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a question on precision

Hai,
I am using a NI 6110E daq board for my data acqusition. I used this board to acquire data on three channels, two of which are voltages and one being current. I use the program continious acqusition to spreadsheet file.vi to record the data. I have made small changes to fit my needs. First it was showing only 3 decimal places precision, so i changed the %.3f to %.6f for better precision.
 
Now coming to the problem. The voltage i measure is scaled to a value between +10v and -10v. And the current I measure is between +1v and -1v. So in the front panel of the vi, i change the channel settings to get better resolution, ie two channels range to +/-10 and one channel range to +/-1. After I acquire the data, i plot it using matlab. I repeated the same experiment using the channel range to +/-1v for all the channels. As expected the voltage reading were cut off at 1. But in this case the current reading was more clear than when two of the channels were kept at +/-10.
 
I do not understand why the above is happening to the channel where I measure current. If anyone can explain it or can help me solve this it will be very helpful.
 
Thank You,
Siva.
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Siva,

Thank you for contacting National Instruments.

I will need some more information from you to answer your question. First, please verify that you are using the PCI-6110, and not a E Series device.  Also, please describe how you are measuring current. Are you using a shunt resistor? If so, what is its value? What is your input configuration (differential, RSE, NRSE)? What current values do you expect to be seeing (in Amperes)? Are you using NI-DAQmx or Traditional NI-DAQ drivers to communicate with your device? What do you mean by "current reading was more clear"?

Thanks

--
Michael P
National Instruments
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