Data Communication & Networking in Manufacturing System

Data Communication & Networking in Manufacturing System


Nanang Ali SutisnaMaster Eng. in Computer Integrated Manufacture

Senior PLM Consultant, IBM IndonesiaSenior Manager, Product Development

Multistrada Arah Sarana

Chapter 1Introduction to

Manufacturing System

Chapter 1Introduction to

Manufacturing System



3

Suppliers/Vendor

• Supplier chain• Purchasing

Customer Support

• Pre/Post Sales Support

ISO ApprovalReview,

Design Release

• Digital Design Review• View & Markup• Recognition• Audit

Account / Finance

• Costing• Define

incentive program

Sales &Marketing

• Quick Response• Marketing Proposal• Easy to quote• Presentation• Product Launch

HumanResource

• Training• Corporate Communication• Staff Development• Virtual Learning

EngineeringDesign

• CAD/CAM• CAE / FEA• Prototyping

IT Research & Development

• Technology• Methodology• Integrating

Distribution

• Fulfillment• Delivery

Manufacturing/AssemblyShop floor

• Product Assembly/Disassembly Sequencing

• Robotic/Work Cell Animation• Digital Factory

Factory Manager/ Production

Planner

• Actual vs. schedule• Scheduling• Work-to-lists• Route cards

Quality Control

• Defect Analysis• Quality Control

e-Manufacturing

e-Manufacturing Systemse-Manufacturing Systems

BOM

P L M

PLM is a set of capabilities that enables an enterprise to effectivelyeffectively and efficiently efficiently innovate and manage its products and related services throughout the entirethe entire business lifecyclebusiness lifecycle, from conception through recycling or disposal.

P L M

ProductEngineering

Lifecycle Management & Decision Support

Manufacturing

Engineering

Product Lifecycle Management

Production SystemProduction System

The production system is the collection of people, equipment, and procedures organized to accomplish the manufacturing operations of a company (or other organization).

Production SystemProduction System

Manufacturing Support Systems

Facilities: - Factory - Equipment

Pro

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on

Syste

m

Manufacturing support SystemsThis is the set of procedures used by the company to manage production and to solve the technical and logistics problems encountered in ordering materials, moving work through the factory and ensuring that products meet quality standards. Product design and certain business functions are included among the manufacturing support systems.

Facilities The facilities of the production system consist of the factory, the equipment in the factory, and the way the equipment is organized.

8

Production System FacilitiesProduction System Facilities

• The facilities in the production system are the factory, production machines and tooling, material handling equipment, inspection equipment, and the computer systems that control the manufacturing operations.

9

Production System FacilitiesProduction System Facilities

• Facilities also include the plant layout, which is the way the equipment is physically arranged in the factory. The equipment is usually organized into logical groupings (equipment arrangements) and the workers who operate them as the manufacturing systems in the factory.

10

Manufacturing SystemsManufacturing Systems

• Manufacturing systems can be individual work cells, consisting of a single production machine and worker assigned to that machine.

• We more commonly think of manufacturing systems as groups of machines and workers, for example, a production line.

The manufacturing systems come in direct physical contact with the parts and/or assemblies being made. They "touch" the product.

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Manufacturing TypesManufacturing Types

One of the most important factors that determine the type of manufacturing is the type of products that are made. •Discrete products manufacturing: including automotive, aircraft, appliances, computers, machinery, etc.•Process manufacturing: products that are in liquid or bulk form, such as chemicals, pharmaceuticals, petroleum, basic metals, food, beverage, electric power generation, etc

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Production QuantityProduction Quantity

In discrete products manufacturing, the quantity produced by a factory has a very significant influence on its facilities and the way manufacturing is organized.

The annual part or product quantities produced in a given factory can be classified into three ranges:

1.Low production: Quantities in the range of 1 to 100 units per year2.Medium production: Quantities in the range of 100 to 10,000 units per year3.High production: Production quantities are 10,000 to millions of units per year

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Product Variety vs Production QuantityProduct Variety vs Production Quantity

14

100 10,000 1,000,000

Low Prod.

Medium

High Prod.

Pro

du

ct

vari

ety

Production quantity

Facility and LayoutFacility and Layout

15

100 10,000 1,000,000

Pro

du

ct

vari

ety

Production quantity

Fixed PositionLayout Process

Layout

CellularLayout

ProductLayout

Manufacturing Support SystemManufacturing Support System

Business Function - sales and marketing, order entry, cost accounting, customer billing

Product Design - research and development, design engineering, prototype shop

Manufacturing Planning - process planning, production planning, MRP,

capacity planning

Manufacturing Control -shop floor control,

inventory control, quality control

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Chapter 2Digital Manufacturing

Chapter 2Digital Manufacturing



Today’s Business RequirementsDrive Change & Determine Real-time Enterprise Needs

Globalization Rapid Product Innovation Process Innovation Collaboration Synchronization Lean Continuous Improvement Compliance Risk Management Performance Flexibility Pull-based Production Etc.

Evolution of the Design/Build Process

90s

Integration of Product Design and Production Process Design

80s 2000 2006…..

3D

Digital Mockup

Digital Manufacturing

KnowledgeCapture

2D

Tech

nolo

gic

al A

dvan

ce

Design & Validation of Manufacturing Processes

“Digital Manufacturing represents an integrated suite of PLM tools that supports manufacturing process design, tool design, plant layout, and visualization through powerful virtual simulation tools that allow the manufacturing engineer to validate and optimize the manufacturing processes. “

What is Digital Manufacturing?

R&D Design Engr

Process Planning

Work Flow, Mfg

Processes

Materials & Product Research

Product Design

Mfg Engr Industrial Engr

Design, Produce

Tools, Jigs, Fixtures, & Automated

Systems

Controls/Tool Engr

Obtain, Operate, Control, & Maintain Equipment & Automated Systems to Manufacture Products

Factory Operations/ Production Systems

Collaborative PDM

CAM/NC

Product Domain Production Domain

Scheduling

Resource Mgmt

Mfg Intelligence

Q/A

Visibility

Supply Chain

Specs, E-BOM, M-BOMAutomated Assembly

Processes

Org

Function (Systems)

Engineering

Operations

Product Lifecycle: Design/Build/Automate/Maintain

PLM Solutions: Interoperability & Collaboration

Operations Mgmt

Where Does Digital Manufacturing Fit?

Digital Mfg/Production Process Design, Virtual Factory Simulation

CAD/CAE (Digital Def.)

Manufacturing Planning• Define High-Level Manufacturing Processes• Process Planning (Assembly & Installation) • Define Work Instructions & Work Flow

Detailed Process Design & Analysis• Detailed Resource Modeling & Simulation• Process Definition and Validation• 3-D Factory Layout • Equipment, Tool & Fixture Simulation• Ergonomic Simulation

Validation & Virtual Commissioning• Control Logic Validation• Kinematic (Robotic) Validation• Quality Assurance/Process Improvement Validation• Sensor/Metrology Placement Validation• Virtual Commissioning/Validation of Automation Systems• Knowing that the Production System Works Prior to

Launch: Priceless.

What Does Digital Manufacturing Do?What Does Digital Manufacturing Do?

Digital Manufacturing Redefines Concurrent Engineering Digital Manufacturing Redefines Concurrent Engineering

• Product Authoring (CAD) tools are employed to define “What" is to be built.

• Manufacturing Process Design tools are used to define “How" it is to be built.

• Integration of Product & Process Design directly supports the concept of Concurrent Engineering

Digital Manufacturing facilitates the Holistic view of Product and Process Design as integral components of the overall product life cycle

PLM/Digital Manufacturing are Process-Centric

Managing the Manufacturing Process

Integration of Product Design with Mfg Processes allows Production Management & Execution Applications to be Integrated with the PLM Solution Set

Manufacturing Process Design coupled with Digital Mfg Simulation Integrates the Definitions of the Product, Processes, Factory, and Resources into a Comprehensive and Consistent Manufacturing Solution

Manufacturing Process Mgmt (MPM), as a Component of the PLM Solution Set Generates traditional Operations Management Functions such as Process Planning, Work Instructions, and Operations & Quality Assurance Records Scheduling, Workflow, Resource Mgmt, WIP, and Visibility

Design/Engineering Infrastructure

Global Manufacturing Operations

Enterprise InfrastructureOperations Infrastructure

= Manufacturing Node = Design Node

Operations Management Definition:

Operations Management is the management of the people, business processes, technology and capital assets involved in:

• Procuring and receiving raw materials and components- Especially as it relates to obtaining, storing, and moving

necessary materials/components in a timely manner and of suitable quality to support efficient production

• Implementing product designs, specifications, formulations, or recipes by manufacturing products- Including manufacturing process planning and validation

• Distributing these products to customers- Especially as it relates to sequencing and in-house logistics

• And for some products, supporting them through their End-of-Life

Let Business Requirements Drive Technology Solutions

Industry Classic MES New RequirementsSemiconductor Complex Routing, Resource

Allocation, Quality, WIP Tracking, etc.

