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  • 1. I.LI354 Programmable Logic Controller . . 1

2. , . Add. , , Tel: +976-96638295 E-mail: 2magnai@must.edu.mn, magnai320@yahoo.com 3. : 1. 2. 3. PLC 4. PLC 5. PLC 6. PLC 7. PLC 8. Advantages and Disadvantages 9. PLC PLCs Applications 10. PLC PLC hardwares 11. 3 4. 4 5. Process Control & Automation5 6. PLC CONTROL ELECTRONIC CONTROL HARD WIRED CONTROL MANUAL CONTROL 6 7. MANUAL CONTROL . 7 8. HARD WIRED 8 . . PLC 9. ELECTRONICS CONTROL . : 9 10. PROGRAMMABLE LOGIC CONTROLLER PLC .10 11. PLC- Programmable logic controller (PLC) . PLC- . 11 12. : 1960- PLC 1970 . PLC (General motors) . 1980- . 12 13. Devices Relays Contactors Motor Starters Manually operated switches Mechanically operatedswitches Electrically operated switches13 14. Relays Original controlelements .Now used as auxiliary devices The PLC is not designed to switch high currents or voltagesCR1-1 CR114 15. Manually Operated Switches Pushbuttons Normally open Normally closedSelector switches Maintained or spring return15 16. Mechanically Operated Switches Limit Switches Temperature Switches Pressure Switches Level Switches16 17. Electrically Operated Switches Photoelectric Switches Proximity Switches17 18. PLC- Characteristics of PLC (1) , Versatility, flexibility and simple wiring (2) Strong function and expanpsion (3) High reliability and strong antiinterference (4) Programming and wiring can synchronously18 19. PLC- Characteristics of PLC (1) , PLC . PLC "soft wiring" 19 20. PLC- Characteristics of PLC (2) Strong function and expanpsion - - 20 21. PLC- Characteristics of PLC (3) High reliability and strong anti-interference Hardware: , , , . Software: , 21 22. PLC- PLCClosed-loop 22Network 23. (1) . . : , , , 23 24. (2) : , , . RTD , . PLC . 24 25. (3) Closed-loop PLC . PID .25 26. (4) , PLC 26 27. Network (5) Network Communications PLC , .27 28. 28 29. 29 30. PLC- 30 31. PLC- (1) I/O points (2) By construction31 32. PLC- By I/O points (1) : Micro: 32 I/O Small: 256 I/O Medium: 1024 I/O Large: 4096 I/O32 33. PLC- (2) By construction Compact PLCs Modular PLCs33 34. PLC- (1) CompactMonolithic construction Monoprocessor Fieldbus connection Fixed casing No process computer capabilities (no MMC) Fixed number of I/O (most of them binary)(2) Modular PLC Modular construction (backplane) One- or multiprocessor system Fieldbus and LAN connection DIN-rail Large variety of input/output boards Connection to serial bus34 35. Compact modular ? field bus extension compact PLC (fixed number of I/Os) modular PLC (variable number of I/OsLimit of local I/O# I/O modules 35 36. Programming languages PLC (1) Ladder logic (2) Statement list (3) Function blockdiagram36 37. PLC Ladder diagramladder diagram The instructions are represented :by graphic symbols Contacts, Coils & Boxes Statement list37Function block 38. PLC Siemens PLC 38 39. : Flexibility: Correcting Errors: Space efficient: Low cost: Testing: Visual observation: Number of contacts many: Resistant character test : Simplifies the control system components Security : Documentation: Can make changes by reprogramming in seconds.39 40. PLC- 40 41. PLC:Location in the control architecture Engineer stationOperator stationSupervisor StationEnterprise Network gatewaydirect I/OField Stationsdata concentrators, not programmable, but configurable41CPU I/O COM 2Sensor Bus (e.g. ASI)gatewayCOMFB gatewaysmall PLCPLCField Bus COM CPUCOM I/O I/O I/OCOM CPUField Bus COM CPU I/O I/O I/O I/Odirectly connected I/OControl Station with Field BusCOM1PLCCPU COM1 COM 2 I/O I/O I/O I/Olarge PLCsCPU COM1 I/O I/O I/O I/O I/OControl Bus (e.g. Ethernet)Field Devices 42. PLC- :42 43. PLC- PowerCPU Input DevicesInput moduleArithmetic unitOutput moduleControl unit Peripheral I/O Interfaces 43MEMORY EPROM RAM Extension I/O InterfacesOutput Devices 44. 44 45. 45 46. CPU: Power supply unit: A.C. D.C. .46 47. Input-output sections: .47 48. Expansion Modules: The S7-200 PLCs are expandable. . /ribbon connector/ .48 49. Memory unit: .49 Programming device: . 50. PLCs invented to Replace Relays and HARD WIRING: Prior to PLCs, many of these control tasks were solved with contactor or relay controls.50 51. PLC : Siemens, Allen Bradley, Omron, Schneider, 51 52. 