How to delay between samping analog inputs with the USB-6212 & DAQ-assistant.

[eziva]

   I am attempting to use analog inputs to create two feedback loops for
two
high voltage controller which are programmed remotely by the analog
outputs.
My problem is that I am getting cross talk between the analog inputs.  It
is my
understanding that the sampling rate is too high and the ADC does not have
time
to settle.  How do I temporally separate the sampling of these analog
inputs to
avoid the problem.  I have added delay but all inputs are sampled at
approximately the same time rather than being spread out throughout the
sampling period.  I can clearly see an effect on the second channel to be
sampled when I change the value on the first channel, however, when I
change
the value on the second channel the first channel remains unchanged.
   I am using labVIEW 2009 and the DAQ-assistant on the USB-6212.
   I have attached the VI but it will not work properly for you because
the
hardware is absent from the feedback loop.  I know the problem is that the
DAQ-assistant is trying to sample all the inputs very quickly.  I just
can't
figure out how to slow the acquisition down.  It is my understanding that
adding delay to the loop simply adds a delay between the end of the
acquisition
of the 5 desired channels and the start of the next acquisition.

Thanks,
Andrew

NI Software :  LabVIEW  version 2009
NI Hardware :  Select one if your issue is related to hardware device
Driver Version :
OS :  Windows XP
Customer Information :

[Steven_K.]

Hi Andrew,

It sounds like you are experiencing ghosting in your application. There are a few ways to improve ghosting in your signal. One way like you said is to lower the sample rate. You can change this by double clicking the DAQ Assistant and change these settings::

Another thing that could help is to see how much source impedance the device you are reading has. If it is high, it could be beneficial to create a voltage follower circuit. Here is a guide: 

KnowledgeBase 208AD10T: Decreasing the Source Impedance of an Analog Input Signal

Lastly there are other suggestions to reduce ghosting in this Knowledgebase:

KnowledgeBase 3L8IETLO: How Do I Eliminate Ghosting From My Measurements?