Engineering Skills ECT111/PCT111
Lab Module
UNIVERSITI MALAYSIA PERLIS
COURSE NAME
ENGINEERING SKILLs
COURSE CODE
ECT111/3
PCT 111/3
LAB NO.
LAB MODULE
PROGRAMMABLE LOGIC CONTROL
(PLC)
LEVEL OF COMPLEXITY
1
2
3
4
5
6
KNOWLEDGE
COMPREHENSION
APPLICATION
ANALYSIS
EVALUATION
SYNTHESIS
√
√
√
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Engineering Skills ECT111/PCT111
Lab Module
ENGINEERING CENTRE
CONTENT
INTRODUCTION
LAB 1: Introduction Programmable Logic Controller and Ladder Diagram
LAB 2: Timer and Counter
LAB 3: Introduction to CX-Programmer
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EXPERIMENT 1
Introduction to Programmable Logic Controller (PLC) and
Ladder Diagram
Part A
1.
OBJECTIVE:
At the end of this session you should be able to:
1.1 Explain basic theory behind PLC technology,
1.2 Explain the advantages of PLC compared to relay system, and
1.3 Draw basic circuit conversion from relay system to Ladder Diagram
1.4 Explain types of OMRON PLC available in market,
1.5 Know a simple steps to use Programming Console to program PLC,
1.6 Know about OMRON CPM1A memory structure,
1.7 Understand I/O port addressing in OMRON CPM1A PLC
1.8 Interpret mnemonics code from Ladder Diagram and draw Ladder Diagram
from given mnemonics code, and program PLC with mnemonics code
2.
INTRODUCTION:
PLC definition by National Electrical Manufacturers Association (NEMA):
“A digitally operating electronic apparatus that uses a programmable memory for internal
storage of instructions for implementing specific functions, such as logic sequencing,
timing, counting, and arithmetic, to control, through digital or analogue input/output
modules, various machines or processes”
Figure 2.0: Programmable Logic Controller (PLC)
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2.1 PLC consists of:
a. Input module
b. Output module
c. Processor
d. Memory
e. Power supply
f.
Programming device
Programmable Devices
(Computer or
Programming Console
Figure 2.1: PLC Block Diagram
Inputs: limit switches; push buttons; sensors; other on/off devices;
analogue devices
Outputs: motor; valve; relay; other actuators
CPU: executes logic & sequencing functions; similar to microprocessor of PCs
Memory: stores programs; stores data/status
Power Supply: supplying power for input, output and CPU of the PLC
Programming Devices: programming console, PC
2.2 The PLC works by looking at its inputs and depending upon their state, turning on/off
its outputs. The user enters a program, usually via software, that gives the desired
results.
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2.3 For example, let's assume that when a switch turns on we want to turn a solenoid on
for 5 seconds and then turn it off regardless of how long the switch is on for. We can
do this with a simple external timer. But what if the process included 10 switches and
solenoids? We would need 10 external timers. What if the process also needed to
count how many times the switches individually turned on? We need a lot of external
counters!!
2.4 The bigger the process the more of a need we have for a PLC. Simply program the
PLC to count its inputs and turn the solenoids on for the specified time.
3. WHAT IS THE PURPOSE PLC REPLACE CONVENTIONAL RELAY SYSTEM?
3.1 The main purpose of a PLC is to replace relays circuit.
3.2 Single relay circuitry to represent normally off and normally on output is shown in
Figure 3 and 4 below:
12 V
24 V
Relay
1
2
5
3
4
OUTPUT
motor
INPUT
Figure 3.0: Basic Relay Circuit to Represent Normally Off Output
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12 V
Relay
1
2
OUTPUT
5
3
4
motor
INPUT
24 V
Figure 3.1: Basic Relay Circuit to Represent Normally On Output
3.3 As depicted in Figure 3 and 4, output motor only reacts at single input. More
combinational of input (e.g. two switches to control the motor) requires more complex
of circuitry.
3.4 To reduce circuitry complexity, PLC is used. Figure 3 and 4 can be called in PLC term
as ‘normally open input’ and ‘normally close input’, respectively. The symbols of these
‘contact’ are shown in Figure 5.
