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CHAPTER 4 – PROGRAMMING

Main Objective:

Provide an overview of PLC programming method using programming languages commonlyused.

Specific Objectives:

After completed this chapter, student will know the major component

1. Familiarise with the PLC Programming system2. Able to explain PLC programming method using Ladder Diagram and mnemonic

code., Instruction set and logic function.3. Understand and use Ladder Diagram and mnemonic code to solve control systems

circuits.4. Explain the following logic instruction set: Load. Load Not, Out, And, And Not, Or,

Or Not, And Ld and Or Ld.5. Explain sequential instruction set: No Operation, End, Interlock, Jump, Keep,

Set/Reset and Differential Up/Down.6. Explain the timer and Counter instruction set and execute timer/counter application

solution methods.

4.0 Introduction

PLC programming process is to plan activities such as design and write a program to performthe required tasks.

Here are the parts that should be there in a PLC program.

Start Starting an operation

Operating Mode Determining the origin of the device input / output andalso the starting point

The Reset Controlling the operation of start / stop it manually orautomatically in the program

Operations / OrderingProcess

Program design as required by the task

Signal Output Trigger output devices.

Status Output Display indicator light or alarm.

End Stop the process./operation

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4.1 Programming Language

IEC 1131-3 is the international standard for programmable controller programming languages.The following is a list of programming languages specified by this standard:

i. Ladder Diagram (LD)ii. Instruction List (IL)iii. Structured Text (ST)iv. Sequential Function Chart (SFC)v. Function Block Diagram (FBD)

One of the primary benefits of the standard is that it allows multiple languages to be usedwithin the same programmable controller. This allows the program developer to select thelanguage best suited to each particular task.

i. Ladder Diagram

Ladder Diagram is kind of graphical programming language that changed the relay controlwiring circuit diagram. Ladder Diagram contains tracks from left to right contact diagram (seeFigure below). This platform is connected to contact elements available normally open - NO oravailable Normally closed - NC through the current path and loop elements.Ladder diagram also shows the control circuit and the display function and a combination ofthe sequence of operations for each branch of the horizontal lines separately.

Ladder Diagram

Mnemonic Instruction

There are other methods to program PLCs. One of the earliest techniques involved mnemonicinstructions. These instructions can be derived directly from the ladder logic diagrams andentered into the PLC through a simple programming terminal.

ii. Instruction List

This low-level language is similar to Assembly language and is useful in cases where smallfunctions are repeated often. Although it is powerful, it is considered to be difficult to learn.

+ve -veINPUT CONDITION OUTPUT ACTION

NO NC

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Example

Calculate new weight by subtracting tare weight from net weight.

LD weigh_commandJMPC WEIGH_NOWST ENORETWEIGH_NOW: LD gross_weightSUB tare_weight

iii. Structured Text

Structured Text (ST) is a high level textual language that is a Pascal like language. It is veryflexible and intuitive for writing control algorithms.

Structured Text uses operators such as logical branching, multiple branching, and loops. Peopletrained in computer programming languages often find it the easiest language to use forprogramming control logic. When symbolic addressing is used, ST programs resemblesentences, making it highly intelligible to beginner users as well.

ST is ideal for tasks requiring complex math, algorithms or decision-making. Its concise formatallows a large algorithm to be displayed on a single.

Benefits of Structured Text People trained in computer languages can easily program control logic Symbols make the programs easy to understand Programs can be created in any text editor Runs as fast as ladder

Example 1

We have Motor that will be controlled manually by 2 push buttons (Start Push Button, and Stop Push Button).When the Start Push Button is pushed then the Motor will be turned ON. and when the Stop Push Button isPushed then we want to stop the Motor. (Security logic has been taken off this logic, for the purpose ofdomonstration.)

IF StartPb THENMotor := 1;END_IF;IF StopPb THENMotor := 0;END_IF;

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iv. Sequential Function Chart

These are similar to flowcharts, but much more powerful. This method is much different fromflowcharts because it does not have to follow a single path through the flowchart.

