40520130101001

Journal of Electronics and Communication Engineering & Technology (JECET)ISSN
2347–4181 (Print), ISSN 2347 – 419X(Online), Volume 1, Issue 1, July-December(2013)
1
FULL-DUPLEX UART APPROACH OVER POWER LINE USING
FAMPLC TECHNIQUE
Alireza Nazem1
, Mohd Rizal Arshad2
1&2
(Underwater Robotics Research Group (URRG), School of Electrical and Electronic
Engineering, Universiti Sains Malaysia, NibongTebal, Pulau Pinang, Malaysia)
ABSTRACT
FAMPLC is an approach to real time bidirectional Power Line Communication in
remotely controlled applications combining the voltage’s frequency and the current’s
amplitude modulations [1]. The square-wave frequency modulated AC Power in one end
called “the server”, supplies the “receiver node” in another end using a bridge inverter. Data
in this mode is carried by the pulse-width and the frequency values. Data transmission from
the receiver node to the server is by use of an active resistor as a dummy load. A Thevenin
Equivalent Converter (TEC) circuit is embedded in the server to derive the equivalent voltage
from the current means. An UART port was successfully established over a dedicated power
supply and a remote application as an extended I/O port in ROV application. The result of a
full duplex transmission for the remote I/O is also presented.
KEYWORDS: FAMPLC, UART over power-line, full-duplex transmission, Frequency and
Amplitude combined Modulations
1. INTRODUCTION
FAMPLC is a non-superimposing method in which the power-line is utilized as a
communication platform using its parametric values such as Voltage, Current, frequency and
duty cycle. A DC to AC inverter is used as the server module to transmit the data over the
power line [2].Since the consumer draining current in the regulated DC line is not
proportional to the unregulated incoming AC voltage, a full duplex communication may be
established between the power supply and the consumer based on each specific layer.Despite
the Frequency Modulated Power Supply (FMPS) used in this research to transmit data from
the server module to the consumer node, current mode circuitthat is employedto transmit vice
versa are described as the circuit whose input and output signals are currents rather than
voltage signals [3].Fig. 1 illustrates the genericconcept of this technique for a UART
communication.
In 2009, Industrial Power Line Communication (IPLC) was presented [4]. This
technique uses the power cables of the DC link as transmission medium and thus does not
Journal of Electronics and Communication Engineering &
Technology (JECET)
ISSN 2347-4181 (Print)
ISSN 2347-419X (Online)
Volume 1, Issue 1, July-December (2013), pp. 01-09
© IAEME: http://www.iaeme.com/JECET.asp
JECET
© I A E M E

2347–4181 (Print), ISSN 2347 – 419X
require any other cable. It was achieved by a coupling unit that couples the data onto the
power cables, resulting in reduction of the cabling effort considerably.
power line communication methods such as the Frequency Shift Keying (FSK) as
modulation technique [5], the maximum copper length is limited to typically not longer than
500 meters. In medium voltage power system, multip
required to compensate the signal drop for longer distances [6
power line transmission over 1500 meters of copper cable was successfully achieved.
Fig. 1: The fundamental concept of FAMPLC communication
2. APPROACH AND METHODS
2.1 FM transmission approach
In FAM, a DC to low frequency (<
transmitting data by changes in the Frequency and the duty cycle of the inverted
The linear characteristics of a multiply conductor cable in base frequencies allows longer
distance data transmission [7]. The supplying sour
components for FM transmission over the supplying power.
Fig. 2: DC to frequency modulated AC inverter block
nd Communication Engineering & Technology (JECET)ISSN
419X(Online), Volume 1, Issue 1, July-December(2013)
2
power cables, resulting in reduction of the cabling effort considerably. In comparison to other
power line communication methods such as the Frequency Shift Keying (FSK) as
], the maximum copper length is limited to typically not longer than
500 meters. In medium voltage power system, multiple repeaters with dedicated ID
nal drop for longer distances [6]. In this research, full duplex
fundamental concept of FAMPLC communication.
APPROACH AND METHODS
FM transmission approach
FAM, a DC to low frequency (<1 KHz) AC inverter embeds the means of
transmitting data by changes in the Frequency and the duty cycle of the inverted
]. The supplying source is called, FAM server. Fig.
components for FM transmission over the supplying power.
to frequency modulated AC inverter block.
December(2013)
In comparison to other
power line communication methods such as the Frequency Shift Keying (FSK) as a robust
], the maximum copper length is limited to typically not longer than
peaters with dedicated IDs are
]. In this research, full duplex
) AC inverter embeds the means of
AC power.
ce is called, FAM server. Fig.2 shows the

