberOfDataSets);
if (_numberOfDataSets == 0)
{
int x = 0;
}
StreamWriter sw = new StreamWriter(@"C:\AllTheData.txt", true);
for (int i = 0; i < _numberOfDataSets; i++)
{
sw.WriteLine("#" + _totalNumber.ToString(CultureInfo.InvariantCulture) + ": " +
_data[0, i].ToString("0.000", CultureInfo.InvariantCulture) + "," +
_data[1, i].ToString("0.000", CultureInfo.InvariantCulture));
_totalNumber++;
}
sw.Close();
sw.Dispose();
_readAiChannelsTask1Reader.BeginMemoryOptimizedReadMultiSample(-1, _readAiChannelsTaskCallback,_readAiChannelsTask, _data);
As you see I check for empty CallBacks which accure Non-Stop and create massiv amounts of CPU-Load. Non-Empty Callbacks occure with 1k batches of data, as I configured. How do I avoid these?
An additional Question is: the Prescaler for the "external" Clock only reaches to 16. So the lowest available frequenzy I can measure is 6250Hz. I want to go below this (~2kHz). Is there any nice way to achive this? An internal Clock is not an option as I need to synchronize an encoder Read with the AI channels.
Best
Kevin
