CAD/CAM system in terms of hardware classification
- 2. Topics Outline • Introduction to type of systems • CAD/CAM system evaluation criteria-system consideration • Hardware Integration and Networking • Programmable Logic Controller 2
- 3. • At the end of chapter, students should be able to: • Understand and describe CAD/CAM system in terms of hardware classification. • Discover the knowledge of hardware integration and networking Learning Objectives 3
- 4. CAD/CAM SYSTEM Classified based on: Hardware system which focusing on the type of host computer that drives the system TYPE OF SYSTEMS Mainframe-Based Systems Large data storage Expensive Need interface language No user control Good for large corporations Networked Mini-computer Based Systems Higher data storage than micro-computer Expensive, but much less than mainframe Multiple users control at one time Good for large corporations Networked Micro-computer Based Systems Limited data storage Inexpensive Run on MS-Windows User controlled Good for all users Can be networked Workstation-Based Systems Medium size data storage Relatively inexpensive Runs on Unix No user control Good for small corporations Networked 4
- 5. CAD/CAM SYSTEM EVALUATION CRITERIA 1. Geometric modelling capabilities 2. Design documentation 3. Applications 5
- 6. 1. Geometric modelling capabilities 1. Representation Techniques • The representations of modelling include wireframes, surfaces and solids (2D and 3D geometry). • Capability of integrating various representations and the applications. 2. Coordinate Systems and Inputs • Able to provide various types of coordinate systems and coordinate inputs • Designer able to define the proper planes of constructions • Coordinate inputs can take the form of Cartesian (x, y, z), cylindrical (r, Ө, z) and spherical (Ө, φ, z). 4. Geometric Editing and Manipulation • Editing functions must have INTERSECTION, TRIMMING and PROJECTION. • Manipulations must include TRANSLATION, ROTATION, COPY, MIRROR, OFFSET, SCALING and CHANGING ATTRRIBUTES. 3. Modeling Entities (parts, component, model, etc) • Easy to generate, verify and edit the entities should be considered during evaluation. 5. Graphic Standards Support • CAD/CAM system must support exchange standard if geometric models’ are to be transferred from one system to another • Attractive features include tools, jigs and fixture designs, or generating NC part programs. 6
- 7. 2. Design documentations 3. Applications Generation of Engineering Drawings Facilitate in time-consuming activities to generate engineering drawings. Able to generate various view- orthographic projection (top, front and right side) Assemblies or Model Merging Easy to assemble the model to generate assembly drawings Easy to modify and clean-up the resulting assembly. Design Applications Capabilities of the design packages to be integrated and interfaced with geometric databases The design packages include mass property calc, tolerance analysis, FEM and analysis, etc Manufacturing Applications Has fully integrated system between CAD and CAM. E.g: tool path generation & verification, NC part programming, postprocessing, CAPP, group technology, CIM apps & robot simulation. Programming Language Supported Has robust and stable syntax of graphic commands when they are used inside and outside the programming languages. Users are required to refer to the software handbook for better understanding 7
- 8. Why it is important? The integration & networking between the various components and peripherals of a system ensure the success of CAD/CAM installations. The hardware components between design and manufacturing department must communicate together and have access to common databases. To share common resources and peripherals (e.g. plotters and printers) To network (connect) devices that complement each other: connecting a high-end CAD/CAM system to a low-end system to allow database transfer. HARDWARE INTEGRATION AND NETWORKING Introduction 8
- 9. HARDWARE INTEGRATION AND NETWORKING Local Area Networks (LAN) Definitions A data communication system that allows various types of digital devices to talk to each other over a common transmission medium. 1. Efficiency of the related operating system • Incorporates virtual memory management to provide any node on the network with all disk capacity on it • Support a wired range of protocols & file-access procedures 2. Communication speeds • Related to the system of transmission utilized in the network, whether it is synchronous or asynchronous. • Standard speeds: 300, 1200, 4800, 9600, 15,600 baud (1 baud = 1bps) 3. Communication protocols • A CAD/CAM system’s LAN supports to prevent system isolation from other computing facilities. • The format or language used by network to transmit the desired information through the network cables or lines. Local Area