(a) Normally open input
(b) Normally close input
Figure 3.2: Relay Circuitry Representation in PLC
3.5 Advantages of PLC over relay system are:
3.5.1
Reduce wiring work
3.5.2
Relays and hardware timers are greatly reduced
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3.5.3
Lab Module
Modification can be quite easy without changing of I/O wiring, if no additional
input or output devices are required
3.5.4
Self diagnostic functions enable easy and fast troubleshooting of the system
4. RELAY CIRCUIT CONVERSION TO LADDER DIAGRAM.
4.1 Normal relay circuit can be represent by using switch symbol as shown in Fig. 6 in the
left side below.
4.2 In relay circuit, input is called as ‘contact’ whereas output is called as ‘coil’.
4.3 In PLC terminology, the relay circuit can be represent by using Ladder Diagram that
connect the corresponding ‘contact’ in the same manner as in relay circuit.
4.4 The coil (output) is generalized as circle symbol that could be lamp, motor, etc.
4.5 Each line of ladder diagram is called ‘rung’ that start with the uppermost as the first
rung. The execution of program inside PLC always starts with the first rung.
4.6 To indicate ‘end of program’ in PLC, the symbol END must be used to avoid errors in
program compilation.
(a)
1st rung
Equivalent to
2nd rung
(b)
Equivalent to
1st rung
6 rung
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Engineering Skills ECT111/PCT111
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NOTE:
The terminology used in this manual is slightly different from relay terminology but the
concepts are the same.
Table 4.0: Relay – PLC Terminology
Relay terminology
Contact
Coil
Normally Open Relay
Normally Close Relay
PLC terminology
Input
Output
Normally Open condition
Normally Close condition.
5. PLC LADDER PROGRAMMING
A very commonly used method of programming PLCs is based on the use of ladder
diagrams. Writing a program is then equivalent to drawing a switching circuit. The ladder
diagram is consists of two vertical lines representing the power rails. Circuits are connected
as horizontal lines, i.e. the rungs of the ladder, between these two verticals.
In drawing a ladder diagram, certain convections are adopted:
1. The vertical lines of the diagram represent the power rails between which circuits are
connected.
2. Each rung on the ladder diagram defines one operation in the control process.
3. A ladder diagram is read from left to right and from top to bottom, Figure 5.0 showing
the scanning motion employed by the PLC. The top rung is read from left to right.
Then the second rung down is read from left to right and so on. When the PLCs is in
its run mode, it goes through the entire ladder program to the end, the end rung being
clearly denoted, and then clearly resumes at the start. This procedure of going
through all the rungs of the program is termed a cycle.
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RUNG 1
RUNG 2
RUNG 3
RUNG 4
END
FIGURE 5.0
4. Each rung must start with an input or inputs and must end with at least one output.
The term input is used for a control action, such as closing the contacts of a switch,
used as an input to the PLC. The term output is used for a device connected to the
output of a PLC, e.g. a motor.
5. Electrical devices are shown in their normal condition. Thus a switch which is normally
open until some object closes it is shown as open on the ladder diagram. A switch that
is normally closed is shown closed.
6. However as to read a ladder diagram which are complete with all the input contacts
and outputs, one must comply with the rule of reading one rung at a time. For
example, please see the figure below:
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1
01000
0.01
0.02
0.04
RUNG 1
0.03
3
2
RUNG 2
END
 Rule No 1: Read the ladder diagram from left to right. Starting from the most left
of RUNG 1, (read through the arrow 1) the first contact will be read as LD 0.01, next
move to the next contact and as the contact is connected in serial, it will be read as
AND 0.02.
MNEMONIC CODE
LD 0.01
AND 0.02
(0.1)
 Rule No 2: Settle the lower LEFT contacts before continuing with the rest of the
rung. As arrow no 1 comes to an end, follow arrow no 2. As the contact 0.03 is
connected in parallel with contact 1 and 2, it will be read as OR 0.03
OR 0.03
(0.2)
 Rule No 3: Continue with the rest of the rung accordingly and comply with Rule
No 1 and Rule No 2. Continue with arrow no 3. As contact no 4 is placed serial, it will
be read as AND 0.04 and finally you reach the end of RUNG 1. As the coil/output is
placed and there. It will be read as OUT 01000. Go on to the second and final RUNG
where the end rung is being denoted.
