2. WHAT IS A PLC?
A Programmable Logic
Controller, or PLC, is a
ruggedized computer used
for industrial automation.
These controllers can
automate a specific
process, machine function,
or even an entire
production line.
3. ESSENTIAL COMPONENT FOR PLC
SMPS(SWITCH MODE POWER SUPPLY)
NC AND NO SWITCH
CONNECTING LEADS AMD CABLE
RELAY AND CONTACTOR
LOGIC GATES
SOFTWARE
4. SWITCH MODE POWER SUPPLY
A switched-mode power supply
is an electronic power supply
unit. It can act as a switching
regulator to convert electrical
power effectively. These
devices do the transferring of
power from an AC or DC
source to DC loads
WE USE 24V DC SUPPLY TO ON A PLC
5. NORMALLY OPEN SWITCH
A NO contact or a normally open
contact is the one that remains open
until a certain condition is satisfied.
The NO contact in the limit switch
remains open until its actuator is
pressed. When the actuator is pressed
the contact closes and starts
conducting
6. NORMALLY CLOSED SWITCH
A NC contact or normally closed
contact is the exact opposite of
NO contact by function. It
remains closed until a certain
condition is satisfied. It used in a
circuit breaks the circuit or
current flow when its actuator is
pressed.
8. Relay
A relay is an electrically operated switch.
It consists of a set of input terminals for a
single or multiple control signals, and a
set of operating contact terminals. The
switch may have any number of contacts
in multiple contact forms, such as make
contacts, break contacts, or combinations
10. Contactor
A contactor is a device that is for
making and breaking an electrical
power circuit. For example, we
usually use a contactor for turning
on and off an electrical motor.
11. Programming language of plc
1. Ladder Diagram (LD)
2. Sequential Function Charts (SFC)
3. Function Block Diagram (FBD)
4. Structured Text (ST)
5. Instruction List (IL)
12. Ladder logic
The Ladder Diagram is also a graphics oriented programming language
which approaches the structure of an electric circuit. Ladder Diagram
consists of a series of networks. Each network consists on the left side
of a series of contacts which pass on from left to right the condition
"ON" or "OFF" which correspond to the Boolean values TRUE and
FALSE. To each contact belongs a Boolean variable. If this variable is
TRUE, then condition pass from left to right.
13.
14. Timer
PLC timers are internal PLC instructions that can be used to delay input and output
signals in the PLC program
Timer has three bit:
EN: Enable bit:
The Timer Enable (EN) bit is set immediately when the rung goes true. It stays set until
the rung goes false.
TT: Timer timing bit :
The Timer Timing (TT) bit is set when the rung goes true. It stays set until the rung goes
false or the Timer Done (DN) bit is set (i.e. when accumulated value equals preset
value).
DN: Done bit:
The Timer Done (DN) bit is not set until the accumulated value is equal to the preset
value. It stays set until the rung goes false.
15.
16.
17. COUNTER
PLC counters are internal PLC
instructions that can be used to
count input or output signals in
the PLC program.
Counter has three bit:
Count Up bit (CU)
Done bit ( DN)
Overflow (OV)
18.
19.
20. ARITHMETIC OPERATIONS
Arithmetic is the fundamental of mathematics that includes the
operations of numbers. These operations are addition, subtraction,
multiplication and division.
21.
22.
23.
24. LOGICAL OPERATION
A function on binary
variables whose output is
also a binary variable.
Logical operations are
the function of logic
gates in digital circuits.
Logical operations
include AND, OR, NOT,
and combinations of
those operations.
27. SCADA
Basically consists of data accessing feature and controlling
process remotely.
Conversion of data is possible i.e. analog to digital and vice versa.
Can communicate to any of the protocols available in market.
Completely rely on window based operating systems
Distance as such doesn't hamper SCADA operation.
SCADA is not dedicated to any one type of application or
industry.
28. NEED OF SCADA
Previously without SCADA an
industrial process was entirely
controlled by PLC, CNC, PID & micro
controllers having programmed in
certain languages or codes.
These codes were either written in
assembly language or relay logic
without any true animation that would
explain the process running.
Thus to make the understanding
process easily with the help of true
animations SCADA came into
existence.
29. WHAT IS SCADA?
It works like a supervisor who supervises the entire plant area,if needed it also
controls the process as well as it converts the data segments for storing process
values i.e. level, pressure, switch positions, density, temperature, messages, etc.
From a distant place if we want to run the process i.e. starting, stopping,,
opening and closing of field instruments as well as logging the various values.
SCADA can do for you.
SCADA is not a 100% controller it is just a software which has to be linked
with controllers. ultimately it is Ito be connected to PLC/PID / DCS systems
which in turn are connected to field instruments.
Hazardous areas, unhygienic places, hilly areas and sea beds where a person
can't be send regularly but process has to be watched continuously or it should
be controlled then it can be done using SCADA.
31. DYNAMIC REPRESENTATION
This feature explains about the representation of various symbols
of field instruments which are present in tool library which can be
utilized in SCADA applications.
SCADA is not dedicated to any specific industry hence its library
is so large that you can use it for any industries available.
32. DATABASE CONNECTIVITY
SCADA doesn't have its own
database just like Microsoft.
Hence for storage it depends on
databases available in the market.
It can be connected to
VB,SQL,EXCEL or SAP.
33. DEVICE CONNECTIVITY
SCADA is not a 100% controller
i.e. It alone can't run process. It
can be connected to any PLC or
DCS.
Hence any PLC or DCS that are
available in the market by using
specific driver software it can be
connected.
34. ALARMS
Generally alarms are implemented by
indicating lamps or Hooters in field
but SCADA represents it with a
format.
In the field area alarms are generated
for warnings or to keep the process
between certain limits
The format consists of date, time,
status, priorities, many such elements
which can be used for generation of
reports.
35. TRENDS
These are also called as XY plotters or
Data loggers. Basically it represents
the values in wave formats .It is one of
the important feature of SCADA.
It plots the value with reference to
time.
Trend is subdivided into real time and
historical trends. i.e. we can see the
present values of the process as well
past values and can be stored and
records can be maintained for the
same.
36. SCRIPTS
It is the combination of logical
operators which are written in
a statement.
It is used to run the
applications made or stimulate
before final execution.
Various types of scripts make
project execution simpler for
programmer.
37. SECURITY
Every application has to be secured from unauthorized users by
different security levels.
In SCADA this security can be given as a whole as well as
individually.
38. RECIPE MANAGEMENT
One of the finest feature of any SCADA.
It explains that we can maintain various recipes of different
process and implement it on the process.
All the recipes are stored in a single server and it can be fetched
by any client server from any area to run the process.
39. NETWORKING
It explains we can share SCADA applications on LAN or Internet
as well exchange of data is possible.
Many Networking protocols are supported by SCADA software.
SCADA can be put on networking with other peripherals and
processors with various networking topologies.
40. TAGNAMES & TAGTYPES
Every symbol used in software has to be specified name.
The logical name given to any symbol is said to be tag name.
Tag types defines the symbol category. It may be discrete &
analog.
