Help on 4-20ma wiring

I’m using the dual channel 4-20ma Receiver and need some input on how to terminate wires from my M12 Connector. I have a separate 24V power supply that I’m providing to the sensor. The pin assignment from the Emmerson sensor is as follows:

Pin 1 (BN): L+ - 24V
Pin 2 (WH) OUT2 - Digital Output or active 4-20mA analog output
Pin 3 (BU): L- 0V
Pin 4 (BK): OUT1 - Digital Output

Attached are the example circuits. I can program the meter for PnP or NpN but I’m using C or D for Analog Output

If you have an external power connected then you can connect the 4-20mA wires directly to ncd transmitter and it should work. there are screw terminals marked as R(+) and B(-) for each channel.

Thank you for the feedback. Yes, I have external 24 Volt Power Supply. So I did try to wire in the white/black wires to the R+ terminals. This is a picture after I removed the black wire but it was wired to the second terminal from the left. I was reading 0.067ma so this was not accurate. From the drawings above it appears that the signal needs to be pulled to ground. Am I missing anything here?

if its reading below 4mA which means its an open connection and there is a wiring issue. if you measure current across your black and white wiring using a multimeter what do you read?

@Anil_Bhaskar Thanks for responding on this. For prosperity, I just wanted to close the loop on this as I figured it out. Per the drawing above the black wire needs to be pulled to ground. So White from Pin 2 is R(+) and B(-) is jumpered to the same black wire to ground on the external power supply.

1 Like