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What's PLC?

What's PLC ?

PLC ? 

      PLC Ҩҡ Programmable Logic Controller ػóǺ礷͹ԡ ˹ 㹡 Program ѺǺ÷ӧҹͧػóҧ ͧǺԧáö ¡¡ ᵡҧѹ͡仴ѧ

- PC Programmable Controller յ鹡ԴҨҡҪͳҨѡ 㹻Ѩغѹ PLC ҧ ¡ PLC ͧͧ PC µѴ Logic ͡ PLC ͧҷҡ Logic (ON-OFF) ͧҡ PC Ѻ仵çѺ Personal Computer µͧ¡ PLC ѹ
- PLC Programmable Logic Controller յ鹡ԴҨҡѰԡ
- PBS Programmable Binary System յ鹡ԴҨҡഹ

     PLC ͧǺѵѵԷö PLC ١ҧоѲ᷹ǧѹͧҨҡͧ÷ҡͧǺҤҶ١ öҹҧ๡ʧö¹ҹ

ᵡҧҧ PLC Ѻ COMPUTER
1. PLC ١͡Ẻ ҧ鷹ҾǴçҹصˡ੾
2. Сҹ PLC ҡ͹ PLC кǨͺͧ
    ǧõԴ駨֧ǧҹ úاѡҷ
3. PLC ١ѲդöõѴԹ٧ ҹдǡ зԸҡЫѺ͹

ѵ PLC ʹյ֧Ѩغѹ 

.. 1969
- PLC ١ѲҢҤá ѷ Bedford Associates Modular Digital Controller (Modicon)
        Ѻ.çҹԵö¹ԡҪ General Motors Hydramatic Division
- ѷ Allen-Bradley ʹкǺ PLC

.. 1970-1979
- աþѲ PLC աûżŷҡ鹵¹ŧͧ Micro-processor
- ö㹡õԴҧ PLC Ѻ PLC кá Modbus ͧ Modicon
- աԹط/ҷطѭҳ Analog

.. 1980-1989
- դҧҵðҹ㹡âŢͧ PLC ºѷ  General Motors ҧⵤŷ¡ manufacturing automatic protocal (MAP)
- Ҵͧ PLC Ŵŧ
- ԵͿö PLC symbolic öҹҧ personal computer ᷹ҹҧ handheld programing terminal

.. 1990-Ѩغѹ
 - դ㹡÷зҷ㹡 PLC ҵðҹǡѹҵðҹ  IEC1131-3
 - ö PLC
 - IL (Instruction List)
 - LD (Ladder Diagrams)
 - FBD (Function Block Diagrams)
 - SFC (Sequential Function Chart)
 - ST (Structured Text)
 

 

ѡɳçҧ㹢ͧ PLC 觻Сͺ

  

1.ǻż(CPU)
          ˹ҷӹdzФǺ º͹ͧͧ PLC
㹻СͺǧͨԡªԴ (Micro Processor Based)᷹ػóӾǡ ҹ/ Ыǹ ö͡Ẻǧ Relay Ladder Diagram CPU ѺŨҡػóԹطҧ ҡ鹨зӡûż红ҡ˹¤ ѧҡ鹨觢ŷж١ͧ͡ѧػóҷط

2.˹¤(Memory Unit)
          ˹ҷѡТŷ㹡÷ӧҹ ¢Ҵͧ˹¤Өж١͡繺Ե(Data Bit) ˹¤ 1 Ե դзҧͨԡ 0 1ᵡҧѹ
˹¤кͨԡ͹ ͡ 2

          Volatile Memory ˹¤ӪԴ ٭ աè¡ѧҹ俿Ѻ˹
˹¤ẺЧ㹡¹ŧ ź ˹¤ӻ RAM 繵

          Non-Volatile Memory ˹¤ӷö红 颳з è¡ѧҹ俿
Ѻ˹¤ ˹¤Ẻ ҡ㹡¹ŧ ˹¤
˹¤ӻ ROM , EPROM EEPROM 繵

 

Ҿʴçҧ㹡èѴ˹¤к ͨԡ͹

          RAM ˹ҷͧТŷ㹡ûԺѵԧҹͧ PLC ˹¤ӻẵ §Դ俴Ѻ ҹС¹ŧ RAM ҡ  Щй鹨ҡѺҹзͧͧա¹ŧ
          ROM ˹ҷѺ㹡ûԺѵԧҹͧ PLC ͧ ˹¤Ẻ ROM ѧö EPROM 觨еͧػó㹡¹ź СѺҹͧ¹ŧ ͡ҡѧẺ EEPROM ˹¤ӻͧͧ;㹡¹ź öҹ͹Ѻ RAM ͧẵͧ ҤҨᾧͧҡسѵԢͧ ROM RAM ¡ѹ

