Hi there,
4-20 ma is standard for data acquisition from sensors in industrial environment.There are are many techniques like PWM and DAC for 4-20 ma current generation.But still i want to hear from automation experts for options about generating 4-20 ma.Is any micro controller which can directly output 4-20ma?
Dear peter,
I am a firmware developer and i have not seen transducers in working environment.but I want to make my doubts clear.
In above image you can see that 0 to 10 kv reprented by 0 to 20 mA.
parth pandya
Dear peter,
I am a firmware developer and i have not seen transducers in working environment.but I want to make my doubts clear.
In above image you can see that 0 to 10 kv reprented by 0 to 20 mA.
parth pandya
I did say there are always exceptions and also that the sensor would have to be powered by other means, all the sensors I have worked with for British Gas where loop powered and hence there could not be a zero current. I did not say it did not exist. but I am glad your on top of it, it has been quite a few years and I am sure there are many advances since I was in the field (Literally 
). Also my experience is based on the gas industry, looking at that DIN Rail mount module I would guess your in the Power industry, it looks to be some kind of power meter / remote sensor (I have not looked up the part, just guessing )
btw, TI has a number of chips designed to work directly with 4-20mA (or 0-20mA ) loops, you should check them out, but you can also create the loop driver with not much more than an op amp or two and a few other components
I also found this, it may be of interest: http://forum.arduino.cc/index.php?topic=134213.0
Peter
