AI/AO synchronization for Active Noise Control

[RVR224]

I have PCI-4722 and PCI-6733 cards. I would like to implement an active noise contol system where I can record the signal using 4722, filter it and generate an anti-noise thro' 6733. Is there any example for simultaneous  analog data acquisition and generation that could be used for my case?

[Travis G.]

Hello RVR224,

There are some good multi-device synchronization examples installed with the NI-DAQmx driver in the LabVIEW Example Finder (Help > Find Examples).  You can browse for these examples in the Example Finder under Hardware Input and Output > DAQmx > Synchronization > Multi-Device.  Specifically, take a look at the example titled Multi-Device Sync - AI and AO - Shared Timebase & Trig - DSA.vi.  Your devices must reside in a PXI chassis or you must connect them together via a RTSI cable in order to share timing and triggering signals between multiple devices.  Take a look at the following tutorial for more information:

Timing and Synchronization Features of NI-DAQmx

What your really talking about here is a control application, where you acquire some data, perform some processing on it, and output some new data based upon the results.  Most control applications are based around a hardware timed single point acquisition, which means you acquire, process, and output a single sample at a time.  This type of acquisition is very processor intensive, and you will run into some limitations of the rate your system and your DAQ devices can perform this operation.

I hope this helps,
Travis G.
Applications Engineering
National Instruments
www.ni.com/support