Unlike the 2- and 3-wire transmitter representations shown in Figure 2, the 4-wire circuit has separate paths for the power current and signal current. Also, the 4-wire receiver does not share a ...

In The basics of 4-20mA current loop transmitters, I discussed the basics of 4-20 mA transmitters, a popular communication method to and from field elements in factory automation and other industrial ...

Use of 4-to-20-mA current loops involves more than just a simple series connection between sensor, display, and power supply. The point where a sensor takes a measurement is, at times, many yards away ...

Many industrial and control applications use analog current loops as the physical link for measurements and actuator control. Although several ranges are used, the most popular is still the 4- to ...