1. بسم الله الرحمن الرحيم Khartoum Refinery Company E/I Department Siemens PLC_S7-200 Level (1) Eng: Sami Ahmed 2017 PART1 HARDWARE

2. Software: Micro Win V4.0 PLC Type: Siemens S7-200 Duration: 5 Days Prerequisites:  General technical knowledge  good computer skills in the field of Windows Operating Systems. Maximum Delegates: 6 Siemens PLC_S7-200 Level (1)

3. Schedule: 8.00 - 9.00 9.00 - 9.20 Break 9.20 -10.20 10.20-10.40 Break 10.40-11.40 Schedule

4.  Be able to recognize S7 200 hardware and be able to replace modules when a fault occurs.  Be able to operate the Step 7 200 software to make it perform certain tasks.  Understand basic S7 200 instruction set and be able to make minor modifications to software.  Be able to backup and restore a PLC program when required.  Be able to perform basic system diagnostics when a problem occurs. Objectives

5.  Introduction  Components PLCs  Input /Output Module structure  Numbering System  Terminology  Programming  The advantages of using a PLC  Different PLC models made by Siemens  S7 families of PLCs Contents (hardware)

6. Introduction What is meant by PLC?  PLC is an abbreviation for “Programmable Logic Control”.  It is simply a special computer device used for industrial control systems, figure (1). figure (1)

7. Components of PLC  PLC like any PC, consists of, figure (2): 1.Central Processing Unit. 2.Input/Output (I/O) interface system. figure (2)

8. Components of PLC The following three components form the CPU, figure(3): 1-Processor Unit (CPU) 2-Memory Unit 3-Power Supply figure(3)

9. The basic elements of a PLC include input modules or points, a central processing unit (CPU), output modules or points, and a programming device. Input Module: The type of input modules or points used by a PLC depends upon the types of input devices used. Some input modules or points respond to digital inputs, also called discrete inputs, which are either on or off. Other modules or inputs respond to analog signals, figure(4) & figure(5). Components of PLC

10. Figure(4) Displays how to generate a signal by a pushbutton switch. Figure(5) displays a limit switch and thermostat as Input devices

11. CPU: The CPU evaluates the status of inputs, outputs, and other variables as it executes a stored program. The CPU then sends signals to update the status of outputs. Output Module: Output modules convert control signals from the CPU into digital or analog values that can be used to control various output devices. Components of PLC

12. Relays and Contactors are the most important output devices. Relay : is used to switch a large amount of electrical power through its contacts, figure(6). Contactor. Contactors typically have multiple contacts, and those contacts are usually (but not always) normally-open, so that power to the load is shut off when the coil is de-energized, figure(7).  A contactor is used for a higher load.

13. figure(6) displays a Relay in 3-phase motor circuit figure(7) Displays at the top, a contactor and a motor. At the bottom it shows the, deactivated/activated contactor symbol and their connections to a PLC.

14. A solenoid valve is an electromechanical valve for use with liquids or gas, figure(8). figure(8)

15. Components of PLC  programming device is used to enter or change the PLC’s program or to monitor or change stored values. Once entered, the program and associated variables are stored in the CPU, figure(9).  operator interface device (Human Machine Interface) to simplify monitoring of the machine or process. figure(9)

16.  In the simple example shown below, pushbuttons (sensors) connected to PLC inputs are used to start and stop a motor connected to a PLC output through a motor starter (actuator). No programming device or operator interface are shown in this simple example, figure(10). Components of PLC figure(10)

17.  LOGO!  SIMATIC S7-1200.  SIMATIC S7-200.  SIMATIC S7-300.  SIMATIC S7-400. Siemens SIMATIC PLCs figure(11)

18. Input Module structure:  Usually input signals are 24 v ac or dc. These signals go through a current limiter resistor, a LED, then finally connects to input of Opt coupler, See figure12. Input /Output Module structure Figure 12

19. Input /Output Module structure It is much better to isolate all a PLC’s communication with the outside world. Output modules structure: Output modules transfer signals from a PLC’s microprocessor to outside world devices. Usually signals are digital (5V DC) and need to be change to higher voltages such as 24V or 230V AC or DC. Again, regarding the structure of output modules, opt coupler circuits are used to create electrical isolation between PLC and output field devices such as contactors, lamps, etc, See figure 1-13.

