Analog Input varying erratically- I have checked all recomendation made by others in discussion fourm

[balajikasthuri]

I have connected a floating 5V DC to Anolog input ch0. I observe very eratic values when I view it using MAX.

I connected it in both differential and NRSE mode. While in NRSE mode, I connected signal positive to ACH0, negetive to AISENSE and AISENSE to AGND through a 10k resistor. I constantly read -10V in MAX.

As required for DIFF mode, I connected signal to ACH0, negetive to ACH8 and AGND to ACH8 through 10K resistor.
I read railing voltage from -10 to 10V.

I dont understand the reason for this. I think I have done everything as mentioned in the mannual.

Can any one help ?

[David Mc]

When hooking up your DIFF or NRSE floating signal, be sure that you do use TWO resistors:

DIFF:
-----
signal+ to ACH0 and through resistor to AIGND
signal- to ACH8 and through resistor to AIGND

NRSE:
-----
signal+ to ACH0 and through resistor to AIGND
signal- to AISENSE and through resistor to AIGND


Also, everytime you change your connection types, please remember to check that you have selected the appropriate connection type in the device's properties in Measurement and Automation Explorer.

David McClelland
National Instruments