AND 0.04
OUT 01000
END
(0.3)
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FINAL MNEMONIC CODE
ADDRESS INSTRUCTION OPERAND
00000
LD
00001
00001
AND
00002
00002
OR
00003
00003
AND
00004
00004
OUT
01000
00005
END
BASIC LADDER LOGIC
outputs
inputs
POWER
NEUTRAL
POWER NEEDS TO FLOW THROUGH THE INPUTS TO THE OUTPUTS
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6.0 SWITCHES
6.1 In real world, there are varieties of switch that can be used as input to the PLC.
6.2 The switch may be normally open (NO) or normally closed (NC) and may be activated
from many sources.
6.3 Figure 7 shows the symbols for push-button switches. Both the NO and NC types are
employed. These switches are typically used for operator Input such as to stop and/or to
start a system.
Figure 5.0: Symbols for Limit switches
6.4 Besides representing switches, PLC can be used as timer to control time dependant
task or even as counter for counting task. In most of PLC nowadays, the PLC also
capable to perform floating-point mathematical operations.
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6. INTRODUCTION TO OMRON CPM1A
6.1 There are 4 types of PLC from CPM1A family that differs from it’s no. of I/O:
a) 10 I/O ports (expansion not possible)
b) 20 I/O ports (expansion not possible)
c) 30 I/O ports (with expansion port)
d) 40 I/O ports (with expansion port)
6.2 In each category above, there are two categories of them again; using AC power
supply & DC power supply for the central processing unit (CPU).
6.3 Like other family, CPM1As are programmable via two ways:
6.3.1
Programming console (CQM1-PRO01-E)
6.3.2
PC by using CX-Programmer (through RS-232C adapter)
Programming
Console
CQM1-PRO01-E
(with connecting
cable)
Figure 6.0: Connection diagram between OMRON CPM1A & Programming Console
Figure 6.1: Connection diagram between OMRON CPM1A & PC
6.4 In this lab, we will use CPM1A-20CDR-A-V1, that have 20 I/O (12 input terminals & 8
output terminals) with AC power input for the CPU.
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6.5 This PLC comes with Programming Console CQM1-PRO01-E for programming and
RS-232C adapter (CPM1-CIF01) to communicate with PC. The PLC was packaged
inside Training Kit that occupy 2 modes of usage; LAMP or SOCKET.
6.6 If the mode is selected to LAMP, all the 12 red switches and 8 lamps will be functional
for training & demonstration purposes whereas in SOCKET mode, all the 12 input
ports & 8 output ports on the Training Kit are activated and ready to connect to the I/O
peripherals such as switch, coil, lamp, or even 7 segment display.
7.0 PROGRAMMING CONSOLE CQM1-PRO01-E
LCD
Display
Mode Selector
Keypad
Figure 7.0: Programming Console CQM1-PRO01-E
7.1 Programming Console is the best solution for onsite application such as start up and
adjustments where PC contribution is nearly impossible.
7.2 Usually used by technicians to start or stop certain operation in production line or to
modify data that doesn’t involve directly in main program.
7.3 Have 3 modes of operation (selectable using key provided):
7.3.1
Run
– use to execute the program that has been entered into the PLC. No
changes can be made to the internal data in this mode.
7.3.2
Monitor – use when changing the contents of memory areas while the PLC is
actually in operation.
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7.3.3
Lab Module
Program – for preparing program/modifications/corrections to existing
program.
8
OMRON CPM1A MEMORY AREA STRUCTURE
8.1 Like other programmable devices such as microprocessors and microcontrollers,
PLC has its own memory area that takes part in data processing from bit
manipulations to I/O activities.
8.2 These memory areas were determined by manufacturer and it is standard for all
OMRON PLC in certain family such as CPM1A and CPM2A.
8.3 Every component in Ladder Diagram must have its own address so that there will
be no errors thrown by PLC while compiling the program written.
8.4 In Table 8.0, these memory areas are described in detail for usage in program
development.