20. Output modules are categorized as either Analog or Digital types, Digital modules are categorized into 3 main types, figure13. Input /Output Module structure Relay output moduleTriac output moduleTransistor output module Figure 13

21. Why do we put a diode across a relay's coil? To protect the transistor from damage due to the back-e.m.f. generated in the relay coil's inductance when the transistor turns off." When you apply a voltage to a coil is creates a magnetic field. When you remove the voltage the magnetic field collapses and creates a reverse polarity voltage, This creates a transient voltage pulse that can damage transistor. Input /Output Module structure

22. The R-C Snubber: is intended to suppress the “inductive kick back” from motors, solenoids, relay coils, pumps or any device that creates an electro-magnetic collapsing field. High energy noise spikes are generated whenever current is interrupted through an inductive load connected to a switching circuit. These electro-magnetic noise spikes (EMI) may interfere with electronics equipment causing erratic operation, CPU failure and may also accelerate relay contact wear. Input /Output Module structure

23. Applied across an inductive load, the R-C snubber suppresses the electrical noise spikes to electronics and extends contact life on mechanical relays.

24. Since a PLC is a computer, it stores information in the form of On or Off conditions (1 or 0), referred to as binary digits (bits).Sometimes binary digits are used individually and sometimes they are used to represent numerical values. Decimal system: Various number systems are used by PLCs. All number systems have the same three characteristics: digits, base, weight. The decimal system, which is commonly used in everyday life, has the following characteristics: Ten digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Base 10 Weights 1, 10, 100, 1000,... Number Systems

25. Binary system: The binary system is used by programmable controllers. The binary system has the following characteristics: Two digits 0, 1 Base 2 Weights Powers of base 2 (1, 2, 4, 8, 16,...) Converting binary to decimal: Number Systems

26. Bits, bytes, and words: Each binary piece of data is a bit. Eight bits make up one byte. Two bytes, or 16 bits, make up one word. Number Systems

27. Logic 0, logic 1: The binary system is a system in which there are only two numbers, 1 and 0. Binary 1 indicates that a signal is present, or the switch is On. Binary 0 indicates that the signal is not present, or the switch is Off, figure14. Number Systems Figure 14

28. BCD: Binary-Coded Decimal (BCD) are decimal numbers where each digit is represented by a four-bit binary number, figure15. Number Systems

29. Hexadecimal: Hexadecimal is another system used in PLCs. The hexadecimal system has the following characteristics: 16 digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F Base 16 Weights Powers of base 16 (1, 16, 256, 4096...) A = 10 D = 13 B = 11 E = 14 C = 12 F = 15 To convert decimal 28, for example, to hexadecimal: Decimal 28 divided by 16 is 1 with a remainder of 12. Twelve is equivalent to C in hexadecimal. The hexadecimal equivalent of decimal 28 is 1C. Number Systems

30. Twelve is equivalent to C in hexadecimal. The hexadecimal equivalent of decimal 28 is 1C. the hexadecimal number 2B is converted to its decimal equivalent of 43. Number Systems

32. The language of PLCs consists of a commonly used set of terms; many of which are unique to PLCs. Sensor: is a device that converts a physical condition into an electrical signal for use by the PLC. Sensors are connected to the input of a PLC. A pushbutton is one example of a sensor that is connected to the PLC input. An electrical signal is sent from the pushbutton to the PLC indicating the condition (open/closed) of the pushbutton contacts, figure15. Terminology Figure15

33. Actuators: convert an electrical signal from the PLC into a physical condition. Actuators are connected to the PLC output. A motor starter is one example of an actuator that is connected to the PLC output. Depending on the output PLC signal the motor starter will either start or stop the motor, figure16. Terminology figure16

34. Discrete input: also referred to as a digital input, is an input that is either in an ON or OFF condition. Pushbuttons, toggle switches, limit switches, and contact, figure17. Terminology figure17.

