4-20mA analog input

[franco]

How do I use a 4-20mA input signal on the controllino?

[askat0061]

If you mean detecting that signal. Probably u can connect it to resistor and read the Voltage change as current changes.

[franco]

Thank u so much. I see it's same way we do with arduino

[visztani]

Hi,

I'm new in Arduino and Controllino...
Can you please post an example circuit and the size of the resistor? It would be a 24v dc pressure transmitter.

Thanks!

[miko-edv]

Hi,

we've had a similar job a few weeks ago: a laser for distance measurement, operating on 24V, gives 4-20 mA, that the Controllino shall read as analogInput.

The manufacturer offers an adaptor cabling with a 250 Ohm shunt between the laser's signal output and ground, to produce 0-5 V analog current. Should work on the Controllino's X1-port, but the mechanical attachment is not really good for single wires ... so the 24V ports are preferred.
So for our usage, we modified this resistor into 820 Ohm for 8-16V, and if you would take 1k Ohm, you will end at somewhere about 6-20V.

AnalogRead () now gets values between 80 and 550, that's a good enough range for our application.

Good luck
Michael

[visztani]

Thank you Michael for your explanation.

Did you extended it with any other circuit in order to protect Controllino against overvoltage / overcurrent (datasheet warns, the analog input max. current is <3mA )?

Thanks,
Peter

[miko-edv]

ooppss ... never cared about, never took values; it is working "as is", just a resistor between signal and ground.