4-20mA Current Loop only used for analog signals?

[asimov]

Hi Everyone,
I am new to this current loop concept and was wonder if this
old/archiac config 4-20mA Current Loop is used only to pass analog signals
between 4 and 20 mA or the two ends of the range can be used as digital
signal signifying binary 0(4mA) and 1(20 mA).


Regards
Asimov

 

[crutschow]

Certainly you can use a current loop to transmit a two-level analog signal level and interpret it as two digital states. But it's overkill if that's all you are using the current loop for.

 

[FvM]

Analog current loop isn't archaic, it's very functional for a wide range of industrial applications. Digital current loop is still used in some applications, e.g. for MIDI (music instrument digital interface). For an overview https://en.wikipedia.org/wiki/Current_loop