NI 9205 Cross Talking, Ghosting, or not registering known signals.

[Kdscott5310]

The Cross talk on this card is horrendous. Is there any way to fix this. At are ends with this card. Trying to read 5 differential signals 0-10 volts. 1 shunt differential 0-50mV. 3 Single Ended 0-5 volts Omega PX419. And 2 single ended 0-10 volt signals. I can get one of the channels to read the correct voltage using calibrated pressure supply, and can see one other linear actuator voltage responding. All of the other channels are either not responding noise or ghosting between channels, or cross talking.  We plug in to a 9201 and all the cross talking and ghosting goes away. We tested the cables plugged in ground cables. Tried different transducers. Rewired cabling to the breakouts. We can see the correct voltages at the terminals of our breakouts for each device but the card is representing them at a different voltage or not at all just some copied over noise. Kind of crazy that this $1200 dollar card doesn’t hold its weight considering throwing all 4 we bought into the river. As right now they are useless unless someone has any remedy. Don’t get me started on the NI tech support. Seen better support from Walmart. 

[Ahmed99]

Can you know the output impedence of your transducer ? is it above 1 kohm ?

[Kdscott5310]

Yes it is around 5k ohms. On all three transducers. Still not getting readings on my differential channels nor my other single ended. The 9201 reads them fine but i will have to use two chassis spots to achieve the goal as well as now wasted 4k in cards

[santo_13]

Of course, both have different specifications and hardware architecture. Please review all the solutions described in https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P84RSAS&l=en-US

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YHy6CAG&l=en-US

A few important details I notice are,

• 9205
  
  • 16-bit ADC
  • Input impedance >10G || 100pF
  • 100kHz crosstalk -65dB adjacent channels
  • Settling time +/-120ppm full-scale step to +/-8 LSB (4us convert time)
  • 
• 9201
  • 12-bit ADC
  • Input impedance 1M || 5pF
  • 10kHz crosstalk -75dB
  • Settling time full-scale step to 1 LSB in 2us
  • 

[Ahmed99]

output impedance should not exceed 1 k ohm , check this

https://www.ni.com/en-lb/support/documentation/supplemental/12/using-a-unity-gain-buffer--voltage-fo...