Visibility, Analytics/Decision Support, Outsourced Manufacturing, Business System Synchronization, KPIs, Performance, Change Mgmt, Security, Electronic Manufacturing History etc.

Pharmaceutical Compliance, Quality (Direct and Enforce Production), Electronic Batch Records, Electronic Signature, etc.

Visibility, Analytics/Decision Support, Outsourced Manufacturing, Business System Synchronization, Performance, Change Mgmt, Security, Electronic Manufacturing History etc

Continuous Process

Collection of Apps: Optimization, Historian, Advanced Process Control, etc.

Visibility, Analytics/Decision Support, Outsourced Manufacturing, Business System Synchronization, Performance, Change Mgmt, Security, Electronic Manufacturing History, etc

A&D (Complex Discrete)

CAPP, Quality, Resource Allocation (Operators, Workstations, Tooling, etc.) WIP Tracking, Traceability, Work Instructions, NCR Resolution, etc.

Visibility, Analytics/Decision Support, Outsourced Manufacturing, Supplier Quality Mgmt, Change Management, Security, Electronic Manufacturing History, etc

Automotive Supplier

Quality, Resource Allocation (Operators, Workstations, Tooling, etc.) Work Instructions, Just-in Sequence Manufacturing/ Packing/ Shipping, Error-proof Packout and Labeling, etc.

Visibility, Analytics/Decision Support, Orchestrate Inventory Replenishment by Operation, Traceability and Recall Management, Business System Synchronization, Performance, Change Mgmt, Security, Electronic Manufacturing History, etc

Automotive OEM Visual Alarms, Stack Lights, and Marquees, Line Control & Broadcasting, Supplier Component Sequencing, etc.

Visibility, Outsourced Manufacturing, Global Manufacturing, Business System Synchronization, Performance, Change Mgmt, Security, Electronic Manufacturing History, Traceability and Genealogy, etc

Today’s Dynamic, Demanding Environment Places a Premium on Information and Synchronization

Business

Customers

FINERP

EAM

Equipment & Automation

HR

WMS

T&A

Suppliers

Lean/CI

TMS

HMI

MISched

Production

etc.

CAM

QualityDesignMPM

CRM

CAD

Operations Infrastructure

Enterprise Infrastructure

SCM

Support

Gen 3(Integrated Apps, Infrastructure, &

Connectivity)

MES Gen 2

MES

MES Gen 1(Standalone, Industry-Specific Application)

(Collection of Applications)

Gen 4(SOA)

Operations Management

CMM Applications MapLet’s Get on the Same Page re: MES and OM

Production Mgmt Systems are Extension of PLM Production Mgmt Systems are Extension of PLM

Manufacturing Processes

Product Lifecycle Processes

Design Build Automate Maintain

Create Processes

PlanProcesses

Simulate & Validate Processes

ExecuteProcesses

Digital Manufacturing Solutions + MES

As – Built RecordsEngineering DesignValidate

Tailored Work Package

• Process Configuration

• Work Instructions

• Work Flow Routing

• Operations Scheduling

• Shop Floor Requirements

• Data Exchange

• Performance Analysis

• Quality Assurance

• Labor/Parts/Tooling

PLM Integrated with Shop Floor ExecutionPLM Integrated with Shop Floor Execution

PLM

Process Creation

Product Design

• E-BOM

• M-BOM

• Bill of Process

• Product Config.

Maintenance & Support

“As Designed” Product Data

Production Mgmt

Shop Floor Execution

(MES)

“As Built” Records

“As Designed” Process Data

ERP

CAD

Product Design

Process Models,3D Simulations, Work Order

Instructions

Process Execution

Shop Floor Execution (MES)

Quality Assurance

Unit Data & Work History

Data Vault

3D ModelsE-BOM Process

Modeling

Digital Manufacturing/MPM

Process Simulation & Validation

Process Planning

InventoryMgmt

Work OrdersRelease & Status

Financials

Invoicing Shipping

Labor Reporting

ReceivingParts Purchasing

ERP

Production Scheduling

Work Order Release

Work Order Status

Material / Parts

Job Sign On/Off

Digital Mfg + Shop Floor Execution = Validation of As-Built to As-Designed Digital Mfg + Shop Floor Execution = Validation of As-Built to As-Designed

Closing the Loop From As-Built Records To As-Designed

Master Routings, M-BOM

E-BOM

PDM

Product Data Management

Collaborative

Merging Virtual Simulation and Automation

Simulation to Control: Making the Final Step from Virtual to Real

Digital Validation Produces Real Control

Execution

Collaborative Environment for Control Design & Digital

Validation

Real OperationsReal OperationsReal OperationsReal OperationsVirtual SimulationVirtual SimulationVirtual SimulationVirtual Simulation

Production SystemProduction SystemProduction SystemProduction SystemProcess DesignProcess DesignProcess DesignProcess Design

Interoperable Virtual to Real-World Environment for Manufacturing and Control Engineering

DE

SIG

NV

ALI

DA

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PHYSICALVIRTUAL

Target PLC or Controller Platform

Developed with Automation providers

Code Generator

Control Design

Mfg Process Modeling

Production Simulation

Validate Control

PLC/Controller HMI

Post-Processed Machine Logic

OPC Client/Server

3D Mechanical Design

Control Engineering

(Design)

Line Building & Installation

Production Startup

Current workflow….

Workflow…with Virtual Automation

3D Mechanical Design

ControlEngineering

LineBuilding

Control Eng.

Production Startup

Validation & Virtual Commissioning

Merging Virtual Design and Automation Shortens Time to Launch

Control Engineering (Commissioning)

Effective & Efficient Use of Digital Mfg (DM) Tools: Guidelines for Users

Effective & Efficient Use of Digital Mfg (DM) Tools: Guidelines for Users

Integrate Use of DM Tools into the Manufacturing Design Process

• Set and Implement guidelines for application of DM technology

• Provide DM training for Mfg Engineering Discipline & Resources Emphasize Re-use

• Re-use dependent on a strategy common process design Common components is a key enabler Establish a library of virtual production devices & equipment

• A modular approach is key for efficiently building virtual models Start with basic virtual devices building blocks Build virtual production systems by combining virtual devices

Integrate DM Tools into the Information & Control Architecture

• Virtual models can be developed & maintained by multiple engineering disciplines (Manufacturing, Tooling, Controls)

• Use latest Production Process data for Virtual Simulations

Digital Manufacturing Landscape

Manufacturers are focusing on Optimization of Production Processes

Reducing Time to Product Launch and Cost of Commissioning Production Systems

Today’s PLM Suppliers now offer robust Digital Manufacturing Solutions

Large Manufacturers Are Adopting End-to-End PLM Strategies, including Digital Manufacturing • A&D: Boeing, Lockheed-Martin, Northup-Grumman

• Automotive: GM, Chrysler, Ford, Toyota, Nissan, BMW, Mercedes Benz

• Heavy Equipment: Caterpillar, John Deere, Cummins

Companies are Transforming how they Define their Manufacturing Processes

Key Benefits of Digital Manufacturing

Integration of Product Design and Manufacturing Processes Reduce Cost and Development Time for Process Design Shorten Time-to-Launch for New Product Introduction with Faster

Ramp-up for Production Systems Provide Manufacturability by Simulating Manufacturing Operations

before the Start of Production Increase Quality by Validating Production Process Design Reduce and/or eliminate Prototypes and Physical Mockups with

Virtual Simulations Improve Collaboration with Suppliers by Providing Early Access to

Design, Production Process, and Resource information Improve Concurrent Design Methods by Linking Product Design to

Manufacturing & Controls Engineering Validate Manufacturing Processes, Production Systems, and

operational resources through Virtual Commissioning prior to physical implementation

Chapter 3Computer System

Fundamental

Chapter 3Computer System

Fundamental



The Primary Components Of A Computer The Primary Components Of A Computer

Input devices. Central Processing

Unit (containing the control unit and the arithmetic/logic unit).

Memory. Output devices. Storage devices.

Central processing unitCentral processing unit

A central processing unit (CPU), or sometimes just called processor, is a description of a class of logic machines that can execute computer programs.

This broad definition can easily be applied to many early computers that existed long before the term "CPU" ever came into widespread usage. However, the term itself and its initialism have been in use in the computer industry at least since the early 1960s (Weik 1961).

The form, design and implementation of CPUs have changed dramatically since the earliest examples, but their fundamental operation has remained much the same.

Central processing unitCentral processing unit

Early CPUs were custom-designed as a part of a larger, usually one-of-a-kind, computer. However, this costly method of designing custom CPUs for a particular application has largely given way to the development of mass-produced processors that are suited for one or many purposes.

This standardization trend generally began in the era of discrete transistor mainframes and minicomputers and has rapidly accelerated with the popularization of the integrated circuit (IC).

The IC has allowed increasingly complex CPUs to be designed and manufactured in very small spaces (on the order of millimeters). Both the miniaturization and standardization of CPUs have increased the presence of these digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to cell phones to children's toys.

EDVAC, one of the first electronic stored program computers.