SFC programming offers a graphical method of organizing the program. The three maincomponents of an SFC are steps, actions and transitions. Steps are merely chunks of logic, i.e., aunit of programming logic that accomplishes a particular control task. Actions are the individualaspects of that task. Transitions are the mechanisms used to move from one task to another.Control logic for each Step, Action and Transition is programmed in one of the other languagessuch as Ladder Diagram or Structured Text.Is a kind of graphic language (see Figure 4.1.4). Elements are the steps, transitions, choice andparallel branch. Each step shows the status of the control program processes the active orinactive. One step consists of action based on the transition. The action consists of thesequence structure itself.

v. Function Block Diagram

Like SFC, FBD is a graphical language that allows programming in other languages (ladder,instruction list, or structured text) to be nested within the FBD. In FBD, program elementsappear as blocks which are "wired" together in a manner resembling a circuit diagram. FBD ismost useful in those applications involving a high degree of information/data flow betweencontrol components, such as process control.

Step 1 MOTOR (Start)

Step 2

Step 3

MOTOR (Stop)

Transition 1

Transition 2

Action

Sample Program In Sequencial Function Chart Language

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4.1.1 Basic Ladder Diagram

A ladder diagram consists of a vertical line on the left and right are called bus bars andhorizontal lines to the right, called the instruction lines.

Along the lines of command are logical combinations of conditions (conditions) that willdetermine when and how the instructions on the right at all to be implemented.

Based on the picture above, one should note that a ladder diagram consists of two basic parts:left section also called conditional, and a right section which has instructions. When a conditionis fulfilled, instruction is executed.

Example Ladder Diagram as shown in figure below .

instruction00000 0000100002

00003 00004

00005 0000600007

Sample Ladder Diagram

0000700007

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The pairs of vertical lines along the branch line is called the conditions. These conditionsconsist of two, namely:

i. Normally open condition (NO)ii. Normally closed condition (NC)

The numbers in each case to determine the bit operations per instruction. Each command inladder diagram either ON or OFF depending on the status of specified bit operations.

Notes:Normally open condition is ON if the bit operation is ON and will be OFF if the bit operation is OFF .Normally closed condition is ON if the bit operation is OFF and will be OFF if bit operation is ON.

4.2 Basic Terms

4.2.1 Execution Conditions

Logical combination of the ON and OFF states gathered to establish an instruction to beimplemented. This condition is called Execution Condition. Refer to figure below.

Instructions will be in the Execution Conditions ON when IR 00000 is ON, IR 00001 is OFF and IR00002 is ON.

Instructionn

Instructionn

00000

Normally Open

Normally Closed

00000

Instruction executed whenthe IR bit 00000 is ON

Instruction executed whenthe IR bit 00000 is OFF

Example of Ladder Diagram

instruction

00000 00001 00002

Examples of Execution Conditions

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4.2.2 Operand Bits

Bit operations for each instruction can consist of any of the bits in the memory area IR, SR, HR,TC or TR. This means that the conditions in Ladder Diagram can be determined by the bit I / O,flags , work bits , timer / counters and others.Table 4.3.2 shows the memory map refers to the PLC type SYSMAC OMRON-CQM1H.

DATA AREA BIT FUNCTION InputArea

IR00000 -IR01515

Used as the input bit

OutputArea

IR10000 –IR11515

used as output bits.

IR Area

WorkArea

IR21600 –IR21915

Bit has no functionspecifically. Can be usedfreely in the program

SR Area SR24400 –SR25507

This bit use to do certainfunctions, such as flags(flags) and control bits.

TR Area TR 0 – TR 7 This bit is used totemporarily store the statusON / OFF on the branchesof the program

HR Area HR 0000 – HR9915

This bits used to store dataand maintain the status ON/ OFF when the power isoff.

Timer/Counter Area TC 000 – TC 511 The same number used forthe timer and counter. Usefor TC000 to TC002.`interval timer '

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4.2.3 Logic Block

The respond to an instruction is determined by the relationship between the conditions on theinstruction line that connects them. Any group of conditions that formed to produce a logicalresult is called a logical block. Refer to Figure 4.3.3.

