This document discusses jump instructions in PLC ladder logic. Jump instructions allow a PLC program to break its normal sequential execution and move to another part of the program. The key points covered are: - Jump instructions work with label instructions to redirect program flow. The jump instruction moves execution to the rung with a matching label number. - Jumps can move execution forward or backward within a program. Multiple jumps can target the same label. Jumps can also be nested within other jumps. - Advantages of jumps include allowing a PLC to run multiple programs, jumping sections during faults to reduce downtime, and improving scan time performance. - An example is provided demonstrating a parking lot control system

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LAB REPORT NO.5
INTRODUCTION TO JUMPING
1- Objectives
Upon completion of this lab, one will be able to
 Understand jumping instruction and how it work in plc ladder diagram.
 Use status bits of counters, timers to control other instructions.
 Design example in Online PLC Simulator.
2- PLC Control Instructions
Control instructions are used to enable or to disable a block of the ladder logic program or to
move the execution of a ladder logic program from one place to another place. The control
instructions discussed in this module include the following:
Jump To Label (JMP), instruction format:
Label (LBL), instruction format:
2-1. Jump and Label Instructions
Normally, a PLC executes a ladder logic program in a rung by rung sequence. Jump instruction
is a controlled output instruction that allow a PLC to break this sequence and to move the
program execution to another rung.
Fig.1 Jump instruction

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The Jump to Label instruction and the Label instruction are used in combination to redirect the
execution of a ladder logic program. The Jump to Label instruction is a controlled instruction;
when its rung is false, the PLC scans the next rung. When the rung of a Jump to Label instruction
is true, the PLC breaks its sequence execution and moves to the rung with a Label instruction
that has the same label number as the Jump to Label instruction. When a Label instruction is
used, it is always the first (most left) instruction in a rung. It does not cause its rung to be true or
false; it only shows the location of the label.
jump forward or backward.
use multiple jump to the same label.
Jumps within jumps are possible.
2-2. Advantages of Jump:
Allows the PLC to hold more than one program.
Sections of a program can be jumped when production fault occurs.
Reduces processor scan time, allowing more scans to take place within a given period of
time.
Program information is updated more frequently.
2-3. In Online PLC Simulator:
Jump Instruction JMP:
Label Instruction LBL:

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LAB TASKS:
Task . 1
Logic:
To design such a system, we will require switches, counters, timers and output coils.
Fig.2 Parking system.

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Ladder logic allows this function to be represented this way. Fig.2 shows the actual way in which
the process takes place.
Explanation:
To implement this using ladder logic, we needed NO and NC contacts, timer on-delay instruction
TON, timer off-delay instruction TOFF, UP counters CTU and output coils.
Press the master switch and control system will start operating.
Initially green signal of road-1 is ON and remain ON for 20 seconds, meanwhile the
road-2 has red signal.
After 20sec, road-1 green signal turns off, and red signal gets ON, at the same time road-
2 red signal turns off, and green signal turns ON.
When the green led of any of road gets on, pressing the "Door-1 Open ", car will enter
into parking and the counter value is incremented on the entry of each new car.
After entering the park, pressing the "Door-1 Close” from inside will close the door.
When the parking capacity is maximum i.e. 10, "Parking-1 Full" light will turn on.
Now no more cars will enter the parking lot, and the door will not open for any new car.
Similarly for Parking-2, above 4 steps will repeat.
Setting the timer:
Set Accumulator value equal to zero. Find the preset value and time base value for given time-
delay. If and
Setting the counters:
Set Accumulator value equal to zero. Also set the preset value required.
If and
Simulation:
Login plcsimulator.net and form the ladder logic as:
Addressing the components

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I/O Switches Addresses
Master Switch I/0
G-signal1 O/1
G-signal2 O/12
R-signal1 O/2
R-signal2 O/13
Parking-1 Full O/3
Parking-2 Full O/4
Timer-ON Used T/1
Timer_OFF Used T/0
Door-1 Open I/2
Door-1 Opening Motor O/5
Door-1 Closing Motor O/6
Door-1 Close I/3
Counter for cars in Parking-1 C/1
Door-2 Open I/4
Door-2 Close I/5
Counter for cars in Parking-2 C/0
Door-2 Opening Motor O/7
Door-2 Closing Motor O/8

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Ladder diagram

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Fig.3: I/O panel
To start the simulation, click on RUN. As program starts running, verify the conditions:
Master switch is pressed green signal of road-1 turns on meanwhile signal of road-2 turns
red and T/1 starts and gives a delay of 20 sec.
During 20 sec delay of Green On, Open button is pressed, opening motor will open the
door and car starts entering.

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When parking lot reaches its maximum capacity, Door will not open.

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Conclusion:
Desired system is achieved.
Above simulation & ladder diagram show the logic is correct.