2 Channel Industrial IoT Wireless 4-20mA Current Loop Receiver (ncd.io)
Hi. I can successfully connect 2 wire sensor on channel 1 like the wiring below as instructed.
Reading looks good.
And then, when I was trying to connect the same sensor on channel 2, I made the wiring below.
However the current drops below 4mA and the incoming data is as below,
Could you help advise me the correct wiring for both channels, when wiring the 2-wire sensor and 3-wire sensor respectively? Thanks.
You have the correct wiring.
The analog input has a +/-2% tolerance ( due to onboard parts and analog conversion).
We always recommend using raw ADC values to convert sensor data into real-world data.
If you need help with that, let me know, and I can guide you.
Good to know the wiring is correct.
Sorry I don’t get it. Do you mean 2% of 20mA => gives +/- 0.4mA tolerance so 4.0 - 0.4 = 3.6mA which is still a acceptable figure?
Please advise your method on using ADC values to do conversion. I have been using a 4-20mA sensor to measure 4000mm distance in my project. During my earlier testing on channel 1 & channel 2 , the sensor should be at 4mA (0mm) so the result of channel 2 (3.6mA) shocks me.