Early ComputersEarly Computers

ENIAC (Electronic Numerical Integrator And Computer), was the first general-purpose electronic computer. ENIAC was designed and built to calculate artillery firing tables for the U.S. Army's Ballistic Research Laboratory.

transistor evolutiontransistor evolution

later packaged in small IC’s

eventually came VLSIVery Large Scale Integrationmillions of transistors per chip

first transistor made from materials including a paper clip and a razor blade

the integrated circuit (IC)the integrated circuit (IC)

invented separately by 2 people ~1958• Jack Kilby at Texas Instruments

• Robert Noyce at Fairchild Semiconductor (1958-59)

1974• Intel introduces the 8080 processor

• one of the first “single-chip” microprocessors

MicroprocessorMicroprocessor

Processors were for a long period constructed out of small and medium-scale ICs containing the equivalent of a few to a few hundred transistors.

The integration of the whole CPU onto a single VLSI chip therefore greatly reduced the cost of processing capacity.

From their humble beginnings, continued increases in microprocessor capacity has rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessor as processing element in everything from the smallest embedded systems and handheld devices to the largest mainframes and super computers.

Three projects arguably delivered a complete microprocessor at about the same time, namely Intel's 4004, the Texas Instruments (TI) TMS 1000, and Garrett AiResearch's Central Air Data Computer (CADC).

The 4004 with cover removed (left) and as actually used (right).


ArchitecturesArchitectures

8-bit designs 16-bit designs 32-bit designs 64-bit designs in personal computers Multicore designs RISC Special-purpose designs

• microcontrollers, digital signal processors (DSP) and graphics processing units (GPU).

65xx • MOS Technology 6502 • Western Design Center 65xx

ARM family Altera Nios, Nios II Atmel AVR architecture (purely microcontrollers) EISC RCA 1802 (aka RCA COSMAC, CDP1802) DEC Alpha Intel

• 4004, 4040 • 8080, 8085 • 8048, 8051 • iAPX 432 • i860, i960 • Itanium

LatticeMico32 M32R architecture MIPS architecture Motorola

• Motorola 6800 • Motorola 6809 • Motorola 68000 family, ColdFire • MotoG4, G5


NSC 320xx OpenCores OpenRISC architecture PA-RISC family National Semiconductor SC/MP ("scamp") Signetics 2650 SPARC SuperH family Transmeta Crusoe, Efficeon (VLIW architectures, IA-32 32-bit Intel

x86 emulator) INMOS Transputer x86 architecture

• Intel 8086, 8088, 80186, 80188 (16-bit real mode-only x86 architecture)

• Intel 80286 (16-bit real mode and protected mode x86 architecture)

• IA-32 32-bit x86 architecture

• x86-64 64-bit x86 architecture

and others


Microprocessor SystemMicroprocessor System

A microprocessor incorporates most or all of the functions of a central processing unit (CPU) on a single integrated circuit (IC).

The first microprocessors emerged in the early 1970s and were used for electronic calculators, using BCD arithmetics on 4-bit words.

Other embedded uses of 4 and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc, followed rather quickly.

Affordable 8-bit microprocessors with 16-bit addressing also led to the first general purpose microcomputers in the mid-1970s.


Die of an Intel 80486DX2 microprocessor (actual size: 12×6.75 mm) in its packaging

Microprocessor chips are the basic building blocks for nearly all of the "intelligent" control systems found in a modern manufacturing organization. Smaller systems have a single microprocessor chip acting as the entire Central ProcessingUnit (CPU). This is typical of Personal Computers, Workstations and small industrial controllers. Larger computer-based systems use microprocessors as building blocks for entire boards, which may themselves act as CPUs or closed loop controllers.

Regardless of the architecture of intelligent systems, the principles by which communication occurs between a microprocessor chip and other associated semiconductor devices are essentially the same. We shall examine communicationsin a simple, single processor system to illustrate the key features involved.



The microprocessor chip can be envisaged as a machine that generates a number of internal voltage levels which together define the internal "state" of that machine. The internal state of the microprocessor changes at a rate determined by an external clock chip. The internal "state" voltage levels are decoded (by appropriatecircuits) in order to:

• move data into or out of the microprocessor• manipulate data within the microprocessor (add, subtract, etc.)• move data from one internal storage location (register) to

another.

Each cycle (tick) of the clock causes the microprocessor to jump from one internal state to another. The "next state" of the microprocessor is determined by a logical combination of its current internal state, together with the condition of all the various input lines connected to it. This

Microprocessor System


The architecture of semiconductor devices such as microprocessors, memory chips, etc., is based upon the use of only two voltages - low (false / off) or high (true /on). This is referred to as a "binary" or "base 2" system. Typically a voltage in the order of five volts is treated as high, and voltages of approximately zero are treated as low. The actual values depend upon the semiconductor technology used to fabricate a particular set of chips.

At any one point within a microprocessor chip, only the numbers 0 or 1 can be represented electronically at any instant in time. Similarly, the microprocessor's links to its outside world, the conducting, bus lines can also only have either a high or lowvoltage at any instant. Multiple conductors are therefore needed on a bus in order for the microprocessor to handle realistic numbers. A system with "n" conductors can therefore directly handle numbers ranging from:

0 to (2n - 1)


From Figure 1.3 at any time "T", we have the following, "binary" number:1 0 1 1 1 1 0 1

At any instant in time (neglecting transition periods), each point in a digitalcircuit represents one binary digit. This is abbreviated to the word "bit".


Number Systems: DecimalNumber Systems: Decimal

The decimal (or base 10) number system, the following is a count sequence:

0 1 2 3 4 5 6 7 8 910 11 12 13 14 15 16 17 18 1920 21 22 23 24 25 26 27 28 29..90 91 92 93 94 95 96 97 98 99100 101 102 103 104 105 106 107 108 109

the decimal number 721 actually represents the following:

(7 x 102) + (2 x 101) + (1 x 100)

The “Octal" number system arises regularly. A count sequence in base 8 takes on the following form:

0 1 2 3 4 5 6 710 11 12 13 14 15 16 1770 71 72 73 74 75 76 77100 101 102 103 104 105 106 107

The octal number 721 actually represents the following:(7 x 82) + (2 x 81) + (1 x 80)

which is equal to decimal 465 and not decimal 721.

When working with a range of different number systems, it is common practice to subscript numbers with the base of the number system involved. For example, we can validly write the following expression:

7218 = 46510

Number Systems: Octal

The “Hexadecimal” number system or base 16. Since we do not have enough of the ordinary numerals (0..9) to represent 16 different numbers with a single symbol, we "borrow" the first six letters of the alphabet (A..F). A count sequence in base 16 then takes on the following form:

0 1 2 3 4 5 6 7 8 9 A B C D E F10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F..F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF100 101 102 103 104 105 106 107 108 109 10A 10B 10C 10D 10E 10F

To similarly convert the hexadecimal number 721 to decimal:

72116 = (7 x 162) + (2 x 161) + (1 x 160) = 182510

Number Systems: Hexadecimal

Number Systems: Binary

Finally we move on to the number system most closely related to the architecture of computer systems themselves, the binary number system, in which we can only count from 0 to 1 before performing a "shift" operation. The following is a base 2 count sequence:

0 110 11100 101 110 1111000 1001 1010 1011 1100 1101 1110 1111

If we look again at Figure 1.3, we can now see that the number represented by the voltage waveforms at time "T" is:

101111012 =

(1x27) + (0x26) + (1x25) + (1x24) + (1x23) + (1x22) + (0x21) + (1x20)

= 18910

Number Systems: BCD

In order to establish an analogous, direct relationship between binary and decimal, another number representation is also in use. This is referred to as the Binary Coded Decimal or BCD system.

In the BCD system, each decimal digit is represented in binary by four bits.

For example, the BCD equivalent of the number 721 is given by:

0111 0010 0001

Number Systems

Two specifications for the bit patterns representing alpha-numeric characters are in common use. These are the 7 bit ASCII (American Standard Code for Information Interchange) and the 8 bit EBCDIC (Extended Binary Coded Decimal Interchange Code) systems.

Representation of Alpha Numeric



Chapter 4Data Communication

Fundamental

Chapter 4Data Communication

Fundamental



What is data communication?What is data communication?

Not to be confused with telecommunication• Any process that permits the passage from a sender to one

or more receivers of information of any nature, delivered in any easy to use form by any electromagnetic system.

Data communication• Defined as a subset of telecommunication involving the

transmission of data to and from computers and components of computer systems.• More specifically data communication is transmitted via

mediums such as wires, coaxial cables, fiber optics, or radiated electromagnetic waves such as broadcast radio, infrared light, microwaves, and satellites.

History of TelecommunicationsHistory of Telecommunications

Invention of telegraph Samuel Morse – 1837 Invention of telephone- Alexander Graham

Bell – 1876 Development of wireless By ??? – 1896 Concept of universal access and growth of

AT&T Divestiture of AT&T—what year??

History of Telecommunications Continued….History of Telecommunications Continued….