35. Analog inputs: is an input signal that has a continuous signal. Typical analog inputs may vary from 0 to 20 milliamps, 4 to 20 milliamps, or 0 to 10 volts. In the following example, a level transmitter monitors the level of liquid in a tank, figure 18. Terminology Figure 18

36. Discrete outputs: an output that is either in an ON or OFF condition. Solenoids, contactor coils, and lamps are examples of actuator devices connected to discrete outputs. Discrete outputs may also be referred to as digital outputs, figure19. Terminology figure19

37. Analog outputs: is an output signal that has a continuous signal. The output may be as simple as a 0-10 VDC level that drives an analog meter. Examples of analog meter outputs are speed, weight, and temperature. The output signal may also be used on more complex applications such as a current-to pneumatic transducer that controls an air- operated flow-control valve, figure20. Terminology figure20

38. central processor unit (CPU): is a microprocessor system that contains the system memory and is the PLC decision making unit. The CPU monitors the inputs and makes decisions based on instructions held in the program memory. The CPU performs relay, counting, timing, data comparison, and sequential operations, figure21. Terminology figure21

39. Programming: consists of one or more instructions that accomplish a task. There are several ways to look at a program such as ladder logic (LAD), statement lists (ST), or function block diagrams (FBD). Ladder logic: Ladder diagrams are specialized schematics commonly used to document industrial control logic systems. They are called ladder diagrams because they resemble a ladder with two vertical rails (supply power), and as many as rungs (horizontal lines) as there are control circuits to represent. Programming

40. The figure22 displays a simple ladder diagram without power supply shown The figure23 added power supply wiring to the ladder diagram Programming figure22 figure23

41. Ladder diagrams are used to describe the logic of electrical control systems. There are differences in the way ladder logic is implemented in computerized form compared to hard-wired. The basic component of the control system is the control relay, which is a solenoid that operates a number of switches or contacts. The contacts come normally-open and normally-closed, normal being when the relay is not energized. Programming

42. the field devices, such as push buttons, limits switches, lights, and controlled devices such as motor starters and solenoid operated valves. figure24 displays standard motor control circuit (Start /Stop Circuit) Programming

43. Figure25 displays 3 phase motor circuit with the controlling circuit on the right side of the figure Programming

44. Ladder Logic: Ladder logic is the main programming method used in PLCs. Relay: is a simple device that uses a magnetic field to control a switch, as pictured in Figure26. Programming Figure26

45. In this system figure27 the first relay on the left is used as normally-closed, and allows current to flow until a voltage is applied to the input A. The second relay is normally-open and will not allow current to flow until a voltage is applied to input B. If current is flowing through the first two relays, then current will flow through the coil in the third relay, and close the switch for output C. Programming

46. figure27

47. The ladder logic in the PLC is actually a computer program that the user can enter and modify it any time he needs. Input / output filed devices used in ladder diagrams, figure28: Programming figure28

48. the symbols of input field devices used in “Relay Logic” circuit diagrams figure29: figure29 Programming

49. Figure 30 shows an example “Relay Logic circuit diagram” of a seal in circuit. In this circuit switch PB1 activates relay RL1. After the activation, since it is a seal in circuit, it stays activated and the “RED” light turns ON. It stays ON until PB2 is depressed. In that case, the “GREEN” light turns ON. Figure 30 Programming

50. Figure31displays ladder diagram of seal in circuit Up/down lifter system A Pictorial diagram of lifter system is given in figure. We wish to design a ladder diagram of a controller circuit with respect to the given conditions: 1- The system turns ON and is ready to function as soon as PB1 is depressed Programming

