muhammad jawhar

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Lab
Student Name: Muhammad jawhar
Class: 4 Stage – Group:A1
Course Title: PLC Lab.
EXP NO: 3
EXP. Name: : Control of Conveyor System Using PLCs and
Sensors Objectives
College of Engineering
Salahaddin University of Erbil
Academic Year 2021-2022

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Abstract
A programmable Logic Controller (PLC) is a specialized computer used for the
control and operation of manufacturing process and machinery. It uses a
programmable memory to store instructions and execute functions including
on/off control, timing, counting, sequencing ,arithmetic, and data handling.
Programmable Logic Controllers (PLC) is used in almost every aspect of
industry to expand and enhance production. Where older automated systems
would use hundreds or thousands of electro mechanical relays, a single PLC can
be programmed as an efficient replacement. The functionality of the PLCs has
evolved over the years to include capabilities beyond typical relay control.
Sophisticated motion control, process control, distributive control systems, and
complex networking have now been added to the PLC’s Functions. Therefore,
PLCs provide many advantages over conventional relay type of control,
including increased reliability, more flexibility ,lower cost, communication
capability, faster response time and convenience to troubleshoot. The paper is
based on systematic conveyor controller programming by programmable logic
controller using software.
Introduction
The PLC is a microcontroller based device with input/output circuitry that monitors the status
of field connected sensor (inputs) and controls the attached (output) actuators (motor -starters,
Solenoids, Speed drives, Valves etc.) according to a user created logic program stored in the
memory. The main difference from other computers is that PLCs are armored for severe
condition (dust, moisture, heat, cold, etc) and have the facility for extensive input/output (I/O)
arrangements. These connect the PLC to sensors and actuators. PLCs read limit switches,
analog process variables (such as temperature and pressure), and the positions of complex
positioning systems. PLCs operate electric motors, pneumatic or hydraulic cylinders, magnetic
relays or solenoids, or analog outputs. The input/output arrangements may be built into a
simple PLC, or the PLC may have external I/O modules attached to a computer network that
plugs into the PLC. PLCs were invented as replacements for automated systems that would
use hundreds or thousands of relays, cam timers, and drum sequencers. Often, a single PLC
can be programmed to replace thousands of relays.
Programmable controllers were initially adopted by the automotive manufacturing industry,
where software revision replaced the re-wiring of hard wired control panels when production
models changed. Many of the earliest PLCs expressed all decision making logic in simple
ladder logic which appeared similar to electrical schematic diagrams.
Students are provided with a prebuilt conveyor simulator and a PC-based DAQ system
containing analog I/O and digital I/O capability. The objective is to design a control system
for the conveyor in order to meet a set of practical engineering requirements. This project is

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appropriate for a measurements and instrumentation course since it requires both hardware
and software design for interfacing the conveyor to a PC-based DAQ system for a
measurement and control application. Infrared proximity sensors are used for detecting the
position of an object on the conveyor. The time response characteristics for this system are
sufficiently slow such that control theory for dynamic control applications is not needed.
Upon the completion of this experiment, the student should be able to Objectives:
To learn how PLCs are used in automation systems.•
To learn how to use sensors in automation systems.•
Equipments Required:
Siemens S7 PLC unit, conveyor belt, proximity sensor (B11), photo sensor (B10), Metallic
cylinder, and plastic cylinder.
Theoretical background:
The single track conveyer belt is for connecting two operating stations or units in order to
assemble flexible manufacturing facilities .using automatic handling equipment it can be
combined with any functional unit or operating module. The conveyor belt consists of a
singletrack belt that is equipped with an electrical drive and includes an optical sensor for
detecting when work pieces reach the end of the conveyor and an inductive sensor in the
middle of the belt. The mechanical design of the belt employs metal profiles that allow for
additional installation options (sensors, cylinders) to easily be retrofitted.

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Questions:
1-A proximity sensor is a sensor able to detect the presence of nearby objects without any
physical contact.
A proximity sensor often emits an electromagnetic field or a beam of electromagnetic
radiation (infrared, for instance), and looks for changes in the field or return signal. The object
being sensed is often referred to as the proximity sensor's target. Different proximity sensor
targets demand different sensors. For example, a capacitive proximity sensor or photoelectric
sensor might be suitable for a plastic target; an inductive proximity sensor always requires a
metal target.
Proximity sensors can have a high reliability and long functional life because of the absence of
mechanical parts and lack of physical contact between the sensor and the sensed object.
Proximity sensors are also used in machine vibration monitoring to measure the variation in
distance between a shaft and its support bearing. This is common in large
steam turbines, compressors, and motors that use sleeve-type bearings.
A proximity sensor adjusted to a very short range is often used as a touch switch.
2-the motor will not turn run because key 1 is used to move CCW and key 2 is used to move
CW