How Display and Output Acq'd File.VI works?

[SteveChen]

My present project is somewhat similar to Display and Output Acq'd File.vi. But I don't clearly know how it works. My questions are:
1. What will happen if the data-reading from file is faster than output-generation from buffered data?
2. How do they match their paces and in which vi does the matching achieve?
3. Is it possible to get these control information, like interrupt or DMA status in labview application?

Thank you for your help

Steven

[Spencer S.]

Steven,

1. If you attempt to write data to the analog output buffer before there is sufficient space available in the buffer, AO Write.vi will wait until space is available. At that time, it will write the data to the buffer.

2. Synchronizing the file reading and the analog output does not occur in a strict sense. New data is read from file and written to the analog output buffer as the previous data is output.

3. To obtain information concerning a DAQ device, you should use Get DAQ Device Information.vi. It is available in the following location:

Functions >> NI Measurements >> Data Acquisition >> Calibration and Configuration

Good luck with your application.

Spencer S.

[SteveChen]

Thank you for your reply.

As you mentioned in 1., will the device just wait there doing nothing else before the space is available, even though there are other operations to be executed?

Steven

[Spencer S.]

Steven,

No, the device will continue to output the signal. Was this what you were asking? One thing to keep in mind is the fact that AO Write.vi, because Traditional NI-DAQ is not multithreaded like NI-DAQmx, will block access to the driver when it is waiting for buffer space to become available.

Spencer S.