PLC Architecture

v Input Module

                                 Which interface the field Input device and CPU.

v Output Module

                                 Which interface C.P.U and Output devices.

v C.P.U

                    CPU is a micro controller chip which is fully controlled by the instruction / program stored in user program memory.

              CPU consist of :-

Ø       ALU

Ø      Program Memory.

Ø      Process Image memory.

Ø      Internal timers and Counters.

Ø      Flags

  

v Bus system

Ø     Address Bus:-Address Bus is used to send the address of locations for accessing stored data.

Ø     Data Bus:- Data Bus is used for Data transfer between I/P module to CPU and CPU to O/P Module. 

Ø     Control bus :-Controlling to instructions,timers,counters etc

v Power supply

                                The power supply generates the voltage required for the electronic module of the PLC from the main supply.