SCADA
BASED MONITORING AND CONTROLLING USING ZIGBEE
ABSTRACT
Almost all the Industrial Data Acquisition and control systems today use
connection oriented concepts for interfaces. However, the variety of physical
shapes and functional commands that each cable or wire based system has also
raises numerous problems: the difficulties in locating the particular area
affected by the industrial parameter, the complexity in operation of the
system, the maintenance issue and so on. The control of sensitive industrial
parameters by using SCADA-based wireless technology has gained significant
industry and academic attention lately for the usability benefits and convenience
that it offers users. The control of the temperature of a room containing
chemicals and toxic gases the existing research has failed to provide a flexible
solution for controlling such conditions by connection oriented systems.
They have used cables and bulky equipment which require large amount of
space, high degree of the maintenance and are easily detoriated by moisture and
excessive heat.
Additionally, the Data acquisition and control techniques used so far have
imposed considerable computational burden and have not provided a consistent
and accurate results expected by the employees and their industries.
Keywords- SCADA, Zigbee, Monitoring, Controlling.
INTRODUCTION
Data Acquisition and Control Systems have gained much larger importance in
the Industrial field because of the rapid Technological advancement and
Security reasons. Whether it is an Industrial workshop, Defence go-down or experimental
lab of the power plant accurate monitoring of the parameters is the need of the
day. It could be the temperature, humidity, gas or light detecting sensor
waiting for our command to provide us with information about the measured
parameter of the particular area where they are installed. Advantage of the
system is that the engineer or worker not only can obtain accurate data about
the industrial parameters in remote area, but also there is no need to be physical
present over there. The amount of computation required to process the data
detected by sensors is much greater than that of the mechanical devices. Many
of those approaches have been implemented to focus in detection of the single
parameter such as temperature, gas, humidity or light by dedicating the entire
system to only one parameter.
FIG. 1 Block Diagram of Transmitter
TRANSMITTER
The Temperature sensor LM-35 is used for detecting the physical parameter
temperature of the particular device or the place where the product is stored
or manufactured. It produces an output voltage which is proportional to Celsius
temperature. It is a three pin device out of which the middle pin is used to
measure the output voltage. It transmits the data to microcontroller. The Light
Dependent Resistor (LDR) are used in places where there is need to control the
Intensity and level of light especially for protecting photo films and frames.
An LDR is made of semiconductor material. It has a high resistance because the vast
majority of the electrons are locked into the crystal lattice and unable to
move. Therefore in this state there is a high LDR resistance. As light falls on
the semiconductor, the light photons are absorbed by the semiconductor lattice
and some of their energy is transferred to the electrons. This gives some of them
sufficient energy to break free from the crystal lattice so that they can then
conduct electricity. This results in a lowering of the resistance of the
semiconductor and hence the overall LDR resistance. This data is given to microcontroller.
The GAS sensor MQ-6 can be used both in home and industry. It has a very
high sensitivity to gases such asLPG, Iso-Butane, Propane. Sensor is composed
of micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring
electrode and heater are fixed into a crust made by plastic and stainless steel
net. The enveloped MQ-6 have 6 pin , 4 of them are used to fetch signals, and
other 2 are used for providing heating current. The most important objective of
Infrared sensor is the Intrusion detection. This circuit uses an infrared (IR)
beam system to transmit the infrared signal that is of 38 to40 KHz signal when
interrupted by any device it will sounds an alarm and simultaneously it will be
given to the microcontroller for further process. When the beam is broken a
relay is tripped which can be used to sound a bell or alarm. Distances over 25
yards (8 to 10 meters) can be monitored. Humidity sensor HSY-220 is mostly used
in places where there is need to control the humidity such as food preservation
industries, clothing etc. This capacitive atmospheric humidity sensor consists
of a non-conductive foil, which is covered on both sides with a layer of gold. The
dielectric constant of the foil changes as a function of the relative humidity
of the ambient atmosphere and, accordingly, the capacitance value of the sensor
is a measure for relative humidity.PIC-Microcontroller 16F877A is a 40-pin IC.
