Analog Voltage ADC Vs Current loop receiver

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Derby

New Member

• Apr 16, 2018

• #1

At one place i have 0-10v ADC converter and other place I have 4-20mA, For knowledge terms as well as for building Industrial based project which one is much more effective to use? As 4-20mA is very old and effective concept for reading the signal at long distance but 0-10V ADC is has high communication rate but still confused which on is most effective and long lasting
Your Expertise advice will be helpful?

 

Last edited: Apr 16, 2018

S

schmitt trigger

Well-Known Member

Most Helpful Member

• Apr 16, 2018

• #2

The 4-20 mA standard is so ubiquitous and has stood the test of time so well for a simple reason: it does its intended job very, very well.

Plus there are literally hundreds of compatible transmitters and receivers.

 

dknguyen

Well-Known Member

Most Helpful Member

• Apr 16, 2018

• #3

you answered your own question. Which is better? A hammer or a saw?

 

D

Derby

New Member

• Apr 17, 2018

• #4

dknguyen said:

you answered your own question. Which is better? A hammer or a saw?

Click to expand...

So that means i can use any one of them for far distance ??

 

D

Derby

New Member

• Apr 17, 2018

• #5

Is there any difference between both which will help me to understand it properly ?

 

dknguyen

Well-Known Member

Most Helpful Member

• Apr 17, 2018

• #6

Derby said:

So that means i can use any one of them for far distance ??

Click to expand...

Well what do you need more? Distance (more noise immunity and no voltage drop over long cables) or high speed? Because at some point (long enough distance or high enough speed), one becomes better than the other. It's a trade off.

0-10V is also simpler in theory with potentially lower power consumption. But current loop can let you do funny things like feeding power over the same cables that send the signal (as long as the device uses less than 4mA to power itself) which means less wires which is always good but particularly good for long distance.

 

Last edited: Apr 17, 2018

crutschow

Well-Known Member

Most Helpful Member

• Apr 17, 2018

• #7

The 4-20mA current-loop inherently suppresses any common-mode noise, which is common in an industrial environment.
To use the ADC over any significant distance would require sending the signal differentially and using a differential amp, such as an instrumentation amp at the receiving end, to suppress this noise.

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Apr 17, 2018

• #8

Nothing is wrong with an ADC receiver. At the receiver (PLC), you have a resistor that converts the current to a voltage. There is nothing wrong with that.

What you don't want to do is transmit analog voltages long distances.

 

unclejed613

Well-Known Member

Most Helpful Member

• Apr 18, 2018

• #9

in a current loop, all the devices are in series, so the current through them is the same, even with long runs of cable.