4.2.4 Instruction Block

A block of instruction is composed of all the instructions contained in a block. Block is obtainedby drawing a horizontal line without cutting a vertical line and vice versa. Refer to Figure 4.3.3.

4.2.5 Mnemonic Code

Ladder diagram can not be read by the Programming Console. Thus the ladder diagram shouldbe changed to mnemonic code. Mnemonic code provides the same information as ladderdiagram and can be typed directly on Programming Console.

ADDRESS INSTRUCTION OPERASI / DATA00000 LD 0000000001 OR 0000100002 AND 0000300003 AND LD00004 OUT 1000000005 TIM 000

#005000006 CNT 002

#001000007 FUN 01

instruction

00000 00002

00001

00003

Example Logic Block

Example Mnemonic Code

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ANSWER ALL THESE QUESTIONS

1. What do you understand about Ladder Diagram and draw one (1) example of a LadderDiagram.2. Explain the purpose of the following terms:

i. The logic blocksii. The Instruction block

Reference;1. http://www.kronotech.com/ST/st.htm

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UNIT 5: BASIC INSTRUCTIONS SET

OBJECTIVE:

Describe the set of instructions used in PLC programming

SPECIFIC OBJECTIVES:

At the end of this unit student should be able to:

i. Know the functions of the instruction LOAD, LOAD NOT, OUT, AND, AND NOT,OR, NOT and OR END

ii. Know the function block instruction AND LD and OR LD.iii. Convert Ladder diagram to Mnemonic Code.

NOTE: These instructions will be explained later is based on OMRON PLC brands –SYSMAC CQM1H

5.0 Introduction

There are a lot of instructions used to develop the PLC program. Each instruction has arespective function.

5.1 LD - LOAD Instruction

These instructions are use to start a line of the program.It is used in the first contacts in the normally open condition (NO).

Ladder Diagram Mnemonic Code

Explanation:The Execution Conditions of the instruction on the right will be ON when IR 00000 is ON.

instruction00000 Address Instruction Operand/Data

00000 LD 00000

00001 instruction

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5.2 LD NOT - LOAD NOT Instruction

These instructions are use to start a line of the program.It is used in the first contacts in the normally closed condition (NC).


Explanation

The Execution Conditions of the instruction on the right will be ON when IR 00000 is OFF

5.3 AND - AND Instruction

These instructions are used in the second contact in a normally open (NO) and a

series with previous contacts


Explanation

The Execution Conditions of the instruction on the right will be ON when IR 00000 and IR 00001are ON

instruction

n

00000 Address Instruction Operand/Data

00000 LD NOT 00000

00001 instruction

instruction

n

00000 00001 Address Instruction Operand/Data

00000 LD 00000

00001 AND 00001

00002 instruction

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5.4 AND NOT - AND NOT Instruction

These instructions are used in the second contact in a normally closed (NC) and in

series with previous contacts


ExplanationThe Execution Conditions of the instruction on the right will be ON when IR 00000 ON and IR00001 are OFF.

5.5 OR - OR Instruction

These instructions are used in the second contact in a normally open (NO) and in

line (parallel) with previous contacts.

. Ladder Diagram Mnemonic Code

Explanation

The Execution Conditions of the instruction on the right will be ON when either IR 00000 orIR 00001 are ON.

instructionn


00000 LD 00000

00001 AND NOT 00001

00002 instruction

instructionn


00000 LD 00000

00001 OR 00001

00002 instruction

00001

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5.6 OR NOT - OR NOT Instruction

These instructions are used in the second contact in a normally closed (NC) and inline (parallel) with previous contacts


Explanation

The Execution Conditions of the instruction on the right will be ON when either IR 00000 is ONor IR 00001 is OFF or IR 00000 ON, IR 00001 OFF simultaneously

5.7 OUT - OUTPUT Instruction

These instructions are used for the coil output.


IR 10000 will ON when IR 00000 is ON .

5.8 END

END instruction has no physical contact device. It is the last instruction required for completion of a program. If no END instruction, the program cannot be implemented

instructionn


00000 LD 00000

00001 OR NOT 00001

00002 instruction

00001


00000 LD 00000

00001 OUT 10000

10000

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For PLC type OMRON - SYSMAC CQM1H, the instruction FUN 01 is the END instruction.

