Discussion:
DAQmx_Val_OnDemand
(too old to reply)
vr46
2008-08-02 21:10:06 UTC
Permalink
I'm trying to read AI channels from a 6033E card with DAQmx and I invariably get error no matter what I do. Here is one of them DAQmxStartTask error:An error has occurred while attempting to configure the device for an analog input acquisition.If an external master timebase is being used, make sure the source is connected and generating an appropriate clock. Otherwise, contact National Instruments Technical Support.Task Name: ai64Status Code: -200329I can run the same program on a 6052E and it worksI tried to set clock w/ for instance or not calling it at all and it won't make a differenceerror=DAQmxCfgSampClkTiming(taskHandle,NULL,10000.0,DAQmx_Val_Rising,DAQmx_Val_FiniteSamps,nSamples);Nevertheless, I can run the DAQmxTestPanels and I can read at least 1 channel in OnDemand mode.So what is it that the test panel does to specify the OnDemand mode and what is the proper sequence of DAQmx calls to get it to work.Calling DAQmxSetSampTimingType(taskHandle, DAQmx_Val_OnDemand);does not make a difference to me.Regards
samantham
2008-08-05 23:40:07 UTC
Permalink
Hello,
Please confirm that the 6033E does in fact work with the Test Panel in Measurement and Automation Explorer (MAX) with On Demand Acquisition Mode.  I was unsure if you were referring to the 6052E or 6033E here.
I am also curious to know if you have tested the 6033E in Finite or Continuous Mode inside the Test Panel.  Please let me know if the results is the same error number.  Please just try testing one AI channel from the Test Panel to limit troubleshooting. 
How many channels are in getting setup at 10 kS/s when running the application in text based code.  What version of the DAQmx is installed? 
vr46
2008-08-06 13:40:11 UTC
Permalink
This is under Linux by the way. Yes, both 6033 and 6052 work under DAQmxTestPanels. But they both only work with OnDemand mode which is really what I want to use.Neither work in continuous data acquisition mode. But I think this is general problem w/ DAQmx for linux.So what is it that the DAQmxTestPanels does to get it to work under onDemand mode as I can't find any documentation/example specific to that.Thank you
samantham
2008-08-13 04:10:07 UTC
Permalink
Hello,
 
I reviewed the Readme for the Linux versions of the DAQmx driver and just wanted to make sure that we are in fact dealing with PCI devices and not PXI.  The 6033E is not supported in Linux with a PXI form factor.
 
I also to mention the most issue that I have searched through related to this error have been resolved with an repair by National Instruments.  I realize that the 6033E is operating in the Test Panels so this might be a stretch.  Please give me some feedback if this card has been tested on another computer?
 
The sequence of code that is need for an On Demand Mode of AI acquisition is simply a DAQmx Create AI Voltage Chan, DAQmx Start Task, DAQmx Read (loop read of multiple data points over time), and last a DAQmx Clear Task.  No where is a DAQmx Timing call needed.  Please try this simple sequence and provide some feedback. 
Loading...