Telecommunications Act of 1996Three main developments that led to

the growth of data communications systems:• Large-scale integration of circuits reduced the

cost and size of terminals and comm equipment

• Developments of software systems made establishment of communication networks easy

• Competition among providers of transmission facilities reduced the cost of data circuits

History of Data CommunicationHistory of Data Communication

Transistor developed by Bell Labs 1947Hush-a-Phone CaseCarterphone caseMCI and Long DistanceCreation of networks (LAN’s and

WAN’s)Data Link ProtocolsMicrocomputers

History of the InternetHistory of the Internet

1836 -- Telegraph. Cooke and Wheatstone patent it. Why is this relevant? •Revolutionized human telecommunications. •Morse Code a series of dots and dashes used to communicate between humans. This is not a million miles away from how computers communicate via (binary 0/1) data today. Although it is much slower!!

1858-1866 -- Transatlantic cable. Allowed direct instantaneous communication across the Atlantic. Why is this relevant? •Today, cables connect all continents and are still a main hub of telecommunications.

1876 -- Telephone. Alexander Graham Bell Exhibits. Why is this relevant? •Telephones exchanges provide the backbone of Internet connections today. •Modems provide Digital to Audio conversions to allow computers to connect over the telephone network.

1957 -- USSR launches Sputnik, first artificial earth satellite. Why is this relevant? •The start of global telecommunications. Satellites play an important role in transmitting all sorts of data today. •In response, US forms the Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD) to establish US lead in science and technology applicable to the military.

1962 - 1968 -- Packet-switching (PS) networks developed Why is this relevant? •As we will see later the Internet relies on packets to transfer data. •The origin is military : for utmost security in transferring information of networks (no single outage point). •Data is split into tiny packets that may take different routes to a destination. •Hard to eavesdrop on messages. •More than one route available -- if one route goes down another may be followed. Networks can withstand large scale destruction (Nuclear attack - This was the time of the Cold War).

1969 -- Birth of Internet ARPANET commissioned by DoD for research into networking. Why is this relevant? •First node at UCLA (Los Angeles) closely followed by nodes at Stanford Research Institute, UCSB (Santa Barbara) and U of Utah (4 Nodes).

1971 -- People communicate over a network •15 nodes (23 hosts) on ARPANET. •E-mail invented -- a program to send messages across a distributed network. Why is this relevant?

E-mail is still the main way of inter-person communication on the Internet today. You will make extensive use of E-mail for the rest of your life.

1972 -- Computers can connect more freely and easily •First public demonstration of ARPANET between 40 machines. •Internetworking Working Group (INWG) created to address need for establishing agreed upon protocols. Why is this relevant?

Telnet specification Telnet is still a relevant means of inter-machine connection today.

1973-- Global Networking becomes a reality •First international connections to the ARPANET: University College of London (England) and Royal Radar Establishment (Norway) •Ethernet outlined -- this how local networks are basically connected today. •Internet ideas started. •Gateway architecture sketched on back of envelope in hotel lobby in San Francisco. Gateways define how large networks (maybe of different architecture) can be connected together. •File Transfer protocol specified -- how computers send and receive data.

1974 -- Packets become mode of transfer •Transmission Control Program (TCP) specified. Packet network Intercommunication -- the basis of Internet Communication. •Telnet, a commercial version of ARPANET, opened -- the first public packet data service.

1976 -- Networking comes to many •Queen Elizabeth sends out an e-mail. •UUCP (Unix-to-Unix CoPy) developed at AT&T Bell Labs and distributed with UNIX. Why is this relevant?

UNIX was and still is the main operating system used by universities and research establishments. These machines could now ``talk'' over a network. Networking exposed to many users worldwide.

1977 -- E-mail takes off, Internet becomes a reality •Number of hosts breaks 100. •THEORYNET provides electronic mail to over 100 researchers in computer science (using a locally developed E-mail system and TELNET for access to server). •Mail specification •First demonstration of ARPANET/Packet Radio Net/SATNET operation of Internet protocols over gateways.

1979 -- News Groups born •Computer Science Department research computer network established in USA. •USENET established using UUCP. Why is this relevant?

USENET still thrives today. A collection of discussions groups, news groups. 3 news groups established by the end of the year Almost any topic now has a discussion group.

•First MUD (Multiuser Dungeon) -- interactive multiuser sites. Interactive adventure games, board games, rich and detailed databases. •ARPA establishes the Internet Configuration Control Board (ICCB). •Packet Radio Network (PRNET) experiment starts with ARPA funding. Most communications take place between mobile vans.

1981 -- Things start to come together •BITNET, the "Because It's Time NETwork" Started as a cooperative network at the City University of New York, with the first connection to Yale

Provides electronic mail and listserv servers to distribute information, as well as file transfers •CSNET (Computer Science NETwork) established to provide networking services (specially E-mail) to university scientists with no access to ARPANET. CSNET later becomes known as the Computer and Science Network.

1982 -- TCP/IP defines future communication •DCA and ARPA establishes the Transmission Control Protocol (TCP) and Internet Protocol (IP), as the protocol suite, commonly known as TCP/IP, for ARPANET. Why is this relevant?

Leads to one of the first definitions of an internet as a connected set of networks, specifically those using TCP/IP, and Internet as connected TCP/IP internets.

•EUnet (European UNIX Network) is created by EUUG to provide E-mail and USENET services. Original connections between the Netherlands, Denmark, Sweden, and UK External Gateway Protocol specification -- EGP is used for gateways between (different architecture) networks.

1983 -- Internet gets bigger •Name server developed. Why is this relevant?

Large number of nodes. Hard to remember exact paths Use meaningful names instead.

•Desktop workstations come into being. Why is this relevant?

Many with Berkeley UNIX which includes IP networking software. Need switches from having a single, large time sharing computer connected to Internet per site, to connection of an entire local network.

•Internet Activities Board (IAB) established, replacing ICCB •Berkeley releases new version of UNIX 4.2BSD incorporating TCP/IP. •EARN (European Academic and Research Network) established on similar lines to BITNET

1984 -- Growth of Internet Continues •Number of hosts breaks 1,000. •Domain Name Server (DNS) introduced.

instead of 123.456.789.10 it is easier to remember something like

www.myuniversity.mydept.mynetwork.mycountry ( e.g. www.cs.cf.ac.uk). •JANET (Joint Academic Network) established in the UK •Moderated newsgroups introduced on USENET.

1986 -- Power of Internet Realised •5, 000 Hosts. 241 News groups. •NSFNET created (backbone speed of 56 Kbps) •NSF establishes 5 super-computing centers to provide high-computing power for all -- This allows an explosion of connections, especially from universities. •Network News Transfer Protocol (NNTP) designed to enhance Usenet news performance over TCP/IP.

1987 -- Commercialization of Internet Born •Number of hosts 28,000. •UUNET is founded with Usenix funds to provide commercial UUCP and Usenet access.

1988 •2 November - Internet worm burrows through the Net, affecting ~6,000 of the 60,000 hosts on the Internet •CERT (Computer Emergency Response Team) formed by DARPA in response to the needs exhibited during the Morris worm incident. The worm is the only advisory issued this year. •NSFNET backbone upgraded to T1 (1.544 Mbps) •Internet Relay Chat (IRC) developed

1989 -- Large growth in Internet •Number of hosts breaks 100,000 •First relays between a commercial electronic mail carrier and the Internet •Internet Engineering Task Force (IETF) and Internet Research Task Force (IRTF) comes into existence under the IAB

1990 -- Expansion of Internet continues • Electronic Frontier Foundation (EFF) is founded by Mitch Kapor •300,000 Hosts. 1,000 News groups •ARPANET ceases to exist •Archie released files can be searched and retrieved (FTP) by name. •The World comes on-line (world.std.com), becoming the first commercial provider of Internet dial-up access.

1991 -- Modernization Begins •Commercial Internet eXchange (CIX) Association, Inc. formed after NSF lifts restrictions on the commercial use of the Net. •PGP (Pretty Good Privacy) released by Philip Zimmerman •US High Performance Computing Act (Gore 1) establishes the National Research and Education Network (NREN) •Wide Area Information Servers (WAIS) Why is relevant?

Provides a mechanism for indexing and accessing information on the Internet. Large bodies of knowledge available: E-mail messages, text, electronic books, Usenet articles, computer code, image, graphics, sound files, databases etc.. These form the basis of the index of information we see on WWW today. Powerful search techniques implemented. Keyword search.

1991 (cont) -- Friendly User Interface to WWW established •Gopher released by Paul Lindner and Mark P. McCahill from the U of Minnesota. Why is relevant?

Text based, menu-driven interface to access internet resources. No need to remember or even know complex computer command. User Friendly Interface (?). Largely superseded by WWW, these days.

-- Most Important development to date •World-Wide Web (WWW) released by CERN; Tim Berners-Lee developer. Why is relevant?

Originally developed to provide a distributed hypermedia system. Easy access to any form of information anywhere in the world. Initially non-graphic (this came later, MOSAIC, 1993). Revolutionized modern communications and even our, way of life (?).

•NSFNET backbone upgraded to T3 (44.736 Mbps). NSFNET traffic passes 1 trillion bytes/month and 10 billion packets/month •Start of JANET IP Service (JIPS) using TCP/IP within the UK academic network.

