Error -200474 (I'm using Hardware Timed Single Point mode)

[Milosh]

Why I'm getting (random time after measure start) error -200474 (Specified operation did not complete, because the specified timeout expired. Device: Dev1 Task Name: aiTask)?
This is configuration of Task:
myTask.AIChannels.CreateVoltageChannel("Dev1/ai1,Dev1/ai2","aiChannel1,aiChannel2",AITerminalConfiguration.Rse,-2,2,AIVoltageUnits.Volts);
myTask.Timing.ConfigureSampleClock("",40,SampleClockActiveEdge.Rising,SampleQuantityMode.HardwareTimedSinglePoint);
analogInReader.BeginReadSingleSample(analogCallback,null);

This is analogCallback function:
data = analogInReader.EndReadSingleSample(ar);
//plot my data[0] and data[1]
analogInReader.BeginReadSingleSample(analogCallback,null);

It work, but sometimes I get error message -200474. Why?

[AlanArmstead]

Milosh,
I'd like to help you out. Could you please post some more information about your system.
What is your OS?
What hardware are you using?
What version of NI-DAQ do you have?
Is that a C#.net program?
Are you running this program continuously?
If so, is there a reason you are using single point acquisition as opposed to continuous?
Any other pertinent information would be helpful also.
-Alan A.

[Milosh]

Thank you for your interest,
OS: Win 2000 sp4
HW: PCMCIA DAQ card 6024E, PC notebook Celeron 2.4 Ghz, 256 RAM, SiS chipset...
NI-DAQmx 7.2
Yes it is C#.net program
I am running this program continuously, rate is 40Hz
I am using single point acquisition because I want to measure voltage in real time.
I have to plot value immediately for visual feedback.
Thank you for answer & sorry for my english 🙂
Milosh

[WM_John_Weeks]

---

@Milosh wrote:
I have to plot value immediately for visual feedback.
Thank you for answer & sorry for my english 🙂
Milosh

---

I'm doing the same thing. I use regular scanning, and DAQmxReadAnalogF64() with a timeout of 0.0. Then check sampsPerChanRead to see if any samples were actually read. I also check the error return for errors DAQmxErrorTimeoutExceeded and DAQmxErrorSamplesNotYetAvailable so that I can check for errors but ignore these.

Be aware that if you specify DAQmx_Val_GroupByChannel, the data will be arranged like this:

c1_1, c1_2, 0, 0, ..., c2_1, c2_2,...

where I have used c1_2 to indicate channel 1, second sample. That is, if you specify N samples per channel, the first sample for the second channel is at point N in your array.