Hallo all,
I have posted my problem in the forum LabVIEW
http://forums.ni.com/ni/board/message?board.id=170&message.id=250454
unfortunately so far I have not received any good solution, so I contribute my problem in this group for it concerns about DAQmx.
I write a LV code which reads data from USB 6211
and saves them with time instants in a text file, but the time instants
don't correspond the sampled data. The time values are generated by
elapsed time, after build array with the data read from DAQ, they are
fed to the write to a text file. The test signal is 10 Hz, but the text
file yields 0.2 Hz signal. How could I synchronize them?
I play further with this vi code, and found:
The sampled data largely depend on the sample rate which is set at
DAQmx Timing. In case the rate is set larger than 63kS/s, there will
be no data in the text file. Smaller the rate is, the better results
man could get, i.e. when I set the sample rate at 1kS/s, mostly the
result seems loyal to the voltage curve generated from a function
generator. Another weird thing which comes to pass is that sometimes
the beginning data are compressed no matter whether rate is set small
or large, but some times it dosn't happen.
My computer is quipped with usb2.0 and usb1.0/1.1, when I plug the
usb6211 into the 1.0/1.1 socket, the computer can identify it, but the
computer fails to identify if it is connected to 2.0 socket. In the
control panel, the driver to the usb advanced hostcontroller is there.
The driver for usb6211 has been surely installed for it seems to work
properly with usb1.0/1.1 interface. How could I put it straight?
Any advice is greatly appreciated,
win2