Table 8.0: CPM1A Memory Areas
Data Area
Input area
Output area
Work area
(IR area)
Words
000 to 009
(10 words)
010 to 019
(10 words)
IR 200 to IR 231
(32 words)
SR area
SR 232 to SR 255
(24 words)
TR area
---
HR area
HR 00 to HR 19
(20 words)
AR area
AR 00 to HR 15
(16 words)
LR area
LR 00 to LR 15
(16 words)
Bits
00000 to 00915
(160 bits)
01000 to 01915
(160 bits)
IR 20000 to IR
23115
(512 bits)
SR 23200 to SR
25515
(384 bits)
TR 0 to TR 7
(8 bits)
HR 0000 to HR
1915
(320 bits)
AR 0000 to HR
1515
(256 bits)
LR 00000 to
LR1515
(256 bits)
Function
These bits can be allocated to the
external I/O terminals.
Work bits can be freely used within
the program.
These bits serve specific functions
such as flags and control bits.
These bits are used to temporarily
store ON/OFF status at program
branches.
These bits store data and retain
their ON/OFF status when power
is turned off.
These bits serve specific functions
such as flags and control bits.
Used for a 1:1 data link with
another PC.
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Timer/Counter
area
DM
Read/wri
area
te
Error log
Readon
ly
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Lab Module
TC 000 to TC 127 (timer/counter
numbers)
DM 0000 to DM
--0999
DM 1022 to DM
1023
(1,002 words)
DM 1000 to DM
--1021
(22 words)
DM 6144 to DM
6599
(456 words)
---
The same numbers are used for
both timers and counters.
DM area data can be accessed in
word units only. Word values are
retained when the power is turned
off.
Used to store the time of
occurrence and error code of
errors that occur. These words can
be used as ordinary read/write DM
when the error log function isn’t
being used.
Cannot be overwritten from
program.
I/O PORT ADDRESS
9.0 For OMRON PLC, the conventional used for I/O addressing is based on per
channel where each channel size is 16 bits (1 word). Each bit was mapped
exclusively for each port accordingly.
9.1 From Table 2, there are 10 channels (or words) used for input and 10 channels
for output. All input and output devices connected to the PLC must be assigned
with PLC address, correspond to PLC internal memory Input Bit and Output Bit.
9.2
PLC addressing comprises of Channel and Bit. Each Channel consists of 16 bits,
indicated as “00, 01, 02, 03 … up to 15” in the addressing.
9.3
I/O port addressing is illustrated in Figure 9.0 . Note that, usually the “.” Is omitted
for simplification
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XXX. XX
Channel
000.00
Bit
000.01
000.02
Figure 1: PLC I/O Address
Figure 9.0: PLC I/O Address
9.4 In our case, where 12 inputs and 8 outputs involve, the addressing are shown in
Table 3.
9.5 Note that for input and output channel, only channel 000 (input) and 010 (output)
will be used since our PLC used for this lab only have 12 input ports and 8 output
ports. The remaining channels are reserved for other models that have greater
number of I/O.
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Table 9.1: I/O Addressing
I/O
Input
Channel
000
Bit
00
01
02
03
:
:
11
Address
00000
00001
00002
00003
:
:
00011
010
00
01
02
03
:
:
07
01000
01001
01002
01003
:
:
01007
Output
10 PROGRAMMING STEPS
10.1 Starting up
10.1.1 After plugging in the Programming Console at the PLC, switch on the
power supply.
10.1.2 To gain access to the PC’s programming functions, you must first enter the
password. The password prevents unauthorized access to the program.
10.1.3 The PLC prompts you for a password when PLC power is turned on or, if PLC
power is already on, after the Programming Console has been connected to the
PC. To gain access to the system when the “Password!” message appears,
press CLR and then MONTR. Then press CLR to clear the display.
10.1.4 Once the Programming Console has been connected, its mode selector can be
used to change the PLC operating mode. The mode display (<PROGRAM>,
<MONITOR>, or <RUN>) will appear on the Programming Console screen.
10.1.5 Press CLR to clear the display so that key operations can be performed.
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Figure 10.02: PLC Mode Selection
10.2 Clearing memory
10.2.1
This operation is used to clear all of memory, including the user program, PC
Setup and all data areas. This process should be execute only in Program
Mode.
10.2.2 Before beginning to program for the first time or when installing a new program,
all memory areas needs to be cleared.
