21-11-2012, 04:50 PM
Remote Industrial Data Acquisition, Managing snd Control System
Remote Industrial Data Acquisition, Managing &Control System (SCADA).docx (Size: 66.28 KB / Downloads: 27)
ABSTRACT
Phase-I
of the project involves the acquisition of data from different sensors and logsthis into a personal computer having data base in visual basics where the data isdisplayed for monitoring. Also set value defined which compares the actual data withthe set values and generates commands to control the controlling elements (in ourcase relays) accordingly. So by the automatic control is achieved. The invention of the remote control facilities the people in ordered to control their electrical andelectronics devices without manually operating them. Besides controlling theequipment at the place of installation we have uploaded this on the internet to monitorand control the equipment anywhere in the world.
Phase-II
of the project involves the controlling and monitoring of different electronicdevices using GSM
How It Works
The whole project will be consisting of two Phases
Phase-I
It will be consisting of Sensor-Based Data Acquisition, Monitoring & ControlSystem.
Phase-II
Design and Implementation of GSM-Based Monitoring & Control System.
The Phase-1 consists of six main parts1. Sensors2. A\D (ADC0809)3. Microconntroller (AT89C51)4. Max 2325. ULN28036. SoftwareIn Phase-1 Temperature sensor is used which is an analog transducer it produces avoltage according to the temperature. it produces 10mV/1C,it can measuretemperature from(-50C to 150)voltage generated by the LM35 is analog this voltageis given to the analog to digital converter, the A\D converter converts this analogvoltage to 8 bit binary number by Sampling, Quantization and Coding.The A\D converter is a 28 pin IC. It can take 8 analog inputs, one at a time, and cangenerate 8 bit binary number according to it. There are three pins 23(ADDR2),24(ADDR1), 25(ADDR0), which are used to multiplex the inputs to the A\Dconverter.The program in the microcontroller sends the different combination to the addresspins of the A\D converter to select the input to the A\D converter. when input isentered the A\D converter, the six no.(start)pin of the A\D converter is made high bythe controller, to start conversion from analog to digital. During conversion processmicrocontroller monitors the EOC (End of Conversion) pin which is #9 of the A\dconverter. When it becomes high mean the analog to digital conversion is completed.After it microcontroller sends high to OE (Out put Enable) pin of the A\D converter.This pin is used to get out the digital information from the A\D converter this digitaloutput is given to the port#2 of the microcontroller. The microcontroller gets thisdigital number and converts into corresponding temperature. This temperature valueis then sends to the PC through serial port using Max232.Max232 IC is used to make compatibility between TTL and RS232standard.TTLmeans transistor to transistor logic it is used in the IC mean ICs required +5v or -5v tooperate.RS232standard used in serial port of the PC. It uses high value for logic0 and1.it uses -3 to -25 for logic 1 and 3 to 25 for logic 0.Max232 has two sides one is TTLand other isRS232.TTL side is connected to ICs and RS232 side is connected to PCserial port. By this compatibility between to standard is made.There is software in the PC which is made by using Visual Basic. All the temperaturereadings from different sensors are logged into the software automatically. Thesoftware receives all the values from sensors after every second. The software showsthe current temperature and previous temperatures of all the sensors. There is also aset point. Upper limit and lower limit options in the software. We can set thetemperature in the software in the set point option for all the sensors invidually.whenthe actual temperature coming from the sensors is greater than the set point then thesoftware itself generated a command and send it to the microcontroller throughMax323.the relays are attached to the pot#1 of the microcontroller. according to thesignal from the PC microcontroller generated logic high to its pin of port#1.at port #1
of the microcontroller a relay driving IC ULN2803 is connected, this IC is used todrive the relays. This has Darlington pairs in it. It provides ground path to energizethe coil of relay. And which we want to control is attached to the relays. Relay hasthree contacts, common, normaly open, normally close. when p1.0 is made high bythe signal from PC then pin#1 of the ULN2803 is also high by this relay attached topin#28 of ULN2803 is energized because current flows through its coil, and itscontacts changes from normally closes and load attached to it become on or off according to its connections with relay