02-29-2016 05:02 AM
Hello ,
I am using LabVIEW 2013 version.
I have a sensor to acquire pressure. Pressure sensor gives out 4 to 20mA current output corresponding to pressure . This is a linear conversion.
I am using DAQmx Scale VI (linear) before I configure the channel. So automatically I get the scaled converted output on DAQmx Read VI.
But I have another force sensor. It s conversion equation is y= ax (cube) + bx( sqaure) +cx+d .
3rd order polynomial equation. y will be force output and x will be current read from sensor and a,b,c,d are co-efficients.
How to do this with Create Scale VI.
I tried but there is forward , reverse co-efficients. to be used. I require help on this as to how to implement my scaling.
Thanks
02-29-2016 05:30 AM
Did you look at the 'help' for the DAQmx Create Scale VI?
Creates a custom scale that uses an nth order polynomial equation. NI-DAQmx requires both a polynomial to convert pre-scaled values to scaled values (forward) and a polynomial to convert scaled values to pre-scaled values (reverse). If you only know one set of coefficients, use the DAQmx Compute Reverse Polynomial Coefficients VI to generate the other set.
03-01-2016 11:36 AM
You can also scale it yourself by reading in the current and using basic math operations from the numeric pallete