DWDT Boolean Array to Digital.vi is killing me!

[Ricotta]

Hey guys,

I've run into a bit of an issue using my PIXe-6556. The acquisitions are lightning quick, I am able to get almost 8 million bits from the card in sub-500ms. What is killing me is all the post-processing taking on the order of 8-10 seconds. Right now I am using "DWDT Boolean Array to Digital.vi" and "DWDT Digital to Boolean Array.vi" to create and retrieve my digital waveforms. I realize this isn't the most efficient format, probably, for storing the data, but it was easily compatible with generating waveforms on my PXIe-6556 with the "Write Named Waveform.vi". Can someone give me some alternatives to what I could do to speed this up? I've looked into converting the numbers myself, but the data format for the Digital Data waveform is an array of U8 1-bit values...

Some more information. I use this method for 2 main purposes:

1) 1 line @ 20Mhz for a Delta-Sigma modulator (~8 million samples at a time). I run this through a software sinc filter once I retrieve the data. I only generate a clock waveform.

2) A 10MSPS ADC. This puppy runs at the absolute max of the 6556 @ 200Mhz. There are 4 digital lines to generate, and 4 digital lines to receive. I try to acquire on the order of 10000 samples @ 16-bits... So well over a million samples on 8 channels.

Thanks for the help,

-Mitch

[Libbin_la_vida_loca]

Hey Mitch,

The NI-HSDIO VIs are polymorphic and can accept multiple data types from waveform to U32 to U8. There is no need to post-process your data, just have it output in the format that you want.

http://zone.ni.com/reference/en-XX/help/370520K-01/hsdioviref/hsdio_write_nm/

http://zone.ni.com/reference/en-XX/help/370520K-01/hsdioviref/hsdio_read_wvfm/