1992 - Multimedia changes the face of the Internet •Number of hosts breaks 1 Million. News groups 4,000 •Internet Society (ISOC) is chartered. •First MBONE audio multicast (March) and video multicast (November). •The term "Surfing the Internet" is coined by Jean Armour Polly.

1993 -- The WWW Revolution truly begins •Number of Hosts 2 Million. 600 WWW sites. •InterNIC created by NSF to provide specific Internet services

directory and database services registration services information services

•Business and Media really take notice of the Internet. •US White House and United Nations (UN) comes on-line. •Mosaic takes the Internet by storm. Why is this relevant?

User Friendly Graphical Front End to the World Wide Web. Develops into Netscape -- most popular WWW browser to date.

1994 -- Commercialization begins •Number of Hosts 3 Million. 10,000 WWW sites. 10,000 News groups. •ARPANET/Internet celebrates 25th anniversary •Local communities begin to be wired up directly to the Internet (Lexington and Cambridge, Mass., USA) •US Senate and House provide information servers •Shopping malls, banks arrive on the Internet

A new way of life You can now order pizza from the Hut online in the US. First Virtual, the first cyberbank, open up for business

•NSFNET traffic passes 10 trillion bytes/month •WWW edges out telnet to become 2nd most popular service on the Net (behind ftp-data) based on % of packets and bytes traffic distribution on NSFNET •UK's HM Treasury on-line (http://www.hm-treasury.gov.uk/) •First cyberstation, RT-FM, broadcasts from Interop in Las Vegas •Arizona law firm of Canter & Siegel "spams" the Internet with email advertising green card lottery services; Net citizens flame back

1995 -- Commercialization continues •6.5 Million Hosts, 100,000 WWW Sites. •NSFNET reverts back to a research network. Main US backbone traffic now routed through interconnected network providers •WWW surpasses ftp-data in March as the service with greatest traffic on NSFNet based on packet count, and in April based on byte count •Traditional online dial-up systems (Compuserve, America Online, Prodigy) begin to provide Internet access •A number of Net related companies go public, with Netscape leading the pack. •Registration of domain names is no longer free. •Technologies of the Year: WWW, Search engines (WAIS development). •RealAudio, an audio streaming technology, lets the Net hear in near real-time RFC 1882: The 12-Days of Technology Before Christmas

Country domains registered: Ethiopia (ET), Cote d'Ivoire (CI), Cook Islands (CK) Cayman Islands (KY), Anguilla (AI), Gibraltar (GI), Vatican (VA), Kiribati (KI), Kyrgyzstan (KG), Madagascar (MG), Mauritius (MU), Micronesia (FM), Monaco (MC), Mongolia (MN), Nepal (NP), Nigeria (NG), Western Samoa (WS), San Marino (SM), Tanzania (TZ), Tonga (TO), Uganda (UG), Vanuatu (VU) Top 10 Domains by Host #: com, edu, net, gov, mil, org, de, uk, ca, au •New WWW technologies emerge

Mobile code (JAVA, JAVAscript, ActiveX), Virtual environments (VRML), Collaborative tools (CU-SeeMe)

1996 -- Microsoft enters •12.8 Million Hosts, 0.5 Million WWW Sites. •Internet phones catch the attention of US telecommunication companies who ask the US Congress to ban the technology (which has been around for years) •The WWW browser war begins , fought primarily between Netscape and Microsoft, has rushed in a new age in software development, whereby new releases are made quarterly with the help of Internet users eager to test upcoming (beta) versions. •The controversial US Communications Decency Act (CDA) becomes law in the US in order to prohibit distribution of indecent materials over the Net. A few months later a three-judge panel imposes an injunction against its enforcement. Supreme Court unanimously rules most of it unconstitutional in 1997. •Various ISPs suffer extended service outages, bringing into question whether they will be able to handle the growing number of users. AOL (19 hours), Netcom (13 hours), AT&T WorldNet (28 hours - email only) •Domain name tv.com sold to CNET for US$15,000 •MCI upgrades Internet backbone adding ~13,000 ports, bringing the effective speed from 155Mbps to 622Mbps. •The Internet Ad Hoc Committee announces plans to add 7 new generic Top Level Domains (gTLD): .firm, .store, .web, .arts, .rec, .info, .nom. The IAHC plan also calls for a competing group of domain registrars worldwide. •RFC 1925: The Twelve Networking Truths •Restrictions on Internet use around the world:

China: requires users and ISPs to register with the police Germany: cuts off access to some newsgroups carried on Compuserve Saudi Arabia: confines Internet access to universities and hospitals Singapore: requires political and religious content providers to register with the state New Zealand: classifies computer disks as "publications" that can be censored and seized source: Human Rights Watch

1997 -- What Next? •19.5 Million Hosts, 1 Million WWW sites, 71,618 Newsgroups. •Domain name business.com sold for US$150,000 •Early in the morning of 17 July, human error at Network Solutions causes the DNS table for .com and .net domains to become corrupted, making millions of systems unreachable. •In protest of the DNS monopoly, AlterNIC's owner, Eugene Kashpureff, hacks DNS so users going to www.internic.net end up at www.alternic.net Technologies of the Year: Push, Multicasting

1998 - •US Depart of Commerce (DoC) releases the Green Paper outlining its plan to privatize DNS on 30 January. This is followed up by a White Paper on June 5 •Network Solutions registers its 2 millionth domain on 4 May •Canada kicks off CA*net 3, the first national optical internet •Compaq pays US$3.3million for altavista.com •ABCNews.com accidentally posts test US election returns one day early (2 November) •French Internet users give up their access on 13 December to boycott France Telecom's local phone charges (which are in addition to the ISP charge) •Open source software comes of age •Technologies of the Year: E-Commerce, E-Auctions, Portals •Emerging Technologies: E-Trade, XML, Intrusion Detection

1999•First Internet Bank of Indiana, the first full-service bank available only on the Net, opens for business on 22 February •IBM becomes the first Corporate partner to be approved for Internet2 access •European Parliament proposes banning the caching of Web pages by ISPs •US State Court rules that domain names are property that may be garnished •MCI/Worldcom, the vBNS provider for NSF, begins upgrading the US backbone to 2.5GBps •A forged Web page made to look like a Bloomberg financial news story raised shares of a small technology company by 31% on 7 April. •First large-scale Cyberwar takes place simultaneously with the war in Serbia/Kosovo •The Web becomes the focal point of British politics as a list of MI6 agents is released on a UK Web site. Though forced to remove the list from the site, it was too late as the list had already been replicated across the Net. (15 May) •Activists Net-wide target the world's financial centers on 18 June, timed to coincide with the G8 Summit. Little actual impact is reported. •business.com is sold for US$7.5million (it was purchased in 1997 for US$150,000 (30 Nov) •Technologies of the Year: E-Trade, Online Banking, MP3 •Emerging Technologies: Net-Cell Phones, Thin Computing, Embedded Computing •Viruses of the Year: Melissa (March), ExploreZip (June)

2000•The US timekeeper (USNO) and a few other time services around the world report the new year as 19100 on 1 Jan •A massive denial of service attack is launched against major web sites, including Yahoo, Amazon, and eBay in early February •Web size estimates by NEC-RI and Inktomi surpass 1 billion indexable pages •Hacks of the Year: RSA Security (Feb), Apache (May), Nike (June) •Technologies of the Year: ASP, NAPSTER?, IPV6? •Viruses of the Year: Love Letter (May) •Current up to date web user statistics

Framework for Global Electronic CommerceFramework for Global Electronic Commerce

A Framework for Global Electronic Commerce was released in 1997

It’s release underscores the importance of Internet-based commerce in the global economy

It outlines several guiding principles for e-commerce planners and strategists

Table 1-3

Table 1-4

Features of CommunicationFeatures of Communication

Four things required• Sender, receiver, medium, and message

Types of messages• File• Request• Response• Status• Control• Correspondence

Understandability Error Detection

Network ApplicationsNetwork Applications

The network applications environment consists of several important components:• Application programs• Operating systems• Data communication systems• Database management systems

The application environment is illustrated in Figure 1-10

Figure 1-10

Online System RequirementsOnline System Requirements

Response TimeThroughputConsistencyFlexibility

Online Systems Requirements ContinuedOnline Systems Requirements Continued

AvailabilityReliability

• Mean time between failure (MTBF)

• Mean time to repair (MTTR)

• Fault Tolerance

RecoverySecurity

Business Data Communication ApplicationsBusiness Data Communication Applications

Major data communication applications include:

• E-mail

• Groupware

• Knowledge management systems

• E-commerce and e-business applications

• Wireless applications

Groupware ApplicationsGroupware Applications

Group calendar systems

Electronic filing cabinets

Project management software

Group support systems

Electronic meeting and videoconferencing systems

Document management systems (image processing systems)

Other Data Communication ApplicationsOther Data Communication Applications

Batch applications

Data entry applications

Distributed applications

Inquiry/response applications

Interactive applications

Sensor-based applications

Combined applications

Application Service Providers Application Service Providers

Many businesses have turned to third-party services for some or all of their business and data communications applications

Application service providers (ASPs) are third-party organizations that manage and distribute software and services to other companies over the Web

Many ASPs specialize in integrated e-commerce and e-business applications

Business Data Communications IssuesBusiness Data Communications Issues

Major data communications issues include:• Cost-effectiveness• The Internet• Bandwidth• Evolving technologies• Convergence• Standards• Privacy and security

Important Standard-Setting OrganizationsTable 1-5Important Standard-Setting OrganizationsTable 1-5

Business Data Communication CareersBusiness Data Communication Careers

There are numerous job opportunities and career paths for individuals interested in data communications and networking

Table 1-6 includes examples of data communication job titles

Table 1-7 summarizes some of the major professional certifications for networking and data communications specialists

Introduction to NetworksIntroduction to Networks

Can be defined as a single computer , called a host, together with communication circuits, communication equipment, and terminals.

There are many different types of network configurations (see figures1-4 to 1-8)

Key Data Communication ConceptsKey Data Communication Concepts

Session: communication dialog between network users or applications

Network: interconnected group of computers and communication devices

Node: a network-attached computer Link: connects adjacent nodes (see Figure 1-4) Path: end-to-end route within a network Circuit: the conduit over which data travels Packetizing: dividing messages into fixed-length

packets prior to transmission over a network’s communication media

Routing: determining a message’s path from sending to receiving nodes.

Store-and-Forward SystemsStore-and-Forward Systems

Messages may be stored at intermediate nodes along the transmission path between sender and receiver in store-and-forward systems• This helps ensure message delivery without

obligating the sender to wait until a message is delivered before transmitting other messages

• It also helps ensure message delivery in the case of link or destination failure while the message is in transit

• Store-and forward algorithms are valuable in time-staged delivery systems and in networks that assign priorities to different messages

Network Topology, Architecture, and ComplexityNetwork Topology, Architecture, and Complexity

Network topology refers to the physical layout of a network, the way that nodes attach to the communication medium

Network architecture refers to the way in which media, hardware, and software are integrated to form a network

Network complexity is concerned with extent to which network architectures are simple or diverse in their make• Figures 1-5, 1-6, and 1-7 illustrate various levels of

complexity

Figure 1-5

Figure 1-6

Telecom ChannelsTelecom Channels

Channels - the links by which data or voice are transmitted between sending and receiving devices in a network• twisted wires• coaxial cable• fiber-optic cable• backbone• wireless

• microwave• satellite

Telecom Channels – other WirelessTelecom Channels – other Wireless

Cellular Mobile data networks (2-way) PCS (personal communication systems)- to

the end user acts like cellular, but different Personal data assistants smart phones

Transmission SpeedsTransmission Speeds

Medium Speed CostTwisted Wire 300 bps-10 Mbps Low

Microwave 256 Kbps-100 Mbps

Satellite 256 Kbps-100 Mbps

Coaxial Cable 56 Kbps-200 Mbps

Fiber-Optic Cable 500 Kbps-10 Gbps High

Data Communication FrameworksData Communication Frameworks

Two major data communication frameworks have been developed to help ensure that networks meet business and communication requirements:• Open Systems Interconnection (OSI) reference

model developed by the International Standards Organization (ISO)

• Transmission Control Protocol/Internet Protocol (TCP/IP) suite

History of the OSI ModelHistory of the OSI Model

Open Systems Interconnected Model• was created in the 70’s by the ISO (although the

CCITT came up with their own model)• 10 different people got together and considered all

functions of communications

• was created because people realized that our computers needed to talk to each other(and there was no one dominant computer system)

• ISDN was a big factor• 7 layers = 4 upper and 3 lower

OSI Reference Model in PracticeOSI Reference Model in Practice

The OSI reference model is used in many ways:• To provide assistance when troubleshooting

network problems

• To provide a common terminology and framework for networking technology developers

• To facilitate the development of connectivity standards needed for flexible open architectures

• To enable the development of protocol stacks that allow network nodes to communicate with one another

The OSI ModelThe OSI Model

LAYER 7– APPLICATION The visual interface level between the user and the network, or computer. (Ex Word, Excel, Access, Email)

LAYER 6-- PRESENTATIONThis layer is responsible for converting the visual interface into a code that is then sent through the computer or network. For example, this layer may convert ASCII code (what many applications like Word use) to an 8-bit code.

LAYER 5 – SESSION This layer keeps track of whose turn it is to receive traffic, basically it is a dialog control. This is the level that acknowledges receipt of a transmission as well as sends the message to the network.

LAYER 4 – TRANSPORT All streams of data are received and combined into one single stream so that data may be sent through the network. Multiplexing and demultiplexing occurs on this layer.

THE OSI MODEL

LAYER 7 ApplicationLAYER 6 PresentationLAYER 5 SessionLAYER 4 Transport

LAYER 3 NetworkLAYER 2 Data LinkLAYER 1 Physical

The OSI ModelThe OSI Model

BOTTOM/LOWER LAYERS LAYER 3– NETWORK

On this level the router exists to determine if the message is meant for the system or if it needs to be redirected to its final destination. This is done by a header system, which is programmed to accept or reject depending if the header is the one used by the network.

LAYER 2– DATA LINK There is where a check of the message occurs. That is the message is checked for the proper frame, formation, synchronization, power level, voltage, and wavelength. If the test is a successful, the message is sent to the network layer to determine if the message is truly meant for the system.

LAYER 1– PHYSICAL Where the actual physical makeup of the message is identified. That is the duration of bits, the right number of bits, and the right wavelength is checked. As with the other two layers, if this test is successful, the message is sent up the chain.

THE OSI MODEL

LAYER 7 ApplicationLAYER 6 PresentationLAYER 5 SessionLAYER 4 Transport

LAYER 3 NetworkLAYER 2 Data LinkLAYER 1 Physical

OSI LAYER INTERACTIONSOSI LAYER INTERACTIONS

Application Process DATA

Application Process Incoming Frame

Reduction

Outgoing Frame Application PCI DATA Application

Construction Presentation PCI APDU Presentation

Session PCI PPDU Session

Transport PCI SPDU Transport

Network PCI TPDU Network

Link PCI NPDU Link

Physical Physical

encoded bit stream

TCP/IP Protocol SuiteTCP/IP Protocol Suite

The TCP/IP suite provides insights into the inner workings of the Internet

Like the OSI model, the TCP/IP suite is layered• Because the protocols found at each layer are

independent of those at the other layers, a given protocol can be modified without affecting those found at other layers

• TCP/IP layers and layer-specific protocols are illustrated in Figure 1-9

Moving Bits through the NetworkMoving Bits through the Network

Analog Signal

1

0

Digital Signal

1 1 1

0 0 0

digital analog digital Computer Modem Modem Computer

telephone lines

Putting It all TogetherPutting It all Together

Data Communications Supports Applications

The Operating System manages the resources of the computer.

There must however, be a system that provides a bridge between applications and the devices so they can communicate—this is called a Transaction Control Process (TCP)

Introduction to computer communication networksIntroduction to computer communication networks



Protocol

A protocol is a series of steps, involving two or more parties, designed to accomplish a task

Everyone involved in the protocol must know the protocol and all of the steps to follow in advance

Everyone in the protocol must agree to follow it The protocol must be unambiguous; each step must be well

defined and there must be no chance of a misunderstanding. The protocol must be complete; there must be a specified

action for every possible situation.

Communication Protocol Model

A template to describe a protocol It has three components

Address: naming Format: messages Behavior: rules Protocol Model

Address: - how to name a partner

Format: - specify the message formats

Rules: - specify the behaviors of the protocol - what should be done when something happens

Address: phone number xxx-xxxx

Format: English

Rules: - dial when initiating - pick up phone when ringing - ...

Phone conversation Protocol

Protocol Example: PhoneProtocol Example: Phone

Can a single protocol do it all?

Computer communication has to deal all sorts of problems Electrical/Optical signals/noise Errror detection and recovery medium control access message boundary routing, fragmentation flow control (net congestion) loss and duplicated messages synchronization representation application specific

Yes. It can be done but how to develop in timely fashion (debug, verify and low cost) how to maintain it how to extend and evolve it

Layered Approach

Divide and conquer partition into multiple layers of software each layer has clear programming interfaces

each interface provides a service to adjacent layers each layer solves a limited set of problems each layer encapsulates the related details

Pros reduce complexity, isolate changes, promote

manageability Cons

efficiency

ISO Reference Model

Not every layer is created equal physical and data link are hardware heavy network and transport are software heavy session and presentation are typically light layers

Some functions occurs inmultiple layers: + Error handling may be in every layer + Flow control can be in multiple layers

Layer Number Layer Name Problems to Be Solved

7 Application layer application specific (Lab #2)6 Presentation layer data representation (XDR)5 Session layer synchronization & dialog (client/server)4 Transport layer reliable delivery of messages (sockets)3 Network layer routing & fragmentation2 Data link layer medium access control & framing1 Physical layer signaling, physical connections

ISO vs. TCP/IPISO vs. TCP/IP

1. Physical

2.Data Link

3.Network

4.Transport

5.Session

6.Presentation

7.Application

Host to network

Internet

Transport

Application

Physical layer protocols

Highly physical network technology dependent Main tasks

define the signaling protocol what is the meaning of 1s or 0s

voltages or frequencies what is bad signals

define the physical connections required RS232 connectors for RS232 serial line communication RJ45 or BNC connectors for Ethernet

define the communication media define the network topology

Physical Network Technologies

Circuit-switched network (CS) connection-oriented network

establish connection before communication once communication established, a circuit line is

reserved for the communicating partners example: telephone network

Packet-switched network (PS) store-forward based network

packet sent from a node to another node the intermediate node stores the packet and decides to

forward to another node towards the destination no circuit line is reserved example: Ethernet

Circuit connection

in out

In Out

3 24 1

Routing table

In Out

2 4

Routing table

In Out

2 4

Routing table

In Out

2 23 4

Routing table

Host A

Host B

Comparisons: CS and PS

Circuit-switched Packet-switched

line resource dedicated shared performance guaranteed averaged cost expensive less adaptive routing not easy easy switch device highly complex simple reliability high higher utilization low higher

Network Types by Scope

WAN wide area network cross large span of space (continental) typically heterogeneous and low speed example: Internet

MAN metro-area network regional scope (city-wide)

LAN local area network limited scope (a couple of buildings) typically homogeneous & high speed example: Ethernet & Token ring

Network Transmission Medium

Open air radio, microwaves, satellites, infrared noise signals, collision

Optical clear signals, low power and high rate (Gbps)

Copper wire Lower cost interfaces Bi-directional

Bus Network Topology

Every nodes tap into a common medium Signals may collide with each other

need to arbitrate who will get the bus capable of broadcasting message (one send & many listen) the common medium is the bottleneck

single node failure causes no network failure the medium failure brings down the network

Example: (old, 10BASE2, 10BASE5) Ethernet

common medium

Cable ModemCable Modem

Star Network Topology

One node at the center as the master node Other nodes linked to the master as slaves

slaves communicate via master easy to arbitrate among slaves (master decides) not scalable (the master is the bottleneck) normally for small networks or that requires predictable

performance master failure shutdowns the whole net

Example: Ethernet, DSL

Master

slave

slave

slave

slave slave

Ring Network TopologyRing Network Topology

Nodes are arranged in a ring One node receives from its predecessor &

sends to its successor• arbitrate who can access the ring

• messages forwarded by each node

• sender deletes its messages from the ring

• the common ring is the single point of failure (complicated

connectors needed)

Mash Network TopologyMash Network Topology

Nodes are arranged in grids

• each node can talk to its neighbors directly

• non-neighbor nodes needs store-and-forward for communication

Hyper Network TopologyHyper Network Topology

No restrictions on how to link the nodes Topology can adapt to individual organization

needs

Master

slave

slave

slave

slave slave

Data Link Layer Protocols

Main tasks medium access control

arbitrate who can use the transmission medium framing

define the boundaries of a packet

Physical technology dependent (like physical layer) typically implemented in hardware or firmware when you buy a network card, you get both physical

and data link layer protocols in the card

Introduction to Internet and TCP/IP

Introduction to Internet and TCP/IP



Motivations for Internet

Observations: Different physical networks everywhere

connection between limited hosts different needs for different technologies legacy networks

Limited connectivity each physical technology has its limits

Different technologies use different “languages”

Need for a uniform virtual network universal connectivity every host speaks the same language independent of

physical networks

Virtual Network over Physical Networks

…...Ethernet Token Ring ATM

Internet Protocol (Network layer)

Internet

Virtual network

Physical network

hosts

Design Goals of Internet A virtual (global) network

independent of physical technologies independent of locations universal language

Universal connectivity every host is equal no matter of

its architecture and system origin its physical network attachment

Scalable growth without limits

Robust no single point of failure

Problems to be Solved

Universal naming how to translate the universal name to local name

used by local physical network?

Routing how to route IP packages among different local

networks to reach the destination?

Fragmentation different physical networks use different package

sizes. how this should be handled?

Error handling

Internet Architecture

Internet: ‘‘the mother of all networks’’

THE network of (interconnected) networks Physical networks interconnected via gateways Gateway(router) is a host glues nets together

attached to multiple nets forward IP packages between nets

Token Ring

Gateway

Ethernet

Other nets Gateway

IP Packet Format

IP packet consists of header and data portions

IP header IP data portion

V HL type total length

Identification F frag. offset

TTL prot header cksum

Source IP address

Destination IP address

options if any

IP Header Format

IP Address IP address specifies a connection to a network instead

of a host IP address == NetID + HostID

Dotted notation each byte in an IP address represented as a decimal bytes are separated with a period (.) example: 152.15.35.44

Classes

0 8 16 24 31

0 NetID HostID

10 NetID HostID

110 NetID HostID

1110 Multicast address

11110 reserved for future use

class A

class B

class C

class D

class E

How do computers talk to each other on an ethernet bus

Each computer on the internet as a unique IP address. Each network interface (e.g. ethernet card) has a unique

address 8.2.1.1 wants to send a message 8.2.1.3

It yells “yaahoo, who is 8.1.2.3” Each computer listens to messages on the bus (collision detection

and resolution) for “yaahoo” 8.2.1.3 replies to 00550DA2F5D82 “I am 02950JX2F5Y82” 8.2.1.1 sends the message to 8.2.1.3.

8.2.1.1 8.2.1.2 8.2.1.3

00550DA2F5D82 02550JA2F5D82 02950JX2F5Y82

IP Routing

Principles Route packages according to their destination IP net ID Forward packages hop by hop

each gateway has the routing knowledge of its nearby neighbors

hosts route packages to gateway and gateway does the rest.

Routing types direct routing

If the destination net ID is the same as the local net ID, no routing to gateway is needed and send the package via underlying physical network

indirect routing if the destination net ID is different from the local net ID, send

the package to an appropriate gateway.

IP Rules

Fragmentation rules if underlying net size < packet size & not final dest

break packet into small packets and send them if final dest is reached & packets are fragmented

reassemble fragmental packets into original size Error rules

if IP header is erroneous, drop/report it

Table-Driven IP Routing

Each IP host has a IP routing table each entry associates a destination net ID with a

forwarding gateway each route has a performance metrics

number of hops to reach the destination

Route table for 152.15.36.9

152.15.x.xuncc

ncsu

152.15.254.254

163.29.x.x

163.29.10.88

152.15.36.9

152.15.35.1net3

e0

Dest. Net ID Next hop host

NIF

163.29 152.15.254.254

e0

Default 152.15.35.1 e0

Routes in an IP Routing Table

Next-hop routes the destination is an IP net ID: a packages

addressed to any host in the net, send to the associated gateway

Host-specific routines the destination is a complete IP address: route all

packages to the specified host via the associated gateway

Default routes the catch all routing: all packages not specified by

the above, send the gateway associated with the default route.

the gateway associated with the default route is called default gateway

Topology of the internet

net: 9.1.1.x

net: 8.2.1.x

9.1.1.3

net 1.1.1.x

net 2.1.1.x

net 3.1.1.x

9.1.1.2

9.1.1.4

9.1.1.18.2.1.1

8.2.1.2 8.2.1.3

8.2.1.4

d

cb

a

1 2 3

4hardware addresses

Sub-netting

All hosts in a network must have the same net work number

As the number of networks grow, so does the need for net work numbers

Solution: subnet, divide the host name portion of the IP address into subnet id and the host

Subnet mask and routing table.

Intranet example: home networkingIntranet example: home networking

Router

PC

PC

PC

Broadband provider

Internet

Internet IP Address

Intranet IP address

Intranet IP address

Intranet IP address

Intranet IP address

PPP protocol (phone dialin)

Computer (client) dials to a modem. Computer on the other (ISP server) end

is on the internet. The ISP server assigns an ip address for

the dialing computer All messages send from the client are

routed by the isp host to the rest of the internet.

DHCP protocol (most ethernet)

Client sends a message (on the local bus) to a DHCP server requesting an IP address for the session

DHCP server assigns an ip address

IP Fragmentation

IP packages are broken to fit underlying physical network when a package is sent

locations of fragmentation original package sender gateways that forward the package

IP packages are reassembled at the final destination

gateway

fragment

net 1 net 2

assemble

IP Fragmentation Example

IP header 800 bytes 800 bytes 250 bytes

Original IP datagram

IP header(fragment 1)



800 bytes

800 bytes

250 bytes

Fragment 1 (offset 0)



fragmentation

ISO vs. TCP/IPISO vs. TCP/IP

1. Physical

2.Data Link

3.Network

4.Transport

5.Session

6.Presentation

7.Application

Host to network

Internet

Transport

Application

Transport Layer

Why do we need a transport layer? Network layer provides delivery only

from a host to a host in a best effort fashion

Users want to transport data from application to application in a reliable delivery

Transport layer fits the gap between user needs and IP messaging

provide communication endpoint for applications deliver messages reliably

Problems to Be Solved in Transportation layer

Missing packets Duplicated packets Out of order packets Flow control Synchronization

Reliable Delivery via Unreliable Networks

Missing packet acknowledge and timeout retransmission

Duplicate messages sequencing packets

Out of order messages sequencing packets

Flow control wait and stop window-sliding

Synchronization hand shaking

Transport Protocols in TCP/IP

User Datagram Protocol (UDP) provide communication endpoint for applications best effort delivery of messages (packets) message boundary is observed the protocol embedded in Internet Datagram sockets

Transmission Control Protocol (TCP) provide communication endpoint for applications reliable delivery via connection-based

communication no message boundary between packages the protocol embedded in Internet Stream sockets

Establish a TCP Connection

Three way handshakingapplication 1 application 2

TCPpack p;p.codebit=SYN;p.seq_no = x; p.winsize=S1;send (p);tcp_state=SYNSENT;receive(p);

p.ack = p.seq_no + 1;p.seq_no = x++;send(p);tcp_state=ESTABLISHED

syn+x

TCPpack pack;tcp_state=LISEN;receive(pack);

pack.ack=pack.seq_no+1pack.seq_no = y; pack.winsize=S2;send(pack);tcp_state=ESTABLISHED;

syn+ack+y

ack

Denial of service attacksDenial of service attacks

Exploits the TCP session establishment protocol.

An attacker will send syn, but never sends ack. This type of attack is also called “sync flood”.

Synchronized attacks launched on multiple (often victim) machines.

TCP Retransmission Sender

is free to divide user stream data in packets expects an ack for each packet sent starts a timer when a packet is sent upon an ack reception, advances seq_no expected upon a timer expiration, resends the packet

Receiver sends an ack whenever a packet is received deletes the packet if it duplicated is free to pass acknowledged packets to user is forced to pass to user the data when receives a

PUSH

Chapter 6Key Technology of Digital

Manufacturing

Chapter 6Key Technology of Digital

Manufacturing



Key Technology of Digital ManufacturingKey Technology of Digital Manufacturing

This Chapter will discuss the key technologies of digital manufacturing science from five aspects, including:

various digital technologies in the product lifecycleresources and environment technology facing digital manufacturemanagement technology in digital manufacturing process and systemcontrol technology in digital manufacturedigital recognition and integration technology in products, binding the key characteristic of digital manufacturing science’s development.

Various Digital Technologies in Product LifecycleVarious Digital Technologies in Product Lifecycle

CAD/CAE/CAPP/CAM and Integrated Modeling of CAx System

With the development of network technology and information technology as well as the exchanging and sharing between multimedia visual environment technology, product data management (PDM) system, distributed cooperative design and cross-platform, cross-regional, synchronous and asynchronous information, group collaboration and intelligent design between multi-enterprises, multi-teams, multi-people and multi-applications have obtained deeper research and entered practical stage.

Digital Equipment and Digital Processing Technology

Various Digital Technologies in Product Lifecycle

Digital Equipment Technology:

Typical digital devices include numerically-controlled machine tool, machining center, industrial robots, digital measurement and detection devices, rapid prototyping devices and so on.

1. Digitized modeling of equipment2. Digital equipment’s networking

Digital Processing Technology


Fig. 8.3 The composition of digital processing

The Technology of Digital Maintenance and Diagnosis

Fig. 8.5 The key technology of product digital maintenance


Fig. 8.7 The Function of Remote Failure diagnosis system


The Technology of Digital Maintenance and Diagnosis

The key technologies of digital logistics:

Logistic informatization: Related technology includes bar code technology, network communication technology, database technology, electronic commerce technology, enterprise resource planning, etcLogistic intelligence: It refers to using intelligent integrated technology, making logistic system have the ability of thinking, perception and reasoning judgment, thus resolving the problems in logistic operation Logistic Virtualization: It refers to the description and expression on essence of actual logistic process. Its foundation is to use computer emulation and virtual reality technology to express, model and emulate all effective logistic behavior and factors, and to depend on group cooperative work on computer to establish 3D full-digital model of the whole logistic process, in order to realize the analysis and evaluation of logistic process in logistics design stage


Key Technology of Digital Logistics

Fig. 8.8 The structure of digital logistic system


Digital Logistic Supporting System Digital logistic management platform: The platform realizes the

logistic operating digitalization between enterprise interior, alliance partner and customer, which carries out intelligent and digital management (DM) to enterprise logistic process

Warehouse management system: The system improves traditional warehouse enterprise and carries out effective management and disposal to goods. Realizing the electronization of warehousing work flow is the most important function of the system

Transportation management system: The system is the logistic transportation management software which is designed by an overall measurement, analysis and standard haulage operation process and the use of modern logistic management method based on network environment.

Distribution management system: This system has functions on delivery of central work flow as well as logistic management


Resource and Environment Technology inDigital ManufactureResource and Environment Technology inDigital Manufacture

The Sharing of Digital Manufacture ScienceThe manufacturing resource information sharing based on STEP

Resource Organization and Management Technology


The manufacturing resource information sharing based on network

Resource Organization and Management Technology


The product information integration base on XML

The Integration of Digital Manufacturing Resource


PDM system and its integration

The Integration of Digital Manufacturing Resource

At present, the integration patterns between PDM and ERP mainly have the following three kinds:

•The package integration of application system. The application tools access data document with corresponding format from PDM system, which is called encapsulation

•The two-way transmission of document. With the effort of PDM and ERP system’s developer, nowadays the most advanced PDM system carries on seamless two-way transmission between product data and related document data as well as ERP system

•Through mode. It is very effective to integrate independent PDM and ERP system through file transfer, which contradicts the principle that data must be stored in the same location to keep all documents clear and avoid data inconsistency. Because the bottom layers of PDM and ERP systems are all relational databases, and the data about product is stored in each domain, the so-called through mode is that the two systems directly carry on operation to the data of database and exchange data.

Manufacturing Grid: the Management and Scheduling of Resources

Resource and Environment Technology inDigital Manufacture

Manufacturing grid is a kind of specific materialized form of modern integrated manufacturing and agile manufacturing mode in global and networked economic environment.

Its approach is to use grid technology, information technology and computer and advanced management technology, in order to overcome the obstacles which the distance in the space brings and achieves the connectivity of all of the geographically dispersed manufacturing resources through grid


The Architecture of Manufacturing Grid

The Prototype System of Manufacturing Grid


Management Technology in the Digital ManufacturingProcess and SystemManagement Technology in the Digital ManufacturingProcess and System

The Digital Resource Management System ERP in Digital Manufacturing

ERP is the most effective mode to realize the DM of enterprise. First of all ERP is a DM concept; secondly ERP is a practical management tool. Its effect is realized based on the following aspects in the enterprise manufacturing process.

Implementation of ERP system in enterprise, which realizes the essential conversion of production manufacturing management model in enterprise through implementation of advanced management modes such as MRP, JIT and PDM.

We use CIMS thought to complete the integration through the CAD/CAM,

CAPP, MAS (manufacturing automatic system), CAQ (computer-aided quality) of PDM (product data management) and TIS (technology information system), making the digital design of product integrate with digital manufacturing

Suppliers/Vendor

• Supplier chain• Purchasing

Customer Support

• Pre/Post Sales Support

ISO ApprovalReview,

Design Release

• Digital Design Review• View & Markup• Recognition• Audit

Account / Finance

• Costing• Define

incentive program

Sales &Marketing

• Quick Response• Marketing Proposal• Easy to quote• Presentation• Product Launch

HumanResource

• Training• Corporate Communication• Staff Development• Virtual Learning

EngineeringDesign

• CAD/CAM• CAE / FEA• Prototyping

IT Research & Development

• Technology• Methodology• Integrating

Distribution

• Fulfillment• Delivery

Manufacturing/AssemblyShop floor

• Product Assembly/Disassembly Sequencing

• Robotic/Work Cell Animation• Digital Factory

Factory Manager/ Production

Planner

• Actual vs. schedule• Scheduling• Work-to-lists• Route cards

Quality Control

• Defect Analysis• Quality Control

e-Manufacturing BOM

P L M

Management Technology in the Digital ManufacturingProcess and SystemManagement Technology in the Digital ManufacturingProcess and System

The Property Right Protection of Network Manufacturing Product Based on Digital Watermarking TechnologyThe Property Right Protection of Network Manufacturing Product Based on Digital Watermarking Technology

Control Technology in Digital ManufactureControl Technology in Digital Manufacture

1. Networked Control System


2. Virtual NC Technology


3. The Embedded Control Technology

Digital Recognition and Integration Technology in ProductDigital Recognition and Integration Technology in Product

Radio-Frequency Identification Technology

Bar Code Recognition Technology

Electromechanical Integration Technology and the Light

Mechanical and Electrical Integration TechnologyThe Electromechanical Integration TechnologyThe Light Mechanical and Electrical Integration Technology

Digital Recognition and Integration Technology in Product

Digital Recognition and Integration Technology in Product

Data Communication & Networking in Manufacturing System

Documents