Hi Psmorris,
I'm sorry if I led you down the wrong path.
First when I said you can read different tasks, i meant of different types, I realize that this does not apply to you. I was just trying to explain that DAQmx can do mutliple calls at once, so long as it is NOT to the same task because there is only one timing engine for analog input tasks and such.
Secondly, After further investigation you are correct, DAQmxt does however make it seem like it does delete the data afer it has been read because it throws errors when samples have been "Overwritten", but this is actually only when the write position passes the read position within the circular buffer, and not when the write position replaces a data point within the buffer. This led me to believe that when you read from the buffer, the sample was removed from memory and the write position keeps advancing and filling the buffer.
Anyways I'm glad we have at least clarified that you cannot call the read function at exactly the same time for the same Task without using semaphores.
Good luck with your application!
Charley Dahan
Global Account Manager
