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

Critical field circuit resistance and critical speed, Q.   Define and expla...

Q.   Define and explain the critical field circuit resistance and critical speed of a DC shunt generator.   Ans. The OCC and R - line for a DC shunt generator. As, R f is

Show voltage wave form of rlc series circuit, Q. The voltage wave form of F...

Q. The voltage wave form of Figure is applied to an RLC series circuit with R = 2, L = 2H, and C = 1 F. Obtain i(t) in the series circuit. (Note that the capacitor and inductor va

Show the overall output limitations of speed control, Q. Show the Overall o...

Q. Show the Overall output limitations of Speed Control? The overall output limitations are as shown in Figure. With base speed defined as the full-field speed of themotor at t

What is meant by blanking, a. Explain the following terms: (6) (i) Persi...

a. Explain the following terms: (6) (i) Persistence of vision (ii) Flicker in motion pictures b. What is meant by blanking? What is the need of blanking pulses? Compare th

Determine the function of time for the clock, Q. Determine the function of ...

Q. Determine the function of time for the clock? Given the block diagram for a 4-bit shift-left register shown in Figure (a), draw the output (Q 0 , Q 1 , Q 2 , Q 3 , and data

Phase shifter, Hi, I just finish writing my project literature review and ...

Hi, I just finish writing my project literature review and my supervisory asked me to add one part. This part is about Phase Shift. How phase shifters work? In Particular How the

Define magnetic field, Define Magnetic field The area around a magnet i...

Define Magnetic field The area around a magnet is known as the magnetic field and it is in this area that the effects of the magnetic force formed by the magnet can be detected

Digital storage oscilloscope, #question.draw the block diagram pf digital s...

#question.draw the block diagram pf digital storage oscilloscope and briefly discuss about each block

Rc coupled amplifier over a single stage, Q. What is the advantage of a two...

Q. What is the advantage of a two-stage overloaded RC coupled amplifier over a single stage one? What are it's uses? It is a frequently encountered configuration. Here, the tra

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