Figure 10.13: Key is change to Program mode
10.2.3 To begin,
10.2.3.1 Press CLR key to bring up the initial display.
10.2.3.2 Press the SET, NOT and then the RESET Key to begin the operation.
Figure 10.24: To clear memory
10.2.3.3 Press the MONTR Key to clear memory.
Figure 10.35: Press Monitor key
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11.0 ENTERING NEW PROGRAM
11.1 This operation is used enter or edit programs. It is possible in PROGRAM mode
only.
Figure 11.0 6: Change key to Program mode
11.2 The same procedure is used to either input a program for the first time or to change a
program that already exists. In either case, the current contents of Program Memory is
overwritten.
11.3
The program shown in the following diagram will be entered to demonstrate this
operation.
00002
00003
00003
00002
00004
00001
END
Address
01000
00200
00201
00202
00203
00204
Instruction
LD
AND
AND
OUT
END
Operands
00002
00003
00004
01000
Figure 11.17: Ladder diagram and mnemonic code example
11.2.1 Press the CLR Key to bring up the initial display. Note that the 00000 is the address
location of the program.
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Figure 11.28: Show initial display
11.2.2 Specify the address where the program will begin.
11.2.3 Input the address where the program will begin and press the Down Arrow Key. It
is not necessary to input leading zeroes.
Figure 11.39: Entering address
Note: It is a good habbit to start a new program at address 00000
to prevent any problem and difficulties in troubleshooting.
11.2.4 Input the first instruction and operand.
Figure 11.410: Entering first Operand
11.2.5 Press the WRITE Key to write the instruction to Program Memory. The next
program address will be displayed.
Figure 11.511: First operand successfully entered
If a mistake was made inputting the instruction, press the Up Arrow Key to return to
the previous program address and input the instruction again. The mistaken
instruction will be overwritten.
11.2.6 Press AND + 3 + WRITE for the next instruction.
11.2.7 Press AND + 4 + WRITE for the next instruction.
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11.2.8 Press OUT + 1000 + WRITE for output.
11.2.9 To put an END, press FUN + 01 + WRITE.
12.0 CHECKING MEMORY STATUS
12.1 This operation is used to check bits ON or OFF and is useful when debugging the
program or checking input/output wiring. It is possible in MONITOR or PROGRAM
mode only.
Figure 12.012: Modes for checking bits ON or OFF
12.2 The steps are:
12.2.1 Press CLR Key to bring up the initial display, 00000.
12.2.2 Press SHIFT + CONT + <ADDRESS> + MONTR. The address is the
memory location that needs to be checked. For example, to check the
memory location of 00001, the input 1.
Figure 12.113: Check memory location
12.2.3 The status of the input switch (in this case) is shown as ON if the
switch is on and shown as OFF if the switch is off.
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PART B
1.0 LADDER DIAGRAM & MNEMONIC CODE
1.1 Basic Programming Instructions: LD, AND, OR, NOT, OUT, END, AND LD, OR LD.
LD
- A starting instruction for a logic line
Example:
When a logic line starts with an NO (Normally Open) input, use LD.
Ladder Diagram
Mnemonics Code
Figure1.0: LD instruction
AND
Example:
Ladder Diagram
- This is used to connect two or more inputs in serial
Mnemonics Code
Figure 1.1: AND instruction
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1.2 Basic Programming Instructions: LD, AND, OR, NOT, OUT, END, AND LD, OR
LD.
OR
- This is used to connect two or more inputs in parallel
Example:
Ladder Diagram
Mnemonics Code
Figure 1.2: OR instruction
NOT
-
NOT invert its inputs; Often used to form an NC
(Normally Closed) input or output.
NOT can be used with LD, OUT, AND or OR
Example:
Ladder Diagram
Mnemonics Code
Figure 1.3: NOT instruction
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OUT
Lab Module
- This is used to connect output/ designated operand bit
2.3 Basic
Programming Instructions: LD, AND, OR, NOT, OUT, END, AND LD, OR LD.
Example:
Ladder Diagram
Mnemonics Code
Figure 1.4: OUT instruction
END
- This is used to indicate the end of program.
Note: The last instruction in any program must be an End
Instruction.
Example:
Ladder Diagram
Mnemonics Code
Figure 2.2: END instruction
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3.0 NORMALLY CLOSE VS NORMALLY OPEN
3.1 Normally close,
and normally open,
are the advantage of
programmable devices that invert the operation each of them easily only by
programming task that does not involve of any wiring process.
