I have recently purchased the 4-channel 4-20mA current Loop Receiver and have a wiring question. I have a 4-20mA sensor that expects 14-24VDC to be supplied on the sensor + connection and returns the 4-20mA signal on the sensor - connection. There is no “GND” connection. How would I hook this up to one of the channels of the 4-20mA current Loop Receiver? I see 6 screw terminals on the PCB, labeled from left to right G, IN1, IN2, G, IN3, IN4. Which pin will supply the onboard 16VDC power to the sensor, and which pin should receive the returned signal from sensor?
Thank you very much
Hi Chip, please indicate the part number you are using, I can point you to a wiring diagram that may be helpful.
On the product page, please click the “Resources” tab and scroll down. There are wiring diagrams on this page. I have tagged @Anil_Bhaskar on this thread in case there is more to it for your application. Bhaskar is our expert at 4-20mA.
That wiring diagram is extremely generic. It doesn’t show which pin should be used to deliver the 16VDC power to the sensor. Can you please explain which pins provide the loop power?
Perhaps this is how it works… You are supplying loop power on each IN<1-4> pin and expecting all returns to be connected to the G pins? And you are measuring the current as it leaves the IN<1-4> pins?
These are great questions for @Anil_Bhaskar who has been tagged in this thread.
@chip.bagwell I use this same board. If you look closely above the screw terminals you will see starting on the left G, IN1, IN2, G, IN3, IN4.
Connect your grounds for CH1 & CH2 to the first G, and your positive to IN1 and IN2. for IN3 and IN4 use the G in the center.
As confusing as it may sound, electrons actually travel from negative to positive.
There’s a great answer to this topic on Stack Exchange, please check it out:
I love these kinds of topics!