52 53. S7-200 configuration53 54. S7 200 family54 55. S7-200 configuration inputs55 56. S7-200 configuration outputs56 57. S7-200 configuration I/O numbering57 58. Analogue I/O Typical analogue signals from 0-10 VDC or 4-20 mA= They are used to represent changing values such as temperature, weight and level58speed,= 59. Instructions :Standard instructions .They are used in most programs Examples: timer, counter, math, logical, incr., decr. and move :Special instructions They are used to manipulate data .Shift, table, conversion, real time instruction:High speed instructions They allow for events and interrupts to occur independently of .the PLC scan time Examples: High speed counters and interrupts 59 60. Input InstructionsBit Logic instruction Normally Open contact Normally Closed contact Normally Open Immediate contact Normally Closed Immediate contact Positive Transition contact Negative Transition contact Not contact 60 61. Input contacts example61 62. Output instructions Output Instruction Output Immediate instruction No Operation instruction Set (N bits) instruction Reset (N bits) instruction Set Immediate (N bits) instruction Reset Immediate (N bits) instruction 62 63. Output, Set & Reset example63 64. Starting a motor64 65. Hard-wired DOL(direct-on-line ) startingO.L. contact Circuit Breaker Contactor Thermal OverloadStar tStop Aux. contactContact coilInduction Motor 65Induction Motor 66. Using PLC Before startStartingAfter start66 67. Stopping67 68. Input & Output connections68 69. Timer instructions On-Delay TimerRetentive On-Delay TimerOff-Delay Timer69 70. On-Delay & Retentive On-Delay timersThey count time when the enabling input (IN) is ON. When the current value (Txxx) is > the preset .time (PT), the timer bit is ON The On-Delay timer current value is cleared when (IN) is OFF, while the current value of the Retentive .On-Delay Timer is maintained You can use the Retentive On-Delay Timer to .accumulate time for multiple periods of the input ON 70 71. Off-Delay timerThe Off-Delay Timer is used to delay turning an output OFF for a .fixed period of time after the input turns OFF When (IN) turns ON, the timer bit turns ON immediately, and the . current value is set to 0 When (IN) turns OFF, the timer counts till PT and the timer bit .turns OFF and the current value stops counting If the input is OFF for a time shorter than PT, the timer bit .remains ON 71 72. Timers numbers & resolutions72 73. Timer examples On-DelayRetentive On-DelayOff-Delay73 74. Hard-wired on-delay timer74 75. le75 76. TONR example76 77. Timer example77 78. Memory types You can access data in many CPU memory areas- process image input register - process image output register - variable memory area - Bit memory area - sequence control relay memory area - special memory bits - local memory area - Timer memory area - counter memory area - Analog inputs 78(I) (Q) (V) (M) (S) (SM) (L) (T) (C) (AI) 79. Memory addressing )Accessing a Bit of Data in the CPU Memory (Byte.bit Addressing79 80. Memory addressing You can access data in many CPU memory areas (V, I, Q, M, S, L, :and SM) as .bytes, words, or double words by using the byte-address format80 81. Memory types Process-image input register (I) : Format Bit I[byte address].[bit address] I0.1 Byte, Word, Double Word I[size][starting byte address] IB4 Process-image output register (Q):Format Bit Byte, Word, Double Word Q[byte address].[bit address] Q1.1 Q[size][starting byte address] QB5Variable memory area (V) :You can use V memory to . store intermediate results of the control logic operations . store other data pertaining to your process or task :FormatBit Byte, Word, Double Word 81V[byte address].[bit address] V10.2 V[size][starting byte address] VW100 82. Memory types Sequence control relay area (S) They are used to organize machine operations or steps into equivalent program segments. SCRs allow logical segmentation of the control :Format Bit S[byte address].[bit address] S3.1 Byte, Word, Double Word S[size][starting byte address] SB4 Special memory bits (SM) The SM bits provide a means for communicating information between the CPU and your program. You can use these bits to select and control some :of the special functions of the S7-200 CPU, such as A bit that turns on for the first scan cycle Bits that toggle at fixed rates Bits that show the status of math or operational instructions :Format Bit SM[byte address].[bit address] SM0.1 Byte, Word, Double Word SM[size][starting byte address] SMB86 82 83. Memory types Local memory area (L) The S7-200 PLCs provide 64 bytes of local (L) memory of which 60 can be used as scratchpad memory or for passing formal parameters to subroutines. Format: Bit L [byte address].[bit address] L0.0 Byte, Word, Double Word L [size] [starting byte address] LB3383 84. Memory types Analog inputs (AI) The S7-200 converts a real-world, analog value (such as temperature or voltage) into a word-length (16-bit) digital va