Design And Construction Of A Cable Tester

This project is titled the design and construction of a computer cable tester. It is designed to meet up with the safety and accuracy demand in flow of signal in computer cable.

It is design to detect If the cable carries the signal, this indicates that all the circuits are closed, meaning that electric current can move unimpeded through the wires, and that there are no short circuits, or unwanted connections, in the wire. A cable tester can identify if the wires are paired correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two wires that should not be connected. The tester can also tell whether the cable has the proper level of resistance.

This project was designed for confirming the continuity and correct wiring of computer leads which have 8 wires, but it can be used to check any lead with up to 8 wires by using appropriate connectors.

TABLE OF CONTENT

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

1.2      OBJECTIVE OF THE PROJECT

1.3      PURPOSE OF THE PROJECT

1.4      SIGNIFICANCE OF THE PROJECT

1.5      PROBLEM OF THE PROJECT

1.6      APPLICATION OF THE PROJECT

1.7      PROJECT ORGANISATION

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1      OVERVIEW OF THE STUDY

2.2     REVIEW OF DIFFERENT COMPUTER NETWORK TESTING

2.3      NETWORK CABLE INSTALLATION TOOLS

2.4      HOW TO USE CABLE TESTER

2.5      HOW USE NETWORK CABLE TEST

2.6      READING OF A CABLE TESTER

CHAPTER THREE

3.0     CONSTRUCTION

3.1     BLOCK DIAGRAM

3.2.0 SECTIONAL DESCRIPTION OF THE SYSTEM

3.2.1  POWER SUPPLY UNIT

3.2.2 TIMING UNIT

3.2.3 CONTROLLER UNIT

3.2.4 OUTPUT UNIT

3.3     CIRCUIT DIAGRAM

3.4    COMPONENTS USED

3.4     POWER SUPPLY UNIT

CHAPTER FOUR

4.0      CONSTRUCTION PROCEDURE AND TESTING

4.1      CASING AND PACKAGING

4.2      ASSEMBLING OF SECTIONS

4.3      TESTING OF SYSTEM OPERATION

4.4     COST ANALYSIS

CHAPTER FIVE

5.0      CONCLUSION

5.1      RECOMMENDATION

5.2      BIBLIOGRAPHY

CHAPTER ONE

1.0                                                        INTRODUCTION

A cable tester is an electronic device used to verify the electrical connections in a signal cable or other wired assembly. Basic cable testers are continuity testers that verify the existence of a conductive path between ends of the cable, and verify the correct wiring of connectors on the cable. More advanced cable testers can measure the signal transmission properties of the cable such as its resistance, signal attenuation, noise and interference. ^[1]

Generally a basic cable tester is a battery operated portable instrument with a source of electric current, one or more voltage indicators, and possibly a switching or scanning arrangement to check each of several conductors sequentially. A cable tester may also have a microcontroller and a display to automate the testing process and show the testing results, especially for multiple-conductor cables. A cable tester may be connected to both ends of the cable at once, or the indication and current source portions may be separated to allow injection of a test current at one end of a cable and detection of the results at the distant end. Both portions of such a tester will have connectors compatible with the application, for example, modular connectors for Ethernet local area network cables.

1.1                                            BACKGROUND OF THE STUDY

The idea behind the design and construction of this system is to make available or alternative means providing safety and accuracy demand in flow of signals in computer network. This goes a long way in helping to curb the problem frequently encountered as a result of open circuit and unwanted connection, in the wire.

When connected to an Ethernet cable, a cable tester tells if the cable is capable of carrying an Ethernet signal. If the cable carries the signal, this indicates that all the circuits are closed, meaning that electric current can move unimpeded through the wires, and that there are no short circuits, or unwanted connections, in the wire. cable testers vary in complexity and price, but a basic tester consists of a source of electrical current, a measuring device that shows if the cable is good, and a connection between the two, usually the cable itself.

Computer cable tester use Ethernet cables to allow computers in the network to “talk” to each other. An Ethernet cable has eight wires that are arranged in four pairs. For current to flow correctly, the wire pairs must be connected in the proper order.