3.2 Consider the following ladder diagram,
00000
01000
END
Figure 3.0: Simple ladder diagram
To make the output 01000 on, the normally open input 00000 should be closed (pull
down)
3.3 Consider the following ladder diagram,
00000
01000
END
Figure 3.1: Simple ladder diagram
To make the output 01000 on, the normally close input 00000 should be open (pull
up)
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3.4 Consider the following ladder diagram,
00000
01000
END
Figure 3.2: Simple ladder diagram
The ‘normally on’ output 01000 will be off if the input 00000 is close (pull down)
3.5 Do not get confuse with normal terms on switch
“A switch should be closed to turn on the lamp”
“A switch should be on to turn on the lamp”
Because PLC is a programmable device that can program the state of a switch itself!!!
4.0 SELF-HOLDING CIRCUIT
START
STOP
MOTOR
MOTOR
Figure 4.0: Self-holding circuit
The explanation for the above circuit, can only obtained from class. Therefore, do not absent.
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5.0 INTERNAL RELAYS
In PLC’s there are elements that are used to hold data, i.e. bits, and behave like relays,
being able to be switched on or off and switch other devices on or off. Hence the term internal
relay. Such internal relays do not exist as real-world switching devices but are merely bits in
the storage memory but behaved in the same ways as relays. For programming, they can be
treated in the same way as an external relay output and input. Thus inputs to external
switches can be used to give an output from an internal relay. This is then results in the
internal relay contacts being used, in conjunction with other external input switches to give an
output, e.g. activate a motor.
Figure 5.1 below shows a ladder program for multiple input conditions.
00001 00002
20000
00003
20000 00004
01000
END
Tips : Bear in mind operands for internal relays start from bits 20000 until 23115 (refer to
table 8.0)
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6.0 Basic Programming Instructions: LD, AND, OR, NOT, OUT, END, AND LD, OR LD.
Example:
Ladder Diagram
Block ‘a’
Mnemonics Code
Block ‘b’
Block ‘a’
Block ‘b’
Combination
of Block “a”
& “b”
Figure 5.0: AND LD instruction
Example:
Ladder Diagram
Mnemonics Code
block ‘a’
Block ‘a’
Block ‘b’
Combination
of block ‘a’
and ‘b’
Figure 5.1: OR LD instruction
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LAB EXERCISE 1 (TO DO INSIDE LAB): INTRODUCTION TO PLC
1. By using Programming Console given in the lab, follow the instruction below to
program the PLC by given Mnemonics Code.
a)
Plug in the given Programming Console cable at the PLC.
b)
Switch on the power supply switch.
c)
PWR LED at the PLC should be turned on while COMM LED should be blinking
to indicate communication between PLC and Programming Console.
d)
Switch to Program Mode by turning the key to Program selection.
e)
If you are asked about password, press CLR + MONTR + CLR at the
Programming Console.
f)
Press CLR + SET + NOT + RESET + MONTR + CLR at the Programming
Console. This is for clearing any program inside the PLC memory.
g)
Verify that there are no program left inside the PLC by pressing ↑ and ↓.
h)
Press LD + 00003 + WRITE.
i)
Press AND + 00002 + WRITE.
j)
Press OUT + 01000 + WRITE
k)
Press FUN + 01 + WRITE.
l)
Switch to Monitor Mode by turning the key to Monitor Mode selection.
m)
Try to close (pull down) and open (pull up) the inputs and watch the output 0.
n)
Draw the equivalent Ladder Diagram and relay circuit for the program that you
have just entered by using the Programming Console. Give explanations.
2. Repeat all the steps in Question 7 by replacing step i) with:
a. Press OR + 00002 + WRITE.
3.
Differentiate Run, Monitor and Program Mode in the PLC used in the lab.