51. 2- Depressing PB2 shuts down the system 3- PB3 & PB4 used to get the system move UP or DOWN accordingly. Figure 32displays an up or down lifter system Programming

52. Step 1- defining field Input devices: 1- Switch PB1 to START the system 2- Switch PB2 to STOP the system 3- Switch PB3 to move system UP 4- Switch PB4 to move system DOWN 5- Limit switch LS1 for up motion limit 6- Limit switch LS2 for down motion limit Defining field output devices: 1- M1 motor to move system UP 2- M2 motor to move system DOWN Programming

53. Defining how the lifter should function: Any time PB1 or START push button is depressed, the lifter must be placed in moving down motion status. Depressing PB2 or STOP keeps the lifter in the same steady state. Depressing PB3 or UP, moves lifter up as much as LS1 limit switch and when PB4 is depressed, it moves lifter down as much as LS2 limit switch. When M1 is turned ON, M2 must be OFF for sure, and vice versa. Programming

54. The Figure 33 displays complete ladder diagram of a lifter system which consists of seven rungs. Rung 1 is related to the “preparation phase”, when it is activated then Rung 2 and Rung 4 can be activated, hence M2 & CR3 = ON. In Rung 4 if CR1 = ON & CR2 = OFF, then CR3 can turn ON which is considered as Circuit’s Master Relay. Rung 2 feeds M2 which controls the “down movement” direction. Rung 2 is activated by either CR1 or CR5. Rung 3 controls STOP function. Rung 5 is related to UP movement function. As you see in Rung 6, if CR4 = ON but CR5 = OFF then M1 = ON and UP movement can occur. The lifter can continue UP movement as long as LS1 = OFF. And finally, Rung7 controls down movement operation. When PB4 is energized, (If CR3 = ON and LS2 = OFF), CR5 stays ON and Down movement operation can occur. Programming

55. Figure33 displays complete ladder diagram of the lifter system

56. Programming By using extra contacts of Relays M1 and M2, the ladder diagram shown in Figure 33 can be further simplified. Figure 34 is the final version of circuit diagram designed for the lifter system. Figure 34 simplified version of figure 33

57. Programming Programming with a typical PLC Figure 35 illustrates a simplified hardware view of a typical PLC that has 3 input and 3 output terminals. Figure 35 a simplified view of a PLC

58. Programming The actual logic of the control system is established inside the PLC by means of a computer program. The program is edited and viewed via a PC connected to the PLC’s programming RS232 or USB Port. Software usually is downloaded to the PLC and is run after the execution command is issued. Figure 36 shows the de-activated input port channel I0.1 and the lamp is off

59. Programming Look over the circuit and PLC program below figure 37. figure 37

60. Programming In figure 38, you see the altered software shown where the pushbutton is its un actuated state. figure 38

61. Programming Figure 39 displays the equivalent circuit with three pushbutton switches Figure 39

62. Programming Figure 40 displays the wiring and ladder diagram of a motor start circuit. Figure 40

63. Programming Figure 41 the conductor stays energized

64. Programming Figure42displays start \stop motor circuit in which the Motor Stop switch is actuated

65. 1- Controlling circuitry is smaller 2- Ease of troubleshooting 3- Less need to repair 4- A PLC can execute much complicated functions in the controlling systems 5- A PLC can easily establish communication with other process control systems The advantages of using a PLC as a controller are:

66. Different PLC models made by Siemens Siemens categorizes its range of PLCs under the name SIMATIC, Figure43. SIMATIC S5 These PLCs are older versions of SIMATIC models:  S5-90U or S5-95U for a limited range of application and functionality.  S5-100U or S5-115U for middle range of application.  S5-155U and 135U For a broader range of application. figure43 illustrates some models of SIMATIC S5 PLCs

67. Different PLC models made by Siemens SIMATIC S7 PLCs (Figure 44) : SIMATIC S7 PLCs are the next generation of controllers built after the S5 series. The S7 series come in three different models which are the:  S7-200 (compact): is used to control relatively small systems  S7-300 (modular): for mid-range applications.  S7-400 (modular): can be used over a broader range of control systems. Figure 44 illustrates several different models of S7 PLCs

