DAQ Assistent Express: All channels read the same value even if some have no signal source.

[epedersen@casconpump.com]

When I utilize the DAQ assistent express VI to read 8 channels, all 8 indicators will display the same value even if only one channel is physically receiving a signal.  The DAQ device is a USB 6341.  The

DAQ Asst Express is set up for differential.

The shied drains are connected to the ground connections for each signal connection on the 6341. 

in short, if i give ch 0 a 5 VDC signal, why do all channels read 5 vdc as well?  (even though nothing is connected to them)

Thanks in advance for the help.

Erik

[GerdW]

Hi Erik,

it's a MUX-type DAQ card and so you will notice crosstalk between channels!

Put some pull-down resistors on those free floating channels…

[Dennis_Knutson]

It's called ghosting and is expected. Search for options to remove/minimize.