We use the ADS112U04IPW to measure 4-20mA current from a sensor. The value we get back from the ADS112U04IPW does not match our lab bench current meters. Error is about 4% and it is non linear. 2K resistor is equivalent to our customer's sensors. The LED is there so we can see if we have a good current loop. Display is a lab bench current meter.
We run the current through a 100 ohm resistor and measure the voltage drop across it. Checksum is good and results appear to be good but accuracy and linearity is bad so we must be doing something wrong.
raw=buf[1]<<8+but[0]
ma=2.048 * (rawhex/7FFF)*10.