3
To extract the data means from the modulated AC power, a pulse-width reading
process is performed using an embedded counter in the receiver’s circuitry. This is also done
for the extraction of the data from the current means by the receiver node’s circuitry. The
resolution of counts is dependent to the clock speed of the counter. In higher frequencies
since the pulse-width interval is reduced, clock gating process may be applied in order of
maintaining the accuracy [8].
2.2 AM transmission approach
A dummy active resistance circuitry as shown in the fig. 3 is considered to overlay
the data as a current layer besides existing consumers. The Mayer-Norton circuit by use of a
bipolar or a uni-junction transistor is considered for this model. The Norton equivalent
circuitry [9-10] provides a rail to rail signal conversion from the desired signal that is
amplified and shifted over the zero crossing level.Since the value of the variant resistant may
drop too low, the transistor is chosen from medium power family thus the bandwidth, and the
pulse responds in common collector/drain configuration is considerably crucial.Notable that
for an errorless AM transmission using the abovementioned dummy load, a regulatory circuit
to stabilize the voltage for other consumers is required right after the active resistance in
order to prevent from capacitive damping distortion to the sharp rising and falling pulses
edges.
Fig.3: Active resistance as the dummy load.
Notable that for an errorless AM transmission using the abovementioned dummy
load, a regulatory circuit to stabilize the voltage for other consumers is required right after the
active resistance in order to prevent from capacitive damping distortion to the sharp rising
and falling pulses edges. A Thevenin Equivalent Converter (TEC) in the server circuitry as
illustrated in fig.4 is employed to generate the substitutable voltage means of the draining
current [11].

2347–4181 (Print), ISSN 2347 – 419X
Fig.4: The embedded
To overcome the pulse-width losses due to sharp rising and falling edges the TEC
circuitry can be designed using either fast operational amplifiers or differential current
sensing comparators [12].
2.3 Two-Port Network analysis
In TL theory [13], a common way to
fig. 5, is to use the transmission matrix, also known as the ABCD matrix.
Fig.5
),( 22 IV as functions of ),( 11 IV , can be expressed as in
backward transmission matrix.
2
2
I
V
4
embedded TEC circuit in the server unit.
width losses due to sharp rising and falling edges the TEC
analysis
], a common way to present a Two-Port Network (2PN
, is to use the transmission matrix, also known as the ABCD matrix.
.5: The concept of a 2PN model.
, can be expressed as in equation 1. bT in (1) is referred to the
1
1
1
1
1
1
1
2
2 1
I
V
T
I
V
A
B
C
D
BCADI
V
D
B
C
A
b=
−
==
−
(1)
December(2013)
width losses due to sharp rising and falling edges the TEC
Port Network (2PN) as shown in
) is referred to the