           çҧèѴ˹¤ к ͨԡ͹
èѴ˹¤ к ͨԡ͹ ͡ 3 ǹ
˭

          2.1 System Memory ˹¤ǹ˹¤ӷ˹ҷ㹡ä÷ӧҹ к
ͨԡ͹ ͡ 2 ǹ
                    • Executive Memory ˹¤ӻ ROM , EPROM 觨˹ҷ èѴ
           кͧ ͨԡ͹, Ңͧ˹ҷ
           öзӡûż , Ǻ᡹ 繵
                    • Scratch Pad Memory ˹¤ӪǤ 红 㹢зӡûżǹͧ
           Executive Memory ˹¤ӻ RAM öҶ֧˹¤ ǹ

           2.2 Input / Output Status Memory ˹¤ ˹ҷ 㹡ʶҹ ͧѭҳ
Թط ҷط ʶҹТͧԹط ҷط 㹡ûż 1 ͺ᡹ դ
ʶҹеҧ椧 ʹûż ˹¤ǹ RAM ǹͧ
ͨԡ͹ SIMATIC S7 ¡˹¤ǹ PII ( Process Image Input ) ˹ҷ
ʶҹТͧѭҳԹط PIQ ( Process Image Output ) ˹ҷ 㹡ʶҹТͧѭҳҷ
ط

            2.3 Application Program ˹¤ǹ ШѴѺ㹡红ŵҧ 㹡û
ż (Data Memory) ˹¤ӷ 㹡äǺ ˹»żšҧ
㹡ûż


          
 
3.˹Թص-ҵص (Input-Output Unit)
          ˹Թص ˹ҷѺѭҳҡػó¹͡ŧѭҳѭҳ˹»żŵ

          

            3.1 ˹ͨԡԹط ( Logic Input Unit )˹ԹطẺ ѡɳТͧ Թ Ẻ Discrete Interfaces з˹ҷҧ˹»żšҧ Ѻ ػóԹط¹͡ ѡɳѭҳ亹 ԨԵ ҹǹѭҳҹһѺдѺѭҳѺ÷ӧҹͧ ˹»żšҧ ͷӡûżŵ觷ҧ çҧ㹢ͧ˹ͨԡԹطẺ ͡ 2 Դ Ẻ DC ͨԡ Ẻ AC ͨԡ ʴѧҾ

 


Ҿʴçҧ㹢ͧ ˹ͨԡԹط Ẻ DC 

          ǧ㹢ͧ ͨԡ͹ дѺçѹ㹡ûԺѵԡ 5 Vdc ػó
¹͡ çѹ㹡ûԺѵԡ٧ 24 Vdc ֧ 48 Vdc 110 Vac ֧ 220 Vac дѺͧ
çѹ Ѻػó¹͡ ҨзԴ¡Ѻػó礷͹Ԥ к
ͨԡ͹ ͧҡçѹ˹ǹӷԴѭҳ кǴͧ
ͨԡ͹ ͧѡ кǹüԵ ᵡҧѹ


Ҿʴçҧ㹢ͧ ˹ͨԡԹط Ẻ AC

            3.2 ˹͹͡ Թط( Analog Input Unit )Ѻѭҳѡɳеͧ ѭҳ͹͡ ͨԡ͹ ͧѺѭҳԹط͹͡㹷ҧԺѵҨйѭҳ͹͡ҹҼҹŧѭҳԨԵ (Analog to Digital Converter) ͷ¡ ADC ͹ Ǩ֧ѭҳ㹡ûż͵ͧѭҳҷط͹͡ йѭҳԨԵŷҡûżҼҹŧѭҳ͹͡ (Digital to Analog Converter) ͷ¡ DAC ͹ Ǩ֧ѭҳ㹡äǺػóҷط¹͡

            ˹ԹطẺ͹͡ ͧͨԡ͹ Ѻѭҳ͹͡ ҧ ҡ
¹͡ ·ѭҳҹ鹨ж١¹ٻͧѭҳҧ俿
           • çѹ 觹ѹ㹪ǧ 0-10 ŵ , 1-5 ŵ, 0-5 ŵ 繵
           • 觹ѹ㹪ǧ 0-20 , 4-20 繵