4. Give addresses for input and output for the PLC used in the lab.
5. Give range of addresses for timer/counter.
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UNIVERSITI MALAYSIA PERLIS
COURSE NAME
ENGINEERING SKILLS
COURSE CODE
ECT111/ 3 PCT111/3
LAB TASK
1
LAB TASK 1
LAB TASK 2
PROGRAMMABLE LOGIC CONTROL
(PLC)
NAME
MATRIX NO
COURSE
GROUP
SUBMISSION
DATE
MARKS
LAB TASK 1
LAB TASK 2
TEST
TOTAL MARKS
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Engineering Skills ECT111/PCT111
Lab Module
LAB TASK 1: INTRODUCTION TO PLC
ANSWER ALL QUESTIONS
1. What is Ladder Diagram? Explain briefly.
(2 marks)
2. There are two types of contact in ladder diagram. Name both of them, give explanation and draw the symbol.
i)
ii)
(8 marks)
3. Draw the ladder diagrams for the electrical circuits given below :
The Electrical Circuits
a)
The Ladder Diagram
a)
b)
b)
( 10 marks)
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Engineering Skills ECT111/PCT111
Lab Module
By using Programming Console and CX Programmer, program the PLC with the following
Ladder Diagrams (from questions 4 – 9). First, complete the mnemonics code table, and then
key in the program using Programming Console. Check your program by toggling the
switches.
4.
(10
marks)
Address
Instruction
Operands
5.
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Engineering Skills ECT111/PCT111
Address
Lab Module
Instruction
Operands
(10 marks)
6.
(10 marks)
Address
Instruction
Operands
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Engineering Skills ECT111/PCT111
Lab Module
7.
(10 marks)
Address
Instruction
Operands
8.
(10 marks)
Address
Instruction
Operands
00005
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Engineering Skills ECT111/PCT111
Lab Module
9.
(10 marks)
Address
Instruction
Operands
Convert the following Mnemonics Code (questions 10 and 11) below to its equivalent
Ladder Diagram.
10.
Address
00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
Instruction
LD
LD
LD
AND
OR LD
AND LD
LD
LD
AND
OR LD
AND LD
OUT
END
Operands
00000
00001
00002
00003
00004
00005
00006
01000
(10 marks)
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Engineering Skills ECT111/PCT111
Lab Module
11.
Address
00000
00001
00002
00003
00004
00005
00006
00007
00008
00009
Instruction
LD
LD NOT
AND
LD
AND NOT
OR LD
AND LD
AND
OUT
END
Operands
00000
00001
00002
00003
00004
00005
01004
(10 marks)
Total Marks:
/100 marks
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Engineering Skills ECT111/PCT111
Lab Module
EXPERIMENT 2
TIMER AND COUNTER
1.
OBJECTIVE:
1.1 To understand Timer and Counter operation.
1.2 To apply Timer and Counter concept in PLC programming
2
INTRODUCTION TO TIMER
2.1 From Table 3, CPM1A have 128 timers/counters that can be used for any
applications.
2.2 Below is the basic Ladder Diagram for timer to trigger an output after 8 seconds of
activation.
TIM000
#080
00000
TIM000
Address
Instruction
Operands
00000
00001
00002
00003
00004
00005
LD
TIM
00000
000
#080
TIM 000
01000
LD
OUT
END
01000
END
Figure 2.1: Switching an Output after 8 Seconds
2.3 Example:
2.3.1
2.3.2
2.3.3
Develop the ladder logic that will turn on an output light, 15 seconds after
switch A has been turned on. Give the mnemonic code.
Design another ladder diagram that will turn off the output 01000 after 8
seconds the input 00000 is closed (pull down). Give the mnemonic code.
What if the initial condition of the output 01000 is off? Give your mnemonic
code.
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Engineering Skills ECT111/PCT111
Lab Module
3.0 INTRODUCTION TO COUNTER
3.1 From Table 3, CPM1A have 128 timers/counters that can be used for any
applications.
3.2 Below is the basic Ladder Diagram for counter (10 times).
00000 count
input
CNT001
00002
reset
CNT001
01002
Address
Instruction
Operands
00000
00001
00002
00003
00004
00005
00006
LD
LD
CNT
00000
00002
001
#0010
CNT001
01002
LD
OUT
END
END
Figure 14: Counter Operation.
3.3 Example
3.3.1 Develop the ladder logic that will turn on a light (01004), after switch A (00002)
has been closed 10 times. Push button B (00003) will reset the counters.
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Engineering Skills ECT111/PCT111
Lab Module
Name
:
______________________________
Date: ______________
Matrix No
:
______________________________
Group: _____________
LAB TASKS 2: TIMER & COUNTER.
