DAQmx concurrent tdms read

[katratzi]

Hi,

i am measuring a voltage using the NI9223 and log the data to a tdms file. Since my signal processing takes a lot of time, i try to read the tdms file while the measurement is still active.To do this, I modified the "Concurrent Access to TDMS file" example. 

Unfortunately the TDMS Read VI always responds wit a error:

LabVIEW: End of file encountered.

=========================
NI-488: Invalid argument or arguments to function call.

I already tried different offsets and data lengths (-1) but nothing seems to work. 

Thanks a lot for your help

[crossrulz · Accepted solution]

DAQmx has exclusive access to the TDMS file during the logging process.  That is one of the reasons it can log data faster than a Producer/Consumer.

For your exact example, you should be using the Log And Read mode and use the DAQmx Read inside of the loop to then write to your chart.