Glitches on digital signal from 5751

[Rabbi5751]

I am driving four LMH6574MA multiplexers with digital signals from NI-5751 digitizer (running on NI PXI 7953R FlexRIO). There are glithches on all the digital signals (signal frequency is 40 MHz). Is there a way to clean these signals up in software?

[Bob_Schor]

It's either Hardware, Software, or Cabling (and you haven't told us much about any of these, especially software -- no code).  Plus I'm confused -- isn't the 5751 an A/D converter?  What are the nature of the signals you are digitizing?  By "digital signals", do you mean the digitized version of the analog signals?  Are the "glitches" present on the input (i.e. if you look with a scope, do you see "noise")?  Are you looking to filter your digitized signal?  Can you show us a "clean signal" and one with glitches?

BS

[crossrulz]

The 5751 does also have 8 digital input lines and 8 digital output lines.  According to the spec, the maximum toggle frequency is 1MHz (that is with all of the Digital Outputs toggling).  So you might just be going too fast for the board.  Of course, there are many possible noise issues here: lack of grounding, ground loop, lack of sheilding, bad connection to test board, etc.

[mikeporter]

Can you show a bit more of the circuitry involved? I'm not clear where the glitches are from your description. Maybe a bypass cap or two are in order?

Mike...

[David-A]

Did you place the AI node in the IO Mod Clock 0 clock domain?

If you don't have those analog input nodes inside of the correct clock domain you'll be performing an unsafe clock crossing that will result in glitching.

The user manual walks you through how to add the IO Module Clock 0 to a project. Or you could start from the getting started example.