Not sure if this was the right board - my errors have occurred a few ways.
I have 17 channels in a task, measuring analog voltages and thermocouples. The task was designed in MAX. Continuous sampling, 10 samples, 100Hz sample rate, 10 second timeout, no trigger, internal clock. By all accounts on http://digital.ni.com/public.nsf/allkb/FEF778AD990D5BD886256DD700770103 I am well within the tolerances of timeout. The DAQ is connected to the PC via ethernet cable. It is not on a network per se - the network cable is direct between PC and DAQ, and the IP address is static.
I wrote a program in Measurement Studio 2010 (using Visual C# 2008 Professional). I used the sample code from NI to set up the asynchronous reads (copy and paste). I'm using BeginMemoryOptimizedReadWaveform as per the example.
My test has to run for 5 hours continuously to monitor a unit in operation. Too often, I get this -200284 error. Unfortunately, this causes me to have to exit the program because I haven't figured out how to gracefully handle it and restart the task (even through exception handling). That means I have to start my 5 hour test over again - not a good thing, especially when it happens sporadically, and often within 5 hours. Sometimes, it doesn't happen for two days.
I thought something in my code was causing it, but when troubleshooting in MAX, it also threw that error - ONCE, but it did.
There is no reason it should be timing out or not having enough samples in a task with a 10s timeout, when it should collect the required number of samples in 0.1s.
Unfortunately, there is nothing I can do to duplicate the error.
A few moments ago, I used MAX to try to duplicate this error with a virtual DAQ. I could easily trigger it at 101 samples, 100Hz sample rate, and a timeout of 1s - it triggered every time I ran the task. However, at 99 samples, 100Hz sample rate, and a timeout of 1s (very close to the timeout threshold) it ran for 15 minutes before stopping due to a -200284 error.
What can I do to avoid this fault from occurring? If there's nothing that can be done, how I can I code my program in Measurement Studio to gracefully restart the task with no user input? (Nobody sits and watches this thing for 5 hours straight; it would be worse than watching grass grow.)
Actual DAQ setup and read code:
Setup Code:
public bool connectDevice()
{
try
{
this._continuousTask = DaqSystem.Local.LoadTask(_taskName);
this._continuousTask.Control(TaskAction.Verify);
this._runningTask = this._continuousTask;
this._daqChannelReader = new AnalogMultiChannelReader(this._continuousTask.Stream);
this._callback = new AsyncCallback(ReadCallBack);
this._daqChannelReader.SynchronizeCallbacks = true;
this._daqChannelReader.BeginReadWaveform(Convert.ToInt32(_continuousTask.Timing.SamplesPerChannel), _callback, _continuousTask);
OnConnectionChanged(new ConnectionEventArgs(true, ""));
return true;
}
Read code:
private void ReadCallBack(IAsyncResult ar)
{
try
{
try
{
_data = _daqChannelReader.EndReadWaveform(ar);
OnDataRead(DeviceDataEventArgs.DataFromDevice(this));
if (_runningTask == ar.AsyncState)
{
{
_daqChannelReader.BeginMemoryOptimizedReadWaveform(Convert.ToInt32(_continuousTask.Timing.SamplesPerChannel), _callback, _continuousTask, _data);
}
}
}
catch (DaqException ex)
{
#if(DEBUG)
Console.WriteLine("E: " + System.DateTime.Now.ToString() + " - DAQ Read Error - " + ex.Message);
Console.WriteLine(" - attempting to hold connection open during read failure");
#endif
// _continuousTask.Dispose();
// OnConnectionChanged(new ConnectionEventArgs(false, ""));
// _runningTask = null;
}
}
catch
{
// Catches object disposal exceptions
}
}
The task disposal was in the sample code; it's commented out to try to keep it open since disposing it still didn't allow me to restart the task in code. The outer try-catch is to keep from throwing an error when the program is closing and the task is still running; it doesn't prevent -200284 from occurring.
I'll try any suggestions... thanks in advance!