A cable tester can identify if the wires are paired correctly. It can also show if there is a break in the insulation, a situation which allows crosstalk between two wires that should not be connected. The tester can also tell whether the cable has the proper level of resistance.

If a network isn’t working correctly, the problem is frequently user error or other problems. It will rarely be a faulty cable. A cable tester is more frequently used to tell whether a patch cable will work before it is connected. The cabling should first be examined visually to identify any obvious problems. If everything looks correct, a network cable testing device may then be used.

A cable tester is a simple apparatus that merely identifies whether current flows through the cable, or it may be a professional-level, complex device that gives additional information that helps identify the problem. Professional-level cable testers may not only tell if an open circuit exists, but may identify where the break is located. Some also identify the gauge of wire used and can generate their own signal to test for interference.

Basic cable testers can test for simple connectivity issues but may not identify other problems that cause the cable to malfunction. Cabling may not work when it is near a source of interference or if the cable is too long. Intermittent faults may develop that do not show up when the cable is tested. Sometimes the problem is not sustained long enough to show up on the tester.

1.2                                             OBJECTIVE OF THE PROJECT

A cable tester is used to verify that all of the intended connections exist and that there are no unintended connections in the cable being tested. When an intended connection is missing it is said to be “open”. When an unintended connection exists it is said to be a “short” (a short circuit). If a connection “goes to the wrong place” it is said to be “miswired” (the connection has two faults: it is open to the correct contact and shorted to an incorrect contact). However, the objective of the work is construct such device that does this work.

1.3                                              PURPOSE OF THE PROJECT

The purpose of this work is to have an accuracy test of wires that are paired. It can also show if there is a break in the insulation, a situation which allows crosstalk between two wires that should not be connected, which can also tell whether the cable has the proper level of resistance.

1.4                               SIGNIFICANCE OF PROJECT

A computer network consists of a group of computers and devices interconnected by communications channels, facilitating communications among multiple users. Computer networks make it possible for users to share multiple resources and access shared files. A hardwired network connection provides more secure and stable connections, transferring data directly. As with most computer connectivity, special tools are required to build a successful computer network.

1.4                           STATEMENT OF PROBLEM

Several studies have shown that the majority of network performance problems occur in or near the users’ desktop/laptop computer.  These problems include, but are not limited to, duplex mismatch conditions on Ethernet/FastEthernet links, incorrectly set TCP buffers in the user’s computer, or problems with the local network infrastructure.  The work is designed to quickly and easily identify a specific set of conditions that are known to impact network performance.  A multi-level series of plain language messages, suitable for novice users, and detailed test results, suitable for a network engineer, are generated and available to the user.  Finally, the test results may be easily emailed to the appropriate administrator to assist in the problem resolution phase.

Another problem is the inability of the testing personnel to use the instrument accurately. When these tester is not used accurately that means that an incorrect result is expected to be seen.

1.6                                                 SCOPE OF THE PROJECT

Cable tester is a battery operated portable instrument with a source of electric current, one or more voltage indicators, and possibly a switching or scanning arrangement to check each of several conductors sequentially. A network cable tester relies on the simple fact that network cables transmit data electronically. Because electricity requires a continuous physical connection, any breaks in the wiring inside the network cable prevent it from functioning. The other problem cables can face is that of cross-wiring, where some of the internal wires make the wrong connections, causing a short-circuit.

Most network cable testers can test two basic types of cable: coaxial and twisted pair. Coaxial cable, the kind used for cable TV, uses a single shielded conductor that runs down the center of the cable. Twisted pair relies on multiple pairs of wire wrapped together. Both kinds of twisted pair use similar connectors, but the one for an is larger than that for telephone. Coaxial cable normally uses the same kind of barrel connectors found in cable TV installations

1.7                                          APPLICATION OF THE PROJECT

1. In computer, it is used to perform computer signal continuity test.
2. In other electronics, it is used to Measure resistors, diodes, and check resistance thresholds with the CableEye PC Based cable tester. Also check wire harnesses.

1.8                          PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to a computer cable tester. In this chapter, the background, significance, objective limitation and problem of computer cable tester were discussed.

Chapter two is on literature review of a computer cable tester. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.