How to use DAQmx Create Scale Linear

[ceilingwalker]

Hello. I have an output from an amplifier that is 10mV/V, that is being read by an USB-6002. The voltage range for this amplifier is 0-200 volts. I have been testing the DAQmx Create Scale Vi but do not understand how it works. I have looked at other posts here for answers but am still not clear how this works. To begin with, it says it uses the y=mx+b equation for it. I don't know what the slope is referring to unless it is the angle of the line. If someone might have an example that explains how this works, that would be awesome. I also tried looking at an example but couldn't find one. Thank you

[Bob_Schor · Accepted solution]

Here's a "seat-of-the-pants" explanation of y = mx + b.  If you think of "x" as the input, and "y" as the output, then you can consider "m" as the gain, and "b" is the offset, the output that you would read with zero input.  

If you think about this equation with respect to an amplifier, many are designed to have zero output when there is no input.  This means b = 0.  If you have a gain of 10mV/V (which I assume means that a 1V input would give a 10mV output, then m, usually called "the slope" (which is the slope of the input/output curve), would be .010/1 = 0.01.

Note you describe the range of your amplifier as 0-200V, so the output will be 0-2V, well within the ±10V of the USB-6002.

Bob Schor

[ceilingwalker]

Thank you for the explaining that. The USB-6002 provides a 0-5V signal to drive the amplifier. The amplifier itself has the 0-200V output. The amplifier has another connection on the front of it called "Monitor Voltage", that is what I am scaling, so that it can be read by the USB-6002. The amplifier on the front has a tag with "10mV/V" written over the BNC port where it has written the "Monitor Voltage". Again, thank you.