DESIGN AND APPLICATION PROBLEM
1. Refer the circuit below,
S1
S2
A
L
L
TIM
L
000
#0050
TIM000
IR
END
Read all questions. For question i-iv, EXCLUDE
A
i.
How many rung available at the above circuit?
ii.
What is mean by IR (internal relay)?
iii.
Rung number 1 is also known as a “holding circuit”. Inspect what is
“holding circuit” and briefly, explain.
iv.
Explain how the circuit works.
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Engineering Skills ECT111/PCT111
For question v-vi, consider
Lab Module
A
v.
__
What happened if IR positioned at
vi.
Use your own address, Get the final mnemonic code.
A
? Explain in detail.
*IR = internal relay (20000), L=lamp (output)
Address
Instruction
Operand
(20 marks)
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Engineering Skills ECT111/PCT111
2.
Lab Module
Refer to ladder diagram below,
S1
TIM000
Address
Instruction
Operand
#0050
TIM000
TIM001
01000
01001
01002
S1
TIM001
#0050
END
i.
How many timer uses in the circuit above?
ii. Toggle down switch S1. Wait for __ second. What happened to 01000?
iii.
Toggle up switch S1. Wait for __second. What happened to 01000?
iv. The circuit above also known as “ON and OFF Delay Circuit”. Do you agree?
Why?
v. Give your own address, write the mnemonic code at the given table above.
(20 marks)
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Engineering Skills ECT111/PCT111
Lab Module
3. Answer all questions below. Draw the ladder diagram
a) Toggle switch 00000 for 5 times, after 5 seconds output 01000 turns ON. Draw the
ladder diagram.
(5 marks)
b) Toggle down switch 00001, after 5 seconds output 01002 turns ON. Toggle switch
00002 5 times to OFF output 01002. Draw the ladder diagram.
(5 marks)
c) Toggle down 00000, output 01002 turns ON. After 10 seconds, output 01002
automatically turns OFF. Draw the ladder diagram.
(10 marks)
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Engineering Skills ECT111/PCT111
Lab Module
d) Toggle down 00000, output 01002 turns ON. Toggle for 5 times to OFF output
01002. Draw the ladder diagram.
(10 marks)
e) You are given reference as below:
TIM000 = 10 s
TIM001 = 10 s
TIM002 = 10 s
OUTPUT = 01000
Draw ladder diagram to ON 01000 after 30s.
(10 marks)
f)
You are given reference as below:
CNT000 = 5
CNT001 = 10
OUTPUT = 01000
Toggle 5 times to ON 01000. Toggle another 5 times to off 01000. Draw ladder
diagram.
(10 marks)
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Engineering Skills ECT111/PCT111
Lab Module
g) Use push button. Toggle switch 00003, output 01001goes ON. After 5 seconds,
output 01002 goes ON. 5 seconds after 01002 ON, all output must be OFF
automatically.
(10 marks)
Total marks:
/100 marks
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Engineering Skills ECT111/PCT111
Lab Module
EXPERIMENT 3
Introduction to CX-Programmer
1.
OBJECTIVE:
1.1 know basic step to program PLC using CX-PROGRAMMER
2.
INTRODUCTION TO CX-PROGRAMMER
Figure 3.0: Cx-programmer version 5.0
2.1 CX-Programmer is a PLC programming tool for the creation, testing and maintenance of
programs associated with OMRON CS/CJ/CP-series PLCs, CV-series PLCs and C-series
PLCs.
2.2 It provides facilities for the support of PLC device and address information and for
communications with OMRON PLCs and their supported network.
2.3 It is based on graphical user interface that will help user in creating simple program, or
even very complex program only by using mouse.
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Engineering Skills ECT111/PCT111
Lab Module
2.4 With CX-Programmer, user can create new program from Ladder Diagram. Thus, this will
give greater understanding while in debugging, plus good debugging technique provided.
Figure 3.1: CX-Programmer Main Interface
Figure 3.2: Toolbar for creating Ladder Diagram
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Engineering Skills ECT111/PCT111
Lab Module
Figure 3.3 : Toolbar for Work Online, PLC Monitoring, Transfer to PLC, Transfer from PLC,
Program, Debug, Monitor and Run Mode, Respectively.
LAB TASK 3
1. Repeat Lab Task 2 by using CX-Programmer. Verify your answer.
2. Design problem will be given in the lab later.
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