Pull-downs for PXI-6509 DIO instrument?

[Barry_Wealand]

We're using a PXI-6509 DIO instrument in an application where a number of configured input channels are connected to hardware-under-test that keeps these signals tri-stated most of the time. We've observed that these signals are prone to floating up or down somewhat non-deterministically. We are using the change-detection feature of this instrument to monitor for changes on these signals, but this floating behavior is prone to cause "false" changes.

I am wondering if there might be an easy way to add pull-down (or pull-up) resistors to these input signals? I notice that the PCIe-6509 product has this option built-in. Are there any accessories that might help with this?

[santo_13]

These are some articles that may be useful - https://forums.ni.com/t5/Digital-I-O/PCIe-6509-Pull-Up-Pull-Down/td-p/3265231

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9GESA0&l=en-US

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9qRSAS&l=en-US

Ideally, use an external pull down resistor based on your DUT, you can create an interposer board that will connect inline with your 6509 card and the cable with the respective connectors with circuit that adds pull down or pull up resistors as needed.