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usb-6255 as spi master (For DDS control)

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  Hello,

I am using USB-6255 data acquisition device.
 I would like to control a DDS using the Digital I/O,
connecting it to the DDS using SPI connection (from the digital I/O to the DDS).
has anyone know about a way / done anyting like that?

Thanks,
Lior.
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Hi,
a few more additions:
I'm using Windows XP, the programming is done using C# (.Net Framework 3.5).
by the way, I'm reffering to Direct Digital Synthesizer (not synthesis).
Thanks.
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Hi Lior,

The most straight-forward way to do SPI communication with an M Series board is to generate the entire command sequence on the digital lines. You can clock your communication with either software or hardware. Software would be a bit simpler to implement, but hardware is uniform in time.

In either case, you would create an output waveform that contained your clock, select, and MOSI lines and write it to the digital output lines. For MISO, you would need an output waveform that generated the clock and select lines and read the digital input line at the same time.

If you want to use hardware to time the operation, you'll need to use a counter to generate the sample clock.
Joe Friedchicken
NI Modular Instruments Application Software
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