Design Of Five Floors Elevator With SCADA System Based On S7200 PLC

International Journal of Science and Research (IJSR)ISSN (Online): 2319-7064Index Copernicus Value (2013): 6.14 Impact Factor (2015): 6.391Design of Five Floors Elevator with SCADASystem Based on S7200 PLCAbdelkarim Ahmed Eltahir Ali1 , Zhang Jiang Min21,2Tianjin University of Technology and Education (TUTE), School of Electronics Engineering Tianjin, China2Professor, Tianjin University of Technology and Education (TUTE), School of Electronics Engineering Tianjin, ChinaAbstract: This paper explains about design of five Floors Elevator with SCADA System Based on S7200 PLC .The elevator mentionedhere is fully automated using PLC. The developed ladder logic has been implemented by Ladder diagram programming the requiredinputs and outputs of the elevator for moving forward and reverse, door opening and closing and motor operation have been included inthe logic and interpreted in addition to that implementation of SCADA system Reduce waste time and improve the efficiency.Keywords: PLC based elevator, Elevator Design, Constant speed Elevator, Ladder logic for Elevator using PLC1. IntroductionElevators are the important medium of verticaltransportation in both residential environment and theindustrial environment. Due to the cause of rapid populationgrowth at the cities and multi-stored buildings, the need ofelevators is being increased. With the rising life standardsand attention to human and with the technologicaldevelopments, elevator systems are getting better, more fast,stronger and better quality elevators are produced.Previously, most systems were focused on the mounting ofelevators, especially after the 1980s the need for elevatormaintenance and fault staff have been started to increase.For instance, automatic doors have being used instead ofsplash doors, microprocessor electronic cards have beingused instead of cards with relay, double-speed or speedcontrolled elevators have being used instead of one-speedelevators. Such developments provide to improve the qualityin elevator systems, develop and diverse the used setting andmaintenance or repair tools and instruments and thereforefacilitation of the work compared to previous years andincrease the reliability of elevator.Some of the drawbacks of the traditional system are thecontrol system have high failure rate that were mainly due tonumerous contacts, complexity of wiring circuit. In addition,electrical contacts were easy to burn out, which could resultin poor contact.Electrical controller and hardware wiring based on commonmethod were difficult to achieve a more complex controlfunction. Electromagnetic actuator and contact action wereso slow, mechanical and electromagnetic have large inertia.Therefore; the control precision of system was difficult.the cabinet is called to any floors the motor either runs inforward or reverse direction and then stop at the floorindicates. The indication of the floor position of the cabinetis given by the limit switches which act as a sensor and givesthe signal indicating that the cabinet has reached therequired position[1].3. Block DiagramFigure1: Elevator block diagramFig.1 shows the overall system block diagram of thisproposed system. The power supply is applied to both motordrive and the plc controller. Motor of the elevator is drivenby the motor drive unit. The elevator cabin in turn driven bythe motor unit. The elevator cabins upside and downsidemovement is controlled the switch operated motor. Theseswitches are controlled by the PLC controller.4. Elevator Control System Components2. Application of PLC for Control System4.1 Stepper MotorThe working principle of PLC for elevator control systemfunctions in the similar manner as that the elevator we use inour daily life. The motion of the elevator that peoplenormally use is controlled by three phases AC motors. Itconsists of a pulley which helps in upward and downwardmovement of the lift. The position feedback is provided bythe limit switches. The principle of this set up is; wheneverStepper Motor is an electromagnetic device that convertsdigital pulses into mechanical shaft rotation. The advantagesof step motors are low cost, high reliability, high torque atlow speeds and a simple, rugged construction that operatesin almost any environment. The disadvantages of a steppermotor is the resonance effect often exhibited at low speedsand decreasing torque with increasing speed. There arePaper ID: NOV162845Volume 5 Issue 4, April 2016www.ijsr.netLicensed Under Creative Commons Attribution CC BY1309