5
2.4The Transfer Functions
Given 2PN in Fig. 5, the ABCD parameters allow us to calculate the transfer
functions as in equation (2) and (3) [14-15-16]:
)/(/)( 2 SLSLLSS DZZCZBAZZVVfH +++== (2)
SSLSR ZDZZCZBfH /)()( ++= (3)
)( fHS and )( fHR are the FM and AM transfer functions respectively. SZ is proportional to
the dynamic characteristics of the cable such as its umbilical form and/or its released length.
Since both LZ and SZ are independently variables, therefore, a sustainable data transmission
is obvious to be only proportional to BCD current dependent coefficients in AM mode from
the receiver node to the server.
3. UART OVER POWER-LINE
According to fig. 2, the bridge driver is influenced by the processor’s control pin to
generate proportional switching sequences for a square-wave AC. This can be any kind of
data such as ASCII codes for an asynchronous serial communication. Since FAMPLC has
been initially introduced for bass frequencies, in order to achieve high baud rates, a
compensation block has to be added to each layer of transmissions. The Total Harmonic
Distortion (THD) [17] in higher frequencies depends on the dynamic characteristics of the
transmission layer. The distortion analysis for transmission model shown in fig. 6(a) for an
FM transmission can be expressed as in equation 4.
( )tsts
C eKseKs
C
tV 21
2 21122
0
1
)( +=
ω
(4)
Where:
)1( 2
001 −−−= sss ζωωζ
)1(
2
002 −+−= sss ζωωζ (5)
And:
L
CrL
s
2
=ζ (6)
is called the exponential damping ratio for the server’s transmission line. 1K and 2K are
achievable from two equations of the initial conditions of )0(Ci and its time base derivative.
Fig. 6(b) demonstrates the consequent effect to the sharp rise and fall edges of the power
pulses.

2347–4181 (Print), ISSN 2347 – 419X
Fig. 6: a) The transmission model for UART
On the other hand, the AM distortion
the expression 7.
Si
The first and second terms in (
transmission. nRi ′ And AMi are the system draining current and the dummy load current
respectively. AMi is used to carry the data means over AM. Fig.
test signal in 1000 meters of copper cable.
Understanding the edge distortions leads to an overcoming compensation thus, an errorless
transmission. Fig. 8 demonstrates a real time full duplex transmission concept in an ROV
application.
6
(a)
(b)
transmission model for UART b) The consequent pulse edge distortion
On the other hand, the AM distortion analysis for current mode transmission results in
AMR
vLv
ii
dt
tdiCr
dt
tidLC
n
+++= ′
)(
2
)(
2 2
2
(7)
The first and second terms in (7) present the distortion interval of the AM
are the system draining current and the dummy load current
y the data means over AM. Fig. 7 shows the TEC output of a
0 meters of copper cable. SV is the amplified voltage drop across
8 demonstrates a real time full duplex transmission concept in an ROV
December(2013)
The consequent pulse edge distortion
analysis for current mode transmission results in
(7)
distortion interval of the AM
are the system draining current and the dummy load current
7 shows the TEC output of a
the amplified voltage drop across SR .
8 demonstrates a real time full duplex transmission concept in an ROV

2347–4181 (Print), ISSN 2347 – 419X
Fig. 7: The TEC output illustrating the equivalent voltage means of the total current
distortions, system current consumption and the active resistance overlaid current.
Fig. 8: The result of a real time full duplex t
4. CALIBRATION
A calibration sequence may be needed to overcome the consequential errors due to
the cabling distortion. This is done using a specific pulse
transmission and depends on the importance of commands. For
”with the frequency “f” and the duty cycle
sequential processor as the reference
enables the CPU for a calibration process to determine the width loss.
7
The TEC output illustrating the equivalent voltage means of the total current
The result of a real time full duplex transmission over the power line.
the cabling distortion. This is done using a specific pulse-width once or in ahead of every
depends on the importance of commands. For example, pulse
and the duty cycle “D” is defined in boot up sequence of each
reference. Comparing the received pulses with wP by
the CPU for a calibration process to determine the width loss.
December(2013)
The TEC output illustrating the equivalent voltage means of the total current
ransmission over the power line.
width once or in ahead of every
pulse-width “ wP
in boot up sequence of each
by each party

