Reading DC signal

[jpsimoes]

Hello,

I am new to Labview, but i am trying for a week know how to read a simple DC signal...

I keep getting zero values on my waveform plot... Is this normal?

Here is my VI, any help would be appreciated, i am using labview 7.1.

[LV_Pro]

The first thing is to confirm that your data acquisition card is working. Using MAX (NI's Measurement & Automation Explorer, should be an icon on your desktop) find the reference to your DAQ card. Opeining that should give you an entry at the top of its screen refering to "test panels". Open one of those. It will give you functional access to all of the various features of the DAQ card. Selecting the channel that you are using should allow you to set up the card to make readings, allowing adjustment of input range, etc. When/if you are getting readings note the various settings you set in MAX and make sure that they are the same in your program. Now run your program. If you are still not getting readings you can either turn on execution highlighing and follow the signals though, putting probes on the signal lines and seeing what the values at each point are. 

P.M.

[jpsimoes]

thank you, i made the test actually i found that it has problems in reading signals form the function generator, with a simple battery the signal read is constant.

I ask now another question, i am trying to use de basic DC measurement block to get the mean value of the signal read...but it keeps asking for mean.vi and i don't know where to reach, i tried some llb from the labview directory but nothing seems to work.

Complimments

thanks in advance

[LV_Pro]

I'm not sure whether it is available in all versions of LabVIEW (i.e. student, base, full, professional) but in mine it is under "Analyze", "Mathematics", "Probability and Statistics". Of course calculating the mean is not difficult, it is   or in less fancy terms, the sum of the values / number of values (the average). If you have an array of numbers it becomes as easy as using the array summation divided by the array size. The array summation (or ADD array elements) function is under "numeric" and the array size is under "array" on the diagram functions.

P.M.