International Journal of Science and Research (IJSR)ISSN (Online): 2319-7064Index Copernicus Value (2013): 6.14 Impact Factor (2015): 6.391basically three types of stepping motors; variable reluctance,permanent magnet and hybrid. They differ in terms ofconstruction based on the use of permanent magnets andiron rotors with laminated steel stators. The motor used forthe development of the set-up is permanent magnet type.The permanent magnet motor, also referred to as a "canstack" motor, as the name implies, a permanent magnet rotor.It is a relatively low speed, low torque device with large stepangles of either 45 or 90 degrees [4].5. Problems to be solved through ladderdiagram4.2 Stepper drives M542M542 is a low cost high performance micro stepping driverbased on most advanced technology in the world today. It issuitable for driving any 2-phase and 4-phase hybrid stepmotors. By using advanced bipolar constant-currentchopping technique, it can output more speed and powerfrom the same motor, compared with traditionaltechnologies such as L/R drivers. Its 3-state current controltechnology allows coil currents to be well controlled, withrelatively small current ripple and therefore less motorheating.[10]4.3 Inductive Proximity SensorInductive proximity switches are used to detect the presenceof the elevator without actually contacting. Their high-speedswitching and small size make them indispensable inautomation applications. Inductive proximity switchesconsist of a coil driven by an oscillator. The oscillatorcreates an electromagnetic field which appears at the activeface of the switch. If a metal target enters this area, theelectromagnetic field is reduced and the switch turns on oroff.4.4 ButtonsHall buttons are on a panel on the outside of the elevatorshafts and are used by potential passengers to call anelevator cab to the floor that the pressed summon button islocated on. Floor request buttons are particular elevatorPaper ID: NOV162845controller will be controlling elevator cabs that are in abuilding with 5 floors. Consequently, each cab has 5 floorsrequest buttons labeled 1 through 5 that passengers can useto direct the elevator cabs to the floor that they would like togo to. There is button on the interior panel of each cab. Apassenger can press this button to open the elevator doors orkeep pressing it to keep them open, but only when theelevator cab is stopped at a floor [3].Ladder diagram is used to realize the many functionalities ofthe elevator control system. Some of the functionalities are,program should be written to make the display on whichindicates the upward or downward movement, the door ofthe elevator should be programmed to open and closeautomatically. When the elevator has no request it remains atits current floor with its door closed floor lamp should glowwithin the lift to indicate the current position. As shown infig.2 The main application of PLC is in the signal controlsystem, all the control signals are realized using the PLC, theinput signals are operational modes, safety control signals,car-calls, hall-calls, floor sensors, leveling sensors, dooropening and close signals.All the functions of the elevator control systems are realizedusing the PLC programs, the functions includes registration,displaying the messages about the floors, monitoring thesafety system, monitoring the door opening and closing,prioritizing the hall call, and car calls. Fig.1 indicates theblock diagram of the signal control system. The inputs aregiven to the PLC unit where the corresponding outputs likefloor lamps, hall call lamps, direction lamps, door open andclose lamps are introduced.As an initial move the ladder logic has to be developed forreceiving the input signal from the call buttons [5]Volume 5 Issue 4, April 2016www.ijsr.netLicensed Under Creative Commons Attribution CC BY1310

International Journal of Science and Research (IJSR)ISSN (Online): 2319-7064Index Copernicus Value (2013): 6.14 Impact Factor (2015): 6.391Figure 2: Elevator flow chartElevator System is the system responsible for coordinatingall aspects of elevator service such as travel, speed, andaccelerating, decelerating, door opening speed and delay,leveling and hall lantern signals. It accepts inputs (buttonsignals and sensors etc.) and produces outputs (elevator carsmoving, doors opening, etc.).Fig.3 shows the elevatorcontrol system and corresponding connection to the PLC.Table 1 show elevator ladder diagram inputs and the same isused with the program to get the corresponding output basedon this input. Once the PLC receives the input signal thecorresponding bit will be latched to activate the desiredoutputs as shows in Table 2.Table 1: Elevator ladder diagram inputsTable 2: Elevator ladder diagram outputsFigure 3: Elevator PLC Connections6. The Aim of an Elevator Control SystemThe main aims of the elevator control system are: To bring the lift car to the correct floor. To minimize travel time. To maximize passenger comfort by providing a smoothride. To accelerate, decelerate and travel within safe speedlimits.Paper ID: NOV162845Volume 5 Issue 4, April 2016www.ijsr.netLicensed Under Creative Commons Attribution CC BY1311

International Journal of Science and Research (IJSR)ISSN (Online): 2319-7064Index Copernicus Value (2013): 6.14 Impact Factor (2015): 6.3917. Hall Call Request8. Up and down control signal identificationThere are two kinds of calls in the elevator they are hall calland car call. When the passenger presses the button in thecontrol panel which is outside the elevator cabin that is thehall call. When the passenger presses the button on thecontrol panel which is inside the elevator car that is the carcall. As shown below fig.4 .This ladder program branchcontrol the User from 1 to 4 floors, when the user press thebutton sends out the down signal to inform the PLC tocontrol the elevator to run to the floor where the passenger atFig.6 shows ladder diagram indicates the up moving ordown of the elevator. The combination of hall call and carcalls are used to decide the elevator movement in upward ordownward direction. If the current position of the elevator isless than the first element of the queue then the elevator willmove in the upward direction.Figure 6: Elevator upward downward identification signal9. Seven Segment Display Logic DesignFigure 4: Hall call signal upward ladderThe car position is displayed using seven segments displaythe interior of each elevator cab has a display that indicatesto its passengers which floor the elevator cab is currently on.This system also has floor number display on every flooroutside of the elevator doors. The controller interacts withthis display by sending a signal that tells it which floornumber to display as shown in Fig.7.The below ladder program branch control the passengerfrom 2 to 5 floors, when the passenger press the button sendsout the up request signal to inform the PLC to take theelevator for the floor where the passenger at .Figure 7:common cathode 7-segment display10. Seven Segment Display Logic EquationFigure 5: Hall call signal downward ladderPaper ID: NOV162845Volume 5 Issue 4, April 2016www.ijsr.netLicensed Under Creative Commons Attribution CC BY1312