I'm sure that one advantage of a mA signal versus a voltage signal is noise immunity. Are there any other significant advantages or disadvantages?

 

If you lose your signal on a 4-20 mA you will have 0 mA and can determine that there is a problem and that the output isn't just 0%.

 

4-20 can always be converted to voltage using a resistor. For example, if the transducer has a 24 V supply, use a 250 Ohm resistor to create a 1-5V signal.

 

With long cable runs you will get voltage drops on the cables thus providing wrong values coming from the field. Current signals don't suffer from this problem............

 

Hello

0-10v signal can only be used up to 100 meters distance with a specified sized of wire,if you need a long run cable you should use 4-20mA signal instead.


Alvin "KIDLAT" Cipriano

 

hai,

I feel the following are advantages of using mA signal

a.) Noise immunity
b.) Lower Installation Cost
c.) Can be used in Hazardous area
d.) Less wire resistance

regards,
S. ELAVAZHAGAN.
Engineer - I & C.
TCE Consulting Engineers Ltd.

 

Other than the obvious advantages of 4-20, you should consider the resolution of the A/D conversion. 0-10 is usually better after the conversion.

 

Two pros for 0-10vdc:

voltage readings are easy to take than current readings when troubleshotting.

0-10 devices tend to be more common.

I usally go with 0-10vdc, just because of the fact it will be easier for the electricans.