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

Find current-voltage-resistance or power, 1.   Work out the  voltage for ...

1.   Work out the  voltage for the following arrangement of 1.5V cells : (to achieve a pass grade, solve problems with cells in series, parallel and series-parallel) 2.

RF design, Could you please answer this question with an explanation?

Could you please answer this question with an explanation?

Evaluate gm and pm for the asymptotic bode plot, Q. The loop gain of an ele...

Q. The loop gain of an elementary feedback control system(see Figure) is given by G(s)·H(s), which is 10/(1+s/2)(1+s/6)(1+s/50). Sketch the asymptotic Bode plot of the loop-gain fu

Compute the total capacitance with parallel connection, Compute the total c...

Compute the total capacitance with parallel connection: Three capacitors C 1 , C 2 and C 3 contain capacitance 20 μf, 15 μf, 30 μf, respectively. compute: 1. Charge on ea

Determine the two possible ssb am signals, Let the modulating signal m(t) b...

Let the modulating signal m(t) be a sinusoid of the form m(t) = cos 2πf m t, f m c , and let the carrier signal be cos(2πf c t + φc). (a) Determine the conventional AM signal,

Determine the required voltage at the high-voltage terminals, Q. A 20-kVA, ...

Q. A 20-kVA, 2200:220-V, 60-Hz, single-phase transformer has these parameters: Resistance of the 2200-V winding R1 = 2.50  Resistance of the 220-V winding R2 = 0.03  Lea

Draw a state diagram of 3-bit ripple counter, The block diagram for a 3-bit...

The block diagram for a 3-bit ripple counter is shown in Figure (a). Obtain a state table for the number of pulses N = 0 to 8, and draw a state diagram to explain its operation.

Characteristics of unijunction transistor, Characteristics of  unijunction...

Characteristics of  unijunction transistor: Characteristics : The static emitter characteristic of UJT at a given inter base voltage VBB in shown in fig. From fig., it is no

What are the three transistor configurations, Q. What are the three transis...

Q. What are the three transistor configurations?     The three configurations are common base (CB),common collector (CC) & common emitter(CE). The connection in which the base

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