daq 6211 cross talk issue

[al1999]

hi,

     i am using a 6211 together with softscope from  matlab.

the issue i am seeing is one of signal pickup from channel 14 (or 15) onto channel 13.

signals that i apply to channels 14 or 15, seem to be inpressed onto channel 13 and also inverted.

i have then used a scope (real one) to examine the signal on channel 13 (right at the screw ternimals), but there is no signal there, even though it can still be seen on the softscope trace.

i have put 1k resistors, between the used inputs and ground, in order  to reduce the input impedance of the daq and remove the possiblility of charge injection.

has anyone come across this issue in the past.

thanks in advance

al

[CasiL]

Hi al1999,

This document may help.

http://www.ni.com/white-paper/3344/en/

[al1999]

hi casil, yes ive looked at the document. i have tied most of inputs to gnd via a 1k resistor, and it seems to help, however there still  seem to be  the odd spike showing on the traces. the o/p impedance of most of the devices i have attached are low so i have removed the buffer resistors on these lines.

[CasiL]

What result has removing the buffer resistors to those lines had?