I have a loop with 3 MCP3428 4 channel 4-20ma receiver boards used to read 12 pressure transducers. Currently testing with one and four sensors. I constructed the electrical system in the diagram to power the boards, the sensors, and the Arduino off a DC 12 power supply but when I perform a test with the sensors feeding them 24 volts, I get ADC values below what 4ma would be. A quick check with a multimeter shows the sensors are outputting .2ma to 1ma. I figure this is a power issue as I tested the sensors with another Digi sensor reading device and they were outputting the expected values. I have the MCP3428 setup in 16-bit resolution, with the gain set to 2 and set to continues mode with a half second delay between reads. Can anyone tell me what I did wrong with powering the sensors? Also will my design in the diagram experience any voltage drop from running all 12 sensors? Sorry for any stupid mistakes and questions, new to this field and this product. all advice is much appreciated!
AWT-DC-Diagram.pdf (34.9 KB)