4-20mA analog input

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franco
Posts: 2
Joined: Mon Dec 02, 2019 11:00 pm

4-20mA analog input

Post by franco » Tue Dec 03, 2019 7:25 am

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

askat0061
Posts: 2
Joined: Thu Sep 19, 2019 6:39 am

Re: 4-20mA analog input

Post by askat0061 » Wed Dec 04, 2019 8:04 am

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

franco
Posts: 2
Joined: Mon Dec 02, 2019 11:00 pm

Re: 4-20mA analog input

Post by franco » Wed Dec 04, 2019 9:48 am

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

visztani
Posts: 2
Joined: Thu Sep 03, 2020 5:23 pm

Re: 4-20mA analog input

Post by visztani » Thu Sep 03, 2020 5:26 pm

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
Posts: 11
Joined: Thu Nov 28, 2019 3:14 pm

Re: 4-20mA analog input

Post by miko-edv » Fri Sep 04, 2020 9:16 am

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
Posts: 2
Joined: Thu Sep 03, 2020 5:23 pm

Re: 4-20mA analog input

Post by visztani » Tue Sep 08, 2020 9:21 am

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
Posts: 11
Joined: Thu Nov 28, 2019 3:14 pm

Re: 4-20mA analog input

Post by miko-edv » Tue Sep 08, 2020 7:38 pm

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

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