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

Show maximum common-mode input voltage, Q. Show Maximum Common-Mode Input V...

Q. Show Maximum Common-Mode Input Voltage of amplifier? This is the maximum voltage that the two inputs can be raised above ground potential before the op amp becomes nonlinear

Gaussian derivatives, Gaussian derivatives Generate Gaussian kernels f...

Gaussian derivatives Generate Gaussian kernels for a given scale "sigma", and display the kernel. The size of the kernel should be floor(3*sigm)+1; (i) Write an m-file "

Compute the real power inductive load, Q. A 60-Hz, 440-V, three-phase syste...

Q. A 60-Hz, 440-V, three-phase system feeds two balanced wye-connected loads in parallel. One load has a per-phase impedance of 8 + j3  and the other 4 - j1 . Compute the real po

Opimization, I want to know latest optimization technique and algorithm for...

I want to know latest optimization technique and algorithm for modal reduction and pid controller design

High frequency induction heaters or magnetic fields, High Frequency Inducti...

High Frequency Induction Heaters or Magnetic Fields : If this type of equipment is in use, large currents may be induced in any nearby metallic object or circuit, which will in tu

Compute the efficiency of the transformer, Compute the efficiency of the tr...

Compute the efficiency of the transformer of Example corresponding to (a) full load, 0.8 power factor lagging, and (b) one-half load, 0.6 power factor lagging, given that the input

Show the complement representation, Q. Show the Complement Representation? ...

Q. Show the Complement Representation?   There are two types of complements for each number system. r's and (r-1)'s complement ex.             decimal

What is piconet, A collection of devices connected by Bluetooth technology ...

A collection of devices connected by Bluetooth technology in an ad hoc fashion.

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