The document discusses programmable logic controllers (PLCs) and their use in industrial automation. It describes the basic hardware components of a PLC system including the power supply module, CPU, input and output modules, and communication modules. The advantages of PLCs are listed as flexibility, fast implementation, low cost, reliability, and energy savings. The document outlines the basic structure and working of a PLC, including how ladder logic is used for programming. Real-world applications in processes like rolling mills are also mentioned.

1. 08/24/1706 / 09 /
2007
PLC 1
INDUSTRIAL AUTOMATION
USING PROGRAMABLE LOGIC
CONTROLLER (PLC)
By: Saumya Ranjan Behura

2. 08/24/17 PLC 2
 transfer of control from man to
machine
 machine intelligence
 interface between hardware and
software
AUTOMATION : what is it?

3. 08/24/17 PLC 3
PLC advantages:
 Flexibility
 Fast implementation
 Low cost
 V.D.U. display
 More reliable
 Reduces space
 Energy saving
 Ease of maintainance
 Economical

4. 08/24/17 PLC 4
PLC HARDWARE STRUCTURE (in
modules)
 Power supply module
 C.p.u./ controller
 Input/output module
 Counter module
 Rack/back plane
 Communication module

5. 08/24/17 PLC 5
Power supply module:
 Calculation of total power before
selection of power module.
 Selection of proper voltage range.
 Regulation of 5v,12v for operation of
electronic components.
 Proper ground connection.

6. 08/24/17 PLC 6
CPU / CONTROLLER :
 Controlling of the logic,logging of
data,fault & history.
 Consists of processor,some memory
chips & a math processor.
 Processor collects the status of input
and writes to PII
 Writes the result in PIQ.

7. 08/24/17 PLC 7
RAM :
 Programme memory
 Timers
 Counters
 Flags
 Process i/o image tables
 System data
 alu

8. 08/24/17 PLC 8
INPUT MODULES :
 Acts as a interface between field
control inputs & c.p.u.
 Volage/current generated by sensors
transducers etc. are applied to the
terminal of input module.
 Converts field signal into a standard
control signal for processing by plc.
 Sends one input at a time to c.p.u.

9. 08/24/17 PLC 9
OUTPUT MODULES:
 Acts as a link b/w C.P.U. & output
devices located in the field.
 Filed devices could be
relays,contactors,actuators etc.
 Converts the signal delivered by cpu
into an appropiate voltage level
suitable for output field devices.
 Both input & output modules can be
analog or digital.

10. 08/24/17 PLC 10
DIGITAL I/O MODULE :
 Mounted on the rack
 Connected with c.p.u.(ribbon cable)
 Connected with c.p.u. in a serial bus.
 Capacity : 8,16,32 i/p
 Voltage :24 V d.c.,110 V a.c.,240 V
a.c.
 Module must match with field device

11. 08/24/17 PLC 11
ANALOG I/O MODULE :
 Used for analog signals
 Two modes of operation- 4-20 mA /
0-10 V.
 Analysing a continuously changing
output through a transducer like
temperature,pressure,speed /
distance.
 Converts analog signal to digital
values that c.p.u. can process.

12. 08/24/17 PLC 12
BUSSES IN PLC:
 Address bus
 Data bus
 Control bus

13. 08/24/17 PLC 13
BLOCK DIAGRAM OF PLC:
POWER SUPPLY MODULE
INPUT MODULES CPU
PROGRAM MEMORY
OUTPUT MODULES
FIELD INPUTS CONTROL [RELAYS, LAMPS ETC]
PROCESS OR MACHINE

14. 08/24/17 PLC 14
INSTALLATION :
 Mount the power supply module near c.p.u.
 Communication must be mounted in the
third slot.
 Maximum 8 no. of modules can be mounted
in one tier.
 Slot no. starts from right of the c.p.u. &
ends at the interface module.
 Power supply & chassis should be grounded
properly.
 Module should only be removed when the
load voltage is off.

15. 08/24/17 PLC 15
WORKING PRINCIPLE OF P.L.C. :
 Bringing the input signal status to the
internal memory of the c.p.u.
 Processing the signal using programme.
 The result of user programmes scans are
then stored in internal memory of c.p.u.
(PIQ)
 At the end of the programme scan c.p.u.
transfers the signal states of the process
image output to the output module &
further to field controls.

16. 08/24/17 PLC 16
Layout Of PLC System:
Field
Signals
INPUT
MODU
LES
CENTRAL PROCESSING
UNIT
INPUT
IMAGE
TABLE
OUTPUT
IMAGE
TABLE
I/O
BUS
USER PROGRAM MEMORY INTERNAL
TIMERS
INTERNAL
COUNTERS
INTERNAL
FLAG BITS
OUT PUT MODULES
IO BUS
FIELD DEVICES

17. 08/24/17 PLC 17
AB PLC PROCESSOR :
SPECIFICATION SLC5/01
1747-L511,
L514
SLC 5/02
1747-
L532
SLC
5/04
1747-
L541
SLC
5/04
1747-
L542
SLC
5/04
1747-
L543
PROGRAM
MEMORY
1K OR 4K
ISTRUCTIONS
4K
INSTRUC
TIONS
12KWOR
DS
28K
WOR
DS
60K
WORDS
MAX.I/O CAPACITY 256 480 960 960 960
TYPICALSCAN TIME 8MS/K 8 4.8 1 0.9 0.9
PROGRAMMING
INSTRUCTIONS
52 71 99 99 99

18. 08/24/17 PLC 18
Programming of PLC :
 Software driven equipment
 Control process is decided by user
program.
 The program is stored in user
memory or program memory.
 C.P.U. sequentially executes the
instruction & operates the control
elements.

19. 08/24/17 PLC 19
PLC SOFTWARE & LADDER
PROGRAMMING :
 AB software- RS logix-5000
 Siemens PLC-SEMANTIC-S7
 Types of programming language:
(1) STL (2) FBD (3)LADDER LOGIC

20. 08/24/17 PLC 20
LADDER LOGIC :
 LADDER ELEMENTS :
Power Rail:two thick lines drawn in the diagram.
Rung :a horizontal which sequences the order of ladder logic execution.
Rung comment :description written above the rung.
Instruction :codes that evaluate the data & perform
computation.
Instruction comment:the desrciptive text for an instruction.
Branch :separate path on a rung.
Loops :are given to tempararily bypass a portion of rung.

21. 08/24/17 PLC 21
Ladder logic diagram :
XIO OTE
XIC - Examine In Closed
XIO – Examine if open
OTE – Output energize
OTL – Output latch
xic

22. 08/24/17 PLC 22
LADDER DIAGRAM 2 :

23. 08/24/17 PLC 23
REAL TIME APPLICATION :

24. 08/24/17 PLC 24
AB & SIEMENS S7 :

25. 08/24/17 PLC 25
CASE STUDY :
APPLICATION OF PLC
IN ROLLING MILLS FOR
PIPE MAKING.

26. 08/24/17 PLC 26
QUESTIONAIRE

27. 08/24/17 PLC 27