floating voltage DAQPad 6015

[remotecntrl]

Hey.

I have done some basic testing on my DAQPad 6015 and regardless of the pins I have it connected to, it always floats up to its max voltage, 10V.  I am testing it in Measurement and Automation, differential, on demand.  ANy suggestions as to what is going on?

Katie

[johnsold]

Katie,

 I have not used the DAQPad 6015, but on many devices differential inputs must have a path to ground for the bias currents to flow.  Check the users manual for your device to see if some resistors are required.

The cause is input capacitances charging.  The path to ground allows them to discharge.

Lynn 

[Chris_W.]

Hi Katie,

I'm curious what your signal source is. Is it supposed to be connected in a differential configuration or should it be ground referenced? It does however sound like a grounding issue as mentioned in the previous post. Take a look at page 53/264 of the user manual. There is a good explanation of field wiring for different types of signal sources.

http://digital.ni.com/manuals.nsf/websearch/06115536722DAA558625728E007E6BA4

Chris W

[remotecntrl · Accepted solution]

Hey,

I figured it out.  The problem was the grounding.  I had put labview aside for a couple of weeks and then completely forgot that the differential works between two adjacent pins.  Once i changed that out it was working perfectly.  Thanks for your help.  

Katie