            ѧ鹡͡˹ԹطẺ͹͡ е֧ͧԨóҶ֧ѡɳТͧѭҳԹطҡૹ
ҹԵ Ẻ çѹ 觨çҧ㹢ͧ˹Թط ᵡҧѹʴѧ
Ҿ

 

Ҿʴçҧ㹢ͧ ˹͹͡Թط ٻͧçѹ

  


Ҿʴçҧ㹢ͧ ˹͹͡Թط ٻͧ

 

      ˹ҵص ˹ҷѺŨҡǻż觵͢令Ǻػó¹͡ Ǻʹ 繵

 

             3.3 ˹ͨԡҷط( Logic Output Unit )ѭҳѡɳ亹 ԨԵ ͡令Ǻػóӧҹ¹͡ 觨ǹСͺӤѭ ػó§ҧʧ ¡ѭҳ ҡǧ㹢ͧͨԡ͹͡ҡ ǹͧػóǺ¹͡ ͻͧѹ¢ͧǧ㹷Դ ͧҡǹͧػó¹͡


Ҿ ʴçҧ㹢ͧ ˹ͨԡҷطẺ DC

 
Ҿ ʴçҧ㹢ͧ ˹ͨԡҷطẺ AC

            3.4 ˹͹͡ҷط ( Analog Output Unit )ѭҳѡɳеͧ ѭҳ ͹͡͡令ػóӧҹ¹͡˹͹͡ҷطᵡҧѹ Ѻ ѡɳТͧѭҳ͹͡ٻͧçѹ çҧ ʴ ѧҾ


Ҿʴçҧ㹢ͧ ˹͹͡ҷط ٻͧçѹ


Ҿʴçҧ㹢ͧ ˹͹͡ҷط ٻͧ

4.˹¨¾ѧҹ俿 ( Power supply unit )
       ˹ҷ ѺдѺçѹ俿дѺШѺ ˹»żšҧ , ˹Թط ,
˹ҷط ͡ҡѧçѹ俿Ѻâҧ˹»żšҧ Ѻػó¹͡
Թطҷط(Remote Input / Output Module) , ػó㹡¹
(Programmer) 繵
      
ǹҡ ˹¨¾ѧҹ俿 ͧ ͨԡ͹ ö͡
Ѻçѹ AC ( 120-220 VAC ) DC ( 24-125 VDC ) Ѻͧâͧ ѧ鹶Ҩ
繨еͧ͡кͨԡ͹ Ҥè͡˹¨¡ѧ俿ҷ
ͨӡѴ


Ҿʴ çҧ㹢ͧ ˹¨¾ѧҹ俿

       ʴǹСͺͧ˹¨¾ѧҹ俿 ԴçѹԹط AC çѹ俿
Ѻ ж١ŴҴբҴ ŧŴçѹ (Step-down transformer) ѧҡ çѹ
ŴҴǨж١¹çѹ俿ҡʵç ǧ§ (Rectifier) Ŵáͧ
çѹ ǧáͧѭҳ (Filter) ҡçѹмҹ ǧѡдѺçѹ餧 ¹ŧç
ѹԹط ʷҧҹҷط ǧ ä (Regulator) ͡ҡ ѧǹ˹ҷͧѹ
Ѵǧ (Short circuit protection) ͧѹè¡Թ (Overload protection) Шçѹҷط
բҴ ͨѺ˹µҧ ͧк ͨԡ͹

5.ػó (Peripheral Devices)
            • PROGRAMMING CONSOLE
          • EPROM WRITER
          • PRINTER
          • GRAPHIC PROGRAMMING
          • CRT MONITOR
          • HANDHELD
          • etc
 

ͧ Ե, ,

PLC դӨӡѴ¡ѹ Ե (BIT), 亵 (Byte), (Word) ѡ¡Ф¢ͧФմѧ

1 Word = 2 Byte
1 Byte   = 2 Digit
1 Digit  = 4 Bit

  ŢҴ 256 źԵ (kBit) ö红亵 ?
                        8 Ե               =       1  
                        256 źԵ    =       (256 x 1000)/8            = 32,000   
                                                                                              = 32 

˹¤ Ҵ 6 kWords Ҩ¹˹ kB. ?
                        1 Word           =       2 
                        6 kWord         =       2 x 6 x 1000                =       12,000   
                                                                                              =       12   

 

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