How to reduce PXI-6509 crosstalk?

[BuffaloGuy]

I have a PXI-6509 board in a PXIe-1073 chassis, with an RG1005050 cable.  I'm using the DIO pins exclusively for digital output.  I'm controlling the 6509 using DAQmx and MS Visual C++.

When I set certain bits high, I'm getting "glitches" or crosstalk with amplitude of 3-4 Volts and duration of 20-50 nanoseconds.  The crosstalk is triggering my Device Under Test (DUT) and my measurement (oscilloscope) at undesired times.  I'm wondering if there's a DAQmx setting to slow down the rise and fall times on digital outputs, and thus reduce the crosstalk.

Thanks for any help or suggestions!

[crossrulz]

Ribbon cable is horrible for noisy situations.  But here are a couple of ideas to help:

1.  Make sure all of the DIO are either set to be output and unused are set to 0 or make sure the unused DIO are inputs with the signal grounded on your test board.

2.  Get a ferrite that is made to clamp onto a 50-pin ribbon cable.  They are just iron cores that go around the cable, but they act as a kind of filter.

[Dennis_Knutson]

NI does sell a shielded cable for your device - http://sine.ni.com/nips/cds/view/modelpopup/p/pcat/918/lang/en

[BuffaloGuy]

Thank you both for your suggestions.  The ferrites didn't work, and a shielded cable wouldn't have been convenient, but you both got me thinking about the problem the right way.  I ended up debouncing the signal in downstream firmware.  I should have mentioned in my original post that firmware was available.

Kudos sent to both of you, and thanks again!