Data Acquisition using NI-MAX 15.0

[tomp93]

I was trying to acquire data from SCXI- 1100 using NI-MAX15.0 . I have added Devices and interfaces and created virtual channels with map ranges as scale. But when i am feeding signal to the card, the output showing in the driver is same as what i am providing as input to card. It is not converting signal to the scale i specified.

Could you please help me to solve this problem.

[Bob_Schor]

You wired the third function in your Block Diagram wrong.  Oops, maybe it's the fourth function -- my powers of telepathy are not working as well today (need more coffee).  Why don't you help by posting your VI (not a picture, but the actual VI) so we can see what you've tried and can suggest what might be wrong.

Bob Schor

[tomp93]

Actually it's not in VI.. I was testing with NI MAX Driver software.. There itself it's not converting the acquired values to physical quantity even though I specified scale..

[crossrulz]

Still, screen shots will help a lot here in diagnosing the issue.

[Bob_Schor]

Interesting.  I recently programmed a triaxial accelerometer that had a nominal offset of 1.5v and a nominal gain of 0.5v/g.  I made scales in MAX and viewed the results by hand, only to find that the given offset and gain were "within 10%".  I subsequently wrote a very quick calibration routine that involve taking 6 10msec measurements from the accelerometer held stationary in six (approximate) orientation and solving for the three offsets and gains.  When these are used to build (in DAQmx) the scales, each axis goes between +1g and -1g (when not being moved).

Since we still don't know what you are doing, either your version of MAX is completely misbehaving or (dare I say it?) you are doing something (unknown) wrong.

Bob Schor

[tomp93]

Ohh.. May be i am wrong.. i am new to labview... not sure whether i have done correctly or not..  could you please check the screenshots...

[crossrulz]

The only issue I am seeing is that the Signal Input Range should be after scaling values.

[tomp93]

I didnt get you. Could you please tell me the complete procedure when you want to acquire signals from a sensor using NI-MAX software. Then i will be able to find out my mistake. Use Scale as Map Ranges

[RavensFan · Accepted solution]

Look at the input setup you have in the screenshot Channel-Details.  You have entered 9.5 to .5m,  those are the values  prescaled in volts.  But you can see that it is looking for values in deg C.    You should enter the values of 999 and 0 which are the max and min for degC, the post-scale values.