68. Different PLC models made by Siemens LOGO (Logic Modules): Figure 45 is an inexpensive and simple controller which is used for small control projects (inside of buildings or simple machinery). LOGO is a compact PLC which is programmed by the keyboard on its panel or one can use LOGO! Soft Comfort software to program via a PC and then download the software program into the LOGO’s memory. Figure 45 illustrates a LOGO! Compact PLC

69. Different PLC models made by Siemens SIMATIC C7 The C7 is a combination of S7-300 and Operator Control. It can be used to do control tasks and at the same time, it can accept data via its keyboard and check different messages, results of measurements, and check control processes on its LCD display, figure46. Figure 46 illustrates A SIMATIC C7 626 programmable controller

70. Different PLC models made by Siemens SIMATIC 505 The SIMATIC 505 series is designed and built as a compact PLC for small and medium process control applications. TISOFT software is used to program it. Both its hardware and software is designed by Texas Instruments. Figure 47 illustrates a SIMATIC 505 PLC

71. S7 families of PLCs S7-200 :  It is an inexpensive PLC  It can be used for relatively simple to complicated tasks  Its installation and programming is simple  It is a compact PLC with inputs/outputs on-Board  It has different models, some models are built modular  STEP 7- Micro/Win is used to program Figure 48 illustrates a S7-200 PLC

72. S7 families of PLCs S7-300  It is a mini PLC  It has medium range of application  It is a modular PLC  It comes in a verity of models  It is easily expandable  STEP 7 (SIMATIC MANAGER) software is used to program it Figure 49 illustrates a SIMATIC S7-300 PLC

73. S7 families of PLCs S7-200 PLCs are built with two different generations of CPUs. Figure 50 displays different categorized models of S7-200 PLCs based on their CPUs. Figures 51 illustrate few different models of CPU 21X and 22X PLCs. Figure 50

74. S7 families of PLCs Figure 51 illustrates 4 typical models of 22 X series – from top left CPU 221, CPU 222, CPU 224 and finally CPU 226

75. S7 families of PLCs Figures 52a and 53 displays how two different models of the SIMATIC S7/200 family can be hardwired to input/output devices. As an example, CPU 221 DC/DC/DC is supposed to be energized by a 20.4 to 28.8 VDC power supply, it has 14 DC inputs and 10 DC outputs (Figures 52a ). On the other hand, CPU 222 AC/DC/RLY (is supposed to be powered by 85-264 VAC mains power source @ 47-63 Hz), has 8 DC inputs and 6 relay outputs, figure 53.

76. S7 families of PLCs Figure 52(a) displays how the S7-200 model 6ES& 214-1AC01 is hardwired to I/O field devices.

77. S7 families of PLCs Figure 52(b) displays I/O, power supply and DC sensor supply section of the S7-200 model pictured in figure 52(a)

78. S7 families of PLCs Figure 53

79. S7 families of PLCs In figure 52 (a) there are a number of LEDs which inform the operator what is the working condition of PLC in use. The meaning of any led is turned on/off is as following: Status LEDs: SF: System Fault RUN: the PLC is executing a program STOP: stand by mode. I/O LEDs: turns on anytime, each input or output port is activated SELECTOR SWITCHES: RUN: the CPU executes the prepared software. STOP: The CPU STOPS execution when switch on stop position. TERM:PLC operator is ready to choose the PLC’s operating mode.

80. S7 families of PLCs POT1, POT2: analog potentiometers to control analog sensor settings (top right). M/L :(output DC Sensor Supply) terminals: PLC provides 24 VDC power for input sensors or expansion modules (280 mA). RS232 Port:: is used to connect PLC to a PC and download programs.

81. S7 families of PLCs Figure 54displays different configuration of SIMATIC S7-200 PLCs