8
5. CONCLUSION
Understanding the generic concept of the novel technique of FAMPLC theory yields
to establish a real time full duplex UART communication over a dedicated power line for
control and monitoring of a remote application.It thus eliminate the need of fiber-optic
materials and transducers that require serious maintenance and high cost in applications such
as Remotely Operated vehicle (ROV).Table 1demonstrates some economical comparison
between the herewith discussed technique using a copper cable and the conventional optical
method known as a hybrid cable (Copper & fiber-optic).
Table1. Economical comparison of the fibre optic and copper cables
Cable
(100 meters)
Hybrid Copper
Cost (USD) >700 <400
Winch radius (cm) >40 <30
Weight (Kg) >30 <20
REFERENCES
[1] A. Nazem, M. R. Arshad, Composite video transmission as current overlay using
powerline concept of the FAMPLC, Proc. IEEE Symposium on Industrial Electronics
and Applications, Langkawi, 2011, 279-283
[2] G.Ramachandran, T.MuthuManickam, B.SuganyaAbiramavalli, T.Sheela,
ArunKumarMadhuvappan andL.Vasanth, Study and implementation of green power
in campus environment, International Journal of Electronics and Communication
Engineering and Technology, Vol. 3, Issue 1, 2012, 325-331
[3] R. K.Tiwari, S. Kumar andG. R. Mishra,A study on techniques of improvements in
current mirrors using Wilson scheme, International Journal of Electronics and
Communication Engineering and Technology, Vol. 3, Issue 2, 2012, 56-62
[4] Alexander V., Stefan S., Dongsheng Y. andKarl-Heinz W., Industrial powerline
communication for machine tools and robotics,German academic society for
production engineering, Vol. 2, 2010, 295-305.
[5] Rakesh C. P., Noise measurement in low-voltage powerline for modem design and
Serial data acquisition,Proc. Int. Conf. on Information, Computing and
Telecommunications, Dhaka, 2007, 113-6.
[6] Duckhwa H., Younghun L. andYoungdeuk M., A study on the composite power line
communication network,international journal of communication and networking, Vol.
56, 2009, 547-548.
[7] M. Hasheminezhad, M. Vakilian, T.R. Blackburn and B.T. Phung, Direct introduction
of semicon layers in xlpe cable model,Proc. International Conf. on Power System
Technology, Chongqing, 2006, 1-7.
[8] K. M.Quadry, S. A.Sattar and K. S.Rajan, Design of 16 bit low power processorusing
clock gating technique,International Journal of Electronics and Communication
Engineering and Technology, Volume 3, Issue 3, 2012, 333-340

9
[9] Tianyu An, Research on illed-conditioned equations in tracking thevenin equivalent
parameters with local measurements, Proc.IEEE Conference on Power System
Technology, Beijing, 2006, 1-4.
[10] Reza C. andOmid H., Differential current conveyor based current comparator,
International Journal of Electronics Communications AEÜ, 2011, 949-953.
[11] A. Nazem, 2008. Free Level Threshold Zone (FLTZ) logic for mixed analog – digital
closed loop circuitry, Master thesis, school of Electronic and Electrical Engineering,
Universiti Sains Malaysia, 2008.
[12] D. N. Kapadia and P. P. Gandhi, Design and simulation of high speed CMOS
differential current sensing comparator in 0.35µm and 0.25µm technologies,
International Journal of Electronics and Communication Engineering and
Technology, Volume 3, Issue 3, 2012, 147-152
[13] Stefano G, andThomas B., A novel approach to the modelling of the indoor power
line channel-part ii: transfer function and its properties,IEEE Transaction on Power
delivery, Vol. 20, No 3, 2005, 1869-1878.
[14] Petr M., Jiří M., Martin K. and Miloš O., Power line cable transfer function for
modelling of power line communication system, Journal of Electrical Engineering,
Vol. 62-2, 2011, 104-108.
[15] Richard R. S. and Mohammed S. G., Introduction to Electronic circuit design, int. ed.
Pearson Ed. (New Jersey: Prentice Hall, 2003) 15-17.
[16] Summerson S. R., Equivalent Circuits and Transfer Functions, Rice University,
department of Electrical engineering, Technical report, 2009.
[17] Y. Liu, H. Hong, and A. Q. Huang, Real-time calculation of switching angles
minimizing THD for multilevel inverters with step modulation,IEEE Transaction on
Industrial Electronics, VOL. 56, NO. 2, 2009, 285-293.

40520130101001

Recommended

Recommended

More Related Content

What's hot

What's hot (18)

Similar to 40520130101001

Similar to 40520130101001 (20)

More from IAEME Publication

More from IAEME Publication (20)

Recently uploaded

Recently uploaded (20)

40520130101001