Calculating error with custom scaling DAQ from 4-20mA signal

[Dominic Maertens]

Hi,

I'm using the NI-USB 6009 DAQ hardware and Labview 10.0.1. I use the DAQ assistent to acquire a 4-20 mA signal, which works perfectly fine. I tested this with a waveform graph and the range of the machine corresponds with the current signal.

Now, when I use custom scaling in the DAQ assistent, after about 4,8mA the value of "x" is not changing anymore. I don't get an error or anything, it appears there is an upper limit. When I turn off the custom scaling, I see that there is nothing wrong with the signal in mA.

Can someone help me how to solve this problem?

Greets,

Dominic

dominic.maertens@lessius.eu

[Dominic Maertens · Accepted solution]

Nevermind, solved the problem. I didn't see that the signal input range had to be adjusted to the new scale. Once done, the problem was gone.