5.9 OR LD - BLOCK LOGIC OR Instruction

The OR LD instruction has no physical contact device.

Only a programming tool for solving complex OR function as a series of contacts LD (or

LD NOT), in parallel with a series of other contacts.


END


00000 LD 00000

00001 AND NOT 00001

00002 OUT 10000

00003 FUN 01

10000

END


00000 LD 00000

00001 AND 00001

00002 LD 00002

00003 AND 00003

00004 OR LD

00005 OUT 10000

00006 FUN 01

10000

00002 00003

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5.10 AND LD - BLOCK LOGIC AND Instruction

The AND LD no physical contact device.

Only a programming tool for solving complex functions such as AND connects a

number of OR, OR NOT, OR LD in the series.


00001

5.11 OR LD and AND LD

When both logic block instruction is to be used in Ladder Diagram, a program must be

written from the bottom up to merge logic blocks. For example, ladder diagram below:

Logic block of instruction for the last two blocks (blocks b1 and b2 blocks) are written

first and then followed by the first logic block instruction (block a).

END

0000000001

Address Instruction Operand/Data

00000 LD 00000

00001 OR 00002

00002 LD 00001

00003 OR 00003

00004 AND LD

00005 OUT 10000

00006 FUN 01

10000

00002 00003

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Ladder Diagram

Mnemonic Code

Example.

END

00000 000011000000002 00003


00000 LD NOT 00000

00001 AND 00001

00002 LD 00002

00003 AND NOT 00003

00004 LD NOT 00004

00005 AND 00005

00006 OR LD

00007 AND LD

00008 OUT 10000

00009 FUN 01

00004 00005

Block a Block b2

Block b1

Block b2

Block a

Block b1

Block b2 + Block b1 = Block b

Block b, Block a

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UNIT 6 (4.3) : SEQUENTIAL INSTRUCTION SET

Objective

Describe the sequence instruction set NO OPERATION, END, INTERLOCK, JUMP, KEEP, SET /RESET and DIFFERENTIATE UP / DOWN

Specific Objectives:

At the end of this unit you should be able to understand set of instructions the followingsequence:

NO OPERATION

END

INTERLOCK

JUMP

KEEP

SET/RESET

DIFFERENTIATE UP / DOWN

6.0 Introduction

In this unit you will be exposed to a sequence of instructions which usually acts as the lastinstruction in the instruction line.

Instruction sequence SET, RESET, KEEP, DIFFERENTIATE UP, DOWN DIFFERENTIATE, used toON and OFF state output bits in the IR. These instructions are used to control the status of theother bits in the IR or in other areas.

INTERLOCK instruction sequences can overcome the problem of storing execution conditions,in the branches of the ladder diagram.

JUMP instruction sequence can be used to control devices that require a product that can last along time.

6.1 NO OPERATION – NOP ( 00 )

These instructions do not have a ladder diagram symbols and will not do any operations.

When you remove the memory in this instruction will be displayed on the console screen PLCprogramming.

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6.2 END – END(01)

Acting as the last instruction for each program (see figure 6.2) There is no instruction will be written after the END instruction (01) implemented. If there is no END instruction (01) in the program, the task would not be implemented

and verse NO END LIST is displayed on the programming PLC console screen.

Ladder Diagram shows the END instruction

Mnemonic Code

6.3 INTERLOCK [ IL ( 02 ) ] DAN INTERLOCK CLEAR [ ILC ( 03 ) ]

IL (02) and ILC (03) must be used together. These instructions are used to solve the problem of storing execution conditions at

branch points. When the INTERLOCK instruction is ON as shown in Ladder Diagram 6.3, the

implementation of the INTERLOCK instruction will control all of the instructionexecution until the instruction ‘INTERLOCK CLEAR’. When the INTERLOCK instruction isOFF, INTERLOCK CLEAR instruction will reset the program operation.

To set the INTERLOCK instruction for PLC tpe OMRON - SYSMAC CQM1H is FUN 02 forINTERLOCK instruction and FUN 03 is INTERLOCK CLEAR instruction.

00000

END

10000

Address InstructionOperand/Data

00000 LD NOT 00000

00001 OUT 10000

00002 FUN(01)

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00000

00001 10000

Mnemonic Code


00000 LD 0000000001 FUN 02 -00002 LD 0000100003 OUT 1000000004 FUN 03 -00005 FUN 01 -

Referring to Ladder Diagram 6.3,

When the instruction input LD 00 000 is ON, the instruction IL (02) will be ON.

Instruction output OUT 10 000 will depend on the instruction input ON LD 00001 and LD00000.

If the input instruction LD 00 001 ON, output OUT 10000 will be ON.

If the input instruction LD 00 001 OFF, output OUT 10000 will be OFF.

In the event that the input instructions LD 00 000 OFF, instruction IL (02) is OFF.

Instructions to the output OUT 10 000 will be OFF.

Next program ILC (03) will reset the program.

IL (02)

ILC (03)

END

Figure 6.3 : Ladder Diagram shows IL ( 02 ) dan ILC ( 03 )instruction

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Refer the table below:

InstructionsLD 00000

IL(02)

InstructionsLD 00001

Input

InstructionsOUT 10000

Output

ON ONONOFF OFFON OFFOFFOFF OFF

6.4 JUMP [ JMP (04) ] DAN JUMP END [ JME (05) ]

Instructions JMP (04) is usually used in pairs with the command JME (05) for the jump. JMP (04) is a command to determine the starting point of the jump and JME (05) is the

instruction that the direction of the jump.( where to jump). When the instruction JMP (04) is ON, no jump will occur and the program will be

implemented as written. When the instruction JMP (04) is OFF, a jump to the instruction JME (05) which has the

same number will be done. Further instructions are the instructions JME (05) will beimplemented.

Instructions JUMP and JUMP END can use the numbers from the range of 00 to 99. To set the instruction for PLC type OMRON - SYSMAC CQM1H, is FUN 04 for JUMP

instruction and FUN 05 instruction is the JUMP END instruction.

00000

00001 10000

JMP (04)01

JME (05) 01

END

Figure 6.4 : Ladder Diagram shows JUMP instruction

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Mnemonic Code


00000 LD 0000000001 FUN (04) 0100002 LD 0000100003 OUT 1000000004 FUN (05) 0100005 FUN (01) -


• When the input instruction LD 00000 is ON, instruction JMP (04) will be ON.Subsequent instructions will be implemented as written.

If the input instruction LD 00 001 is ON, output instruction OUT 10000 will be ON.If the input instruction LD 00 001 is OFF, output instruction OUT 10000 will be OFF.

• When the input instruction LD 00 000 is OFF, instruction JMP (04) will be OFF. Nextjumps to Instruction JME (05) will occur. All instruction that is between JMP (04) and JME(05) will be ignored.

• Refer to the table below.

Instruction LD 00000JMP(04)

Instruction LD 00001Input

Instruction OUT 10000Output

ON ONON

OFF OFF

OFF Not implemented/executed Not implemented/executed

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6.5 KEEP – KEEP (11)

KEEP instruction is used to maintain the status bit operation based on two stateexecution condition.

KEEP (11) operates like a Latching Relay which is set by S and reset by R.

When S is in the ON state, the operation of a particular product instruction is ONand remain ON until reset, regardless of whether S is ON or OFF.

When R is in the ON state, the operation of a particular product instruction is OFFand remain OFF until reset, regardless of whether R is ON or OFF.

For PLC type OMRON - SYSMAC CQM1H, the instruction FUN 11 is KEEP instruction.

00002

00003

Mnemonic Code

Address Instruction Operand / Data00000 LD 0000200001 LD 0000300002 FUN (11) HR 000000003 LD HR 000000004 OUT 1000400005 FUN (01)

Figure 6.5 : Ladder Diagram shows KEEP instruction

HR0000

KEEP (11)

HR 0000

S

R

END

10004

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With reference to Figure 6.5,

Instruction LD 00 002 acts as S (Set)-and the LD 00 003 acts as R (Reset). When the instruction LD 00 002 ON, the output instruction OUT 10004 will be ON and

will remain ON even if the instruction LD 00 002 is OFF. When the instruction LD 00 003 ON, then the output OUT 10004 instruction OFF and

will remain OFF even though the instruction LD 00 002 in OFF or ON state.

Instruction LD 00003Reset

Instruction LD 00002Set

Instruction OUT 10004Output

ON ONOFF

OFF ON

ON OFFON

OFF OFF

6.6 SET and RESET

SET and RESET instruction will change the status of bit operations only when the

implementation is ON.

In the OFF condition, the instructions will not change the bit operation status.

00000

00001

Figure 6.6 : Ladder Diagram shows the Set and Reset instruction

SET 10000

RESET 10000

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Mnemonic Code

Address Instruction Operand / Data00000 LD 0000000001 SET 1000000002 LD 0000100003 RESET 10000


When the input instruction LD 00 000 is ON, SET instruction command to ON and alwaysON regardless of whether the input instruction LD 00 000 is ON or OFF.

When the inputs instruction LD 00 001 is ON, RESET instruction is ON and SETinstruction will be off .

Its operations can be understood clearly in the KEEP instruction.

6.7 DIFFERENTIATE UP [ DIFU (13) ] DAN DIFFERENTIATE DOWN [DIFD (14) ]

DIFU instructions (13) and DIFD (14) will ON the output within a very short time. Instructions DIFU (13) will turn the output to ON when the input signal changes from

OFF to ON. Instructions DIFD (14) will turn the output to ON when the input signal changes from

ON to OFF. For PLC type of OMRON - SYSMAC CQM1H, instruction FUN 13 is instruction

DIFFERENTIATE UP and FUN 14 is instruction DIFFERENTIATE DOWN.

Input

DIF U

DIF D

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00000

Figure 6.7a : Ladder Diagram shows DIFFERENTIATE UP instruction

Mnemonic Code

Address Instruction Operand / Data00000 LD 0000000001 FUN (13) 0100000002 LD 0100000003 OUT 10000

Referring to Ladder Diagram 6.7a,

When the input instruction LD 00000 is ON (has changes from OFF to ON), operand bit01 000 will be ON, the output OUT 10000 will be ON within a very short time and thenOFF. We can not see the situation in the products.

After that the operand bit 01 000 will be OFF regardless of the status of the inputinstruction LD 00 000.

00000

Figure 6.7b : Ladder Diagram shows the DIFFERENTIATE DOWN instruction

DIFU (13)01OOO

END

01000 10000

DIFU (14)01OOO

END

01000 10000

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Mnemonic Code

Address Instruction Operand / Data00000 LD 0000000001 FUN (14) 0100000002 LD 0100000003 OUT 10000

Referring to Ladder Diagram 6.7b,

When the input instruction LD 00 000 is OFF (change from ON to OFF), operand bit01000 will be ON, the output OUT 10000 will be ON within a very short time and thenOFF. We can not see the situation in the products.

After that the operand bit 01000 will be OFF regardless of the status of the inputinstruction LD 00 000.

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UNIT 7(4.4) : TIMER AND COUNTER

OBJECTIVE:

Describe the instruction set of timer and counter.

SPECIFIC OBJECTIVES:

At the end of this unit you should be able to:

1. Describe the instruction timer (TIMER – TIM)2. Describe the instruction counter (COUNTER - CNT).3. Converts Ladder Diagram to mnemonic code.

7.0 Instruction

TIMER (TIM) and COUNTER (CNT) is the instructions that require numbers TIM / CNT (N) andthe set value(SV). The range of numbers TIM / CNT is from 000 to 511, while the range of setvalues for the TIM / CNT is 0000 to 9999

The numbers TIM / CNT can not be used twice. When a number has been used as definer, suchas number 000 for instructions on TIM / CNT, the number can not be used again.

When a number is defined as the number of TIM / CNT, it can be used as often as required asan operator operand in other instructions from the command TIMER or COUNTER.

7.1 TIMER - TIM

Symbol

Timer numbers (N) is between 000 and 015. The set value (SV) is between 0000 to 9999. All numbers TIM / CNT can be used as definer in only one TIMER or COUNTER

instruction.

TIM N

SV

SV

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Example 7.1.1

TIMER is enabled/activated when the execution condition is ON and will be reset to setvalue (SV) when the execution condition is OFF.

The set value (SV) of TIMER is the BCD between # 0000 to # 9999. For example, if TIMERbe set to 5 seconds, then the set value (SV) is # 0050.

Ladder Diagram

Mnemonic Code


00000 LD 00000

00001 TIM 000

# 0050

00002 LD TIM 000

00003 OUT 10000

00004 FUN 01

Operating Condition:

When the input (LD 00000) is ON, the timer contact will be activated after 5 seconds. Next theoutput (OUT 10000) will be ON

END

00000

TIM 000 10000

Tim 000

# 0050

(5 saat)

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Example 7.1.2

Ladder Diagram

TIM 000 10001

Mnemonic Code


00000 LD 00000

00001 TIM 000

# 0050

00002 LD TIM 000

00003 OUT 10000

00004 LD NOT TIM 000

00005 OUT 10001

00006 FUN 01


When the input (LD 00000) ON, the timer (TIM 000) will be activated after 5 seconds and theoutput (OUT 10000) will be ON. While the output (OUT 10 001) will be ON as soon as the supplyis supplied and will be OFF after 5 seconds. Timer will continue to be active as long as the input00000 state is ON.

END

00000

TIM 000 10000

Tim 000

#0050

(5 saat)

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Example 7.1.3

Ladder Diagram

Mnemonic Code


00000 LD 00000

00001 TIM 000

# 0050

00002 LD TIM 000

00003 AND NOT TIM 001

00004 OUT 10000

00005 LD 10000

00006 TIM 001

#0030

00007 OUT 10001

00008 FUN 01

00000

TIM 000 10000

Tim 000

# 0050

(5 saat)

Tim 001

# 0030

(3 saat)

TIM 001

10000

END

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When the input (LD 00000) ON, the timer (TIM 000) will be activated after 5 seconds. Next theoutput (OUT 10000) will be ON.

After 3 seconds the output (OUT 10000) ON, the timer (TIM 001) will be activated the nextoutput (OUT 10000) will be OFF and the timer (TIM 001) will be OFF.

When the timer TM001 OFF, contact TIM 001 (NC) will be ON and the output (OUT 10000) isON state.

Output (OUT 10000) will continue ON and OFF until the input (LD 00000) in the OFF state.

7.2 COUNTER - CNT

Symbol

Number TIM / CNT can be used as definer for either timer or counter. Counter numbers are range from 000 to 015. Counters are used to calculate the count down from the set value (SV) on the

execution condition on the counting pulse (CP) when it is changed from OFF to ON. The set value (SV) is range 0000 to 9999. Counters will reset to the reset (R).

Ladder Diagram

CP

R

CNT

N

SV

CP

R

CNT 001

# 0010

(10 kiraan)

END

00000

00001

CNT 001 10000

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Mnemonic Code


00000 LD 00000

00001 LD 00001

00002 CNT 000

#0010

00003 LD CNT 001

00004 OUT 10000

00005 FUN 01

Operating Condition

Counter set to count 10. When the input (LD 00,000) is the pulse of ten, a counter will beactivated and thus the output (OUT 10000) will be ON. When reset (LD 00,001) ON, a counterwill be in original condition

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7.3 The Application Of Timer And Counter Instructions

The number of Counter cannot be the same number to the number of timer because bothshare the same data in the PLC memory.

R


Counter set to count 5. When the input (LD 00,000) is the pulse of five, a counter will beactivated and thus the output (OUT 10000) will be ON.

When the output (OUT 10000) ON, TIM 001 will be activated after 3 seconds and then theoutput (OUT 10 001) will be ON.

Both the output (OUT 10000) and (OUT 10 001) will always be ON until reset (LD 00001) in theON state.

Reset will return the counter to its original condition.

CNT 000# 0005

(5kiraan)

CP00000

00001

TIM 001

# 0050

( 5 saat )

END

CNT 000 10000

10000

TIM 001 10001

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