Connect um330 and kc828 a16

[gtd0916]

yes, COLB direct use by 0-5v, if you want use by 4-20mA, you can add extend convert module, there are many 0-5v to 4-20mA small module on market, you can search it.
MQTT only use by ethernet. wifi is not stable.

Can I still read the current correctly if I connect a 250-ohm resistor across the + and − terminals?