Select a suitable Sensor / Switch for a given Process Variable and activate • Selection of Sensor/Transducer – 10 Marks • Activation and Result –20Marks OR Select a suitable motor for the given case and energize • Selection of the Motor – 10 Marks • Energize and Result – 20 Marks Device and Simulate a ladder diagram for the given Case Study • Writing Ladder Program –30 Marks • Simulate and Troubleshoot –20 Marks

1. Vidya Vikas Educational Trust (R),
Vidya Vikas Polytechnic
27-128, Mysore - Bannur Road Alanahally, Alanahally Post, Mysuru, Karnataka 570028
Prepared by: Mr Thanmay J.S, H.O.D Mechanical Engineering VVETP, Mysore Page | 64
Theory and Practical for week 09
Develop PLC program for the following application
a) Automatic door system using optical sensor and linear actuator
Problem Description
Implement logic for the automatic door open & close system in PLC using ladder diagram programming
language.
Problem Diagram
List of inputs
• Infrared sensor: I:1/0
• Closing limit switch: I:1/1
• Opening limit switch: I:1/2
List of outputs
• Opening motor: O: 2/0
• Closing motor: O: 2/1
Problem Solution
• In this system when someone enters the infrared sensing field, opening motor starts working
to open the door automatically till the door touches the door opening limit switch.
• If the door touches the opening limit switch for 8sec and no body enters the sensing
field/area, then closing motor starts to close the door automatically till the door touches the
closing limit switch.
• Stop the closing action immediately if someone enters the sensing field during the door
closing process.
List of inputs/outputs
PLC Ladder diagram for Automatic Door Control System
Program Description
Network 1: When infrared sensor is detected (I:1/0), door opening motor (O:2/0) will start. The door will be
open. When it touches the close limit switch (I:1/1), opening motor will be stop.
Network 2: When the door touches the opening limit switch (I:1/2), timer will be executed.
Network 3: After 10 seconds time closing motor (O:2/1) will start. When it touches the closing limit switch,
closing motor will turn OFF.

2. Vidya Vikas Educational Trust (R),
Vidya Vikas Polytechnic
27-128, Mysore - Bannur Road Alanahally, Alanahally Post, Mysuru, Karnataka 570028
Prepared by: Mr Thanmay J.S, H.O.D Mechanical Engineering VVETP, Mysore Page | 65
Develop PLC program for the following application
b) Automatic Elevator control
Problem Description
Design a PLC program to execute the elevator system Call buttons in a 4-floor apartment using Allen
Bradley PLC programming.
Problem Diagram
In the above picture, there are totally four floors. There are two user panels. One is inside the lift and other is
outside the lift. Limit switches are used to locate and stop the lift at each floor. Priority is given to the
Outside Call input.
Sl No I/O Value Used for
1 O:4/0 Motor Up movement control
2 O:4/1 Motor Down moment control
3 I:5 = 296 First / Ground Floor
4 I:5 = 212 Floor 2
5 I:5 = 128 Floor 3
6 I:5 = 46 Floor 4
7 I:1/11 Floor 4 Down Button
8 I:1/6 Floor 1 Up Button
9 I:1/8 Floor 3 Up Button
10 I:1/10 Floor 3 Down Button
11 I:1/7 Floor 2 Up Button
12 I:1/9 Floor 2 Down Button

3. Vidya Vikas Educational Trust (R),
Vidya Vikas Polytechnic
27-128, Mysore - Bannur Road Alanahally, Alanahally Post, Mysuru, Karnataka 570028
Prepared by: Mr Thanmay J.S, H.O.D Mechanical Engineering VVETP, Mysore Page | 66
Problem Solution / PLC Ladder Diagram