Signal in hart protocol, Electrical Engineering

Assignment Help:

What is the significance of "4-20 mA" signal in hart protocol?

Ans) the HART protocol is an old Frequency Shift Keying way of distribution data, typically from highway sensors. This is a very old standard by today's standards there are so much better ways to send data. Of course, 4-20 ma loops are even older, dating back over 50 years, and still in common use. Must be something good about it - it is easy.

 

4-20 ma loops are a way to send an analog value, like temperature / position, over a pair of wires. It is easy on the surface, 4 mA is the minimum, and 20 mA is the maximum of the range. The cool thing about this is that it is stable current, not a voltage, so line resistance does not matter. Anything, constant current looks like an open circuit, so it is supposedly immune to noise (by in reality it still has noise pickup problems). Though, why not 0 to 20 mA the cool thing is you can power the remote sensor. You are running a current by the remote you have a voltage at the driving end why not use some of that power to run the electronics in the sensor? Thus, if the sensor pulls less than 4 ma and you make the range 4-20, you always have sufficient current to power the remote at the similar time.

 

 


Related Discussions:- Signal in hart protocol

Zero flag - registers , Zero Flag - Registers If the  result of any  a...

Zero Flag - Registers If the  result of any  arithmetical  or logical  operation in the accumulator  is zero i ,e  all the bits  of accumulator  ( with  some exceptions )  are

What do you mean by dial pulses, Q. What do you mean by Dial Pulses? D...

Q. What do you mean by Dial Pulses? Dial Pulses: Dial pulsing (many times known as rotary dial pulsing) is the method originally used to transfer digits from a telephone set

Linear time invariant, A LIT (linear time-invariant) system, impulse respon...

A LIT (linear time-invariant) system, impulse response h [ n ], is described by: (a) Show the block-diagram representation for this FIR filter (only use multiplier, adder

Explain the working principle of an opto coupler, Q. Explain the working pr...

Q. Explain the working principle of an opto coupler? When it is necessary to block the voltage between one electronic circuit and another, and transfer the signal at the same t

Find the speed of the motor, Q. A 10-kW, 230-V shunt generator, with an arm...

Q. A 10-kW, 230-V shunt generator, with an armature-circuit resistance of 0.1  and a field- circuit resistance of 230 , delivers full load at rated voltage and 1000 r/min. If the

Bad workmanship, Bad Workmanship Bad workmanship contributes important...

Bad Workmanship Bad workmanship contributes importantly towards increasing distribution losses. Efforts should, thus, be made to have the best probable workmanship. In this co

What is segment displays, Q. What is Segment displays? Seven-segment di...

Q. What is Segment displays? Seven-segment displays are the most commonly used numeric display devices, while 10- and 16-segment (starburst) display devices are also available.

Show advantages of oscillators, Q. Show Advantages of Oscillators? Alth...

Q. Show Advantages of Oscillators? Although oscillations can be produced by mechanical devices (e.g. alternators), but electronic oscillators have the following advantages:

Define amplification factor, Q. Define amplification factor? Amplifica...

Q. Define amplification factor? Amplification factor  μ It is the ratio of the drain -source voltage (ΔVDS) to the change in the gate to source voltage (ΔV GS ) at constan

Equivalent circuit of a polyphase induction machine, Equivalent Circuit of ...

Equivalent Circuit of a Polyphase Induction Machine The inductionmachinemay be regarded as a generalized transformer inwhich energy is converted and electric power is transferr

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd