Answer / bnp

because there is voltage drop as per the length of conducting wire. but current has no drop

Answer / pradeep patil

Current 4-20 mA is prefered than voltage because:--
1)current signal can be carried to long distance without
drop in signal strength.
2)Less Electro Magnetic Interference effect in current
signal
3)no short crcuit spark happpens when signal cable
accidently short each other.
If your controller works on voltage (1-5 vdc) then 4-20 mA
can be easily converted in to voltage after connecting 250
ohm resistance accross signal cable as per ohms law.

Answer / himanshu

4-20 mamps is best choice because interference level is
minimum in current application where as in 0-10 V it is
comparatively high.Thus in using 4-20 mamps signal is
distortionless.

Answer / b0nz0

Most of the above answers are valid, but none have
mentioned security. If a current loop is broken then the
current will fall to 0.

Answer / yogi40

if we use voltage there there is noise interpretation
where as in current it wont happen
and current supports 2 wire connection,voltage doesnt
there will be drop in voltage when its feedback in current
such loss is very less

Answer / manuraj singh sengar

no, because voltage makes fluctuation & current remains
constant.

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