It consists of five ports and built in A-D converter. Microcontroller converts
the analog signals to digital signals and then gives it to the Zig-bee
Transmitter via Zig-bee Interface. This is the monitoring function of the
project in the transmitter section. The controlling function comes into picture
when the obtained value crosses the set parameter value of the sensors. Then
the Microcontroller commands the Relay driver (ULN 2803) to operate the
respective device in accordance. Zig-bee is a technological standard created
for control and sensor networks. It operates in personal area networks (PAN’s)
and device-to-device networks. In the transmitter section the Zig-bee
transmitter is interfaced with the Microcontroller by using MAX232. All the
data collected by the sensors is given to Zig-bee transmitter via Microcontroller
for wireless transmission. IT transmits the data in the form of packets and
reduces the cost of wiring and cables. In accordance with the industrial
purposes it provides a very good alternative. The relay ULN 2803 is an
Integrated circuit chip with a high voltage/high current Darlington transistor
array. It takes signals from TTL, CMOS, PMOS which operate at low voltages and
currents. It is a relay of sorts for itself, switching on or off higher signal
on the opposite side.
RECEIVER
Fig.2 Block Diagram of Receiver
The receiver circuitry of the project is quite simple. The data transmitted
by the Zig-bee Transmitter is received by the Zig-bee receiver. This data is
then given to PIC Microcontroller via Zig-bee interfacing. The data is then displayed
on the LCD screen. If the parameter value crosses certain range of limit then
controlling action is performed by the controller. Initially it performs the operation
of alarming the Buzzer. The Buzzer alarm makes the operator alert. Buzzer or
beeper is a signalling device, usually electronic, typically used in
automobiles, household appliances such as a microwave oven, or game shows. It
most commonly consists of a number of switches or sensors connected to a control
unit that determines if and which button was pushed or a preset time has
lapsed, and usually illuminates a light on the appropriate button or control
panel, and sounds a warning in the form of a continuous or intermittent buzzing
or beeping sound. The word "buzzer" comes from the rasping noise that
buzzers made when they were electromechanical devices, operated from
stepped-down AC line voltage at 50 or 60 cycles. LCD is used to display the
numerical values of the parameters which are detected by the sensors. LCD
creates images on a flat surface by shining light through a combination of
liquid crystals and polarized glass. The technology differs from CRT because a
CRT uses a beam of electrons projected through a large glass tube to create images.
The topologies according to which the Zig-bee can be connected are star,
cluster tree, mesh etc. The devices which are connected to Zig-bee can be Full
Function Devices (FFD’s) or Reduced Function Devices (RFD’s).
Zig-bee operation takes place in two states: Active, Sleep. Active state is
used for receiving the data and Zig-bee is in sleep mode when the data
reception does not take place.
SOFTWARE DESCRIPTION
The Pic-Basic Pro Compiler is the easiest way to program the fast and
powerful Microchip Technology PIC-micro microcontrollers. Pic-Basic Pro converts
BASIC programs into files that can be programmed directly into a PIC-micro MCU.
The Pic-Basic Pro Compiler features: BASIC commands, direct and library
routine access to pins on PORTA, C, D, E, as well as PORTB, arrays, real
IF..THEN..ELSE and interrupt processing in BASIC. The Pic-Basic Pro Compiler
gives direct access to all of the PIC-micro MCU registers - I/O ports, A/D
converters, hardware serial ports, etc. - easily and in BASIC. It automatically
takes care of the page boundaries and RAM banks. It even includes built-in
commands to control intelligent LCD modules. The Pic-Basic Pro Compiler
instruction set is upward compatible with the BASIC Stamp II and Pro uses BS2 syntax.
Programs can be compiled and programmed directly into a PIC-micro MCU,
eliminating the need for a BASIC Stamp module. These programs execute much faster
and may be longer than their Stamp equivalents. They may also be protected so
no one can copy code. The Pic-Basic Pro Compiler is a DOS command line application
(it also works in Windows) and runs on PC compatibles. It can create programs
for any of Microchip's PIC-micro microcontrollers and works with most PICmicro
MCU programmers, including our EPIC Plus PICmicro Programmer.
The Pic-Basic Pro Compiler can also be used inside Microchip's MPLAB IDE.
This allows programs to be edited and simulated within Windows. More
information is on the MPLAB page.
Pic-Basic Pro Compiler now has limited support for the 12-bit core
microcontrollers and BASIC source-level debugging. If maximum compatibility is
need with the BASIC Stamp I, or would like to save a little money, or just
don't need all the extra features in PicBasic Pro, please take a look at standard
PicBasic Compiler.
APPLICATIONS
(a)Electric Power Generation, Transmission and Distribution
(b) Water and Sewage
(c) Buildings, Facilities and Environments
(d) Mass transit
(e) Manufacturing and Traffic signals
(f) Being an automated system less manpower is required
RESULT AND CONCLUSION
The importance of monitoring and controlling Industrial parameters lies in
building efficient SCADA based wireless technology. Its applications range from
providing security through intrusion detection to measuring important parameters
such as Temperature, Light Intesity etc. Given the amount of literature on the
problem of Data Acquisition and control and the promising recognition rates
reported, one would be led to believe that the problem is nearly solved. Sadly
this is not so. A main problem hampering most approaches is that they rely on
several underlying assumptions that may be suitable in a controlled lab setting
but do not generalize to arbitrary settings.
Several common assumptions include assuming absence of dust particles in
the atmosphere of the room and ambient lighting conditions. In addition,
recognition results presented in the literature are based on each author’s own collection
of data, making comparisons of approaches impossible and also raising suspicion
on the general applicability. To ameliorate these problems there is a need for
the establishment of a standard database for the evaluation and comparison of
techniques. SCADA-based wireless technology has gained significant academic and
commercial interest lately with the goal of allowing workers and engineers to control
sensitive industrial parameters with Zigbee modules. We are presenting an intelligent
gesture interface for reliably commanding sensors and relays through a
user-defined language.
FUTURE SCOPE
Data can be sent in a bi-directional way. The ultimate goal of this project
is to develop a technology to aid in the further development of bi-directional
communication between a PC and a remote robot. A user should be able to send
data in a full duplex mode i.e. transmit and receive simultaneously. Data can be
broadcasted. Broadcasted data can be sent which will enable data to reach
multiple recipients. We can use SCADA to manage any kind of equipment. Typically,
SCADA systems are used to automate complex industrial processes where human
control is impractical systems where there are more control factors, and more fast-moving
control factors, than human beings can comfortably manage.
REFERENCES
(1)IEEE Recommended Practice for Data Communications Between Remote Terminal
Units and Intelligent Electronic Devices in a Substation, IEEE Std 1379-2000(Revision
of IEEE Std 1379- 1997),21 September 2000
(2)Chan, E.-K., Ebenhoh, H., The implantation and evolution of a SCADA system
for a large distribution network, Power Systems, IEEE Transactions on,
Volume:7, Issue:1, Feb.1992
(3)Aung Naing Myint, “Design and Application of SCADA Based Control System
for Filling Process (Interfacing and Monitoring)”, MTU, Mandalay, Myanmar,
November 2007.
(4)Prof. James Trevelyan, “SCADA System Development-Design Study”, Dept. of
Mechanical & Mat. Engineering, the University of Western Australia, June
2000.
(5)Michael P. Ward, An Architectural Framework For Describing Supervisory
Control And Data Acquisition (SCADA) Systems, by Publishing Monterey, California,
September 2004.
(6)Microchip Technology, ”PIC 16F87X DATA sheet 28/40-pin 8-bit CMOS FLASH Microcontrollers”,
in USA,2001. Available:http://www.microcontroller.com/catalog/database.
(7)Gareth Talamini, Operator Interface Design for Industrial Control, Submitted
for the degree of Bachelor of Engineering (honours) In the division of
Electrical and Electronic Engineering, October 2004.
(8)Thomas L. Floyd, Electronic Devices Volume 2, Fourth Edition, Printed by
Prentice-Hall Inc, A Simon and Schuster Company, New Jersey,1996
(9)Controlling of large Data Acquisition System using an Industrial SCADA system
using Stefan Koestner,Member,IEEE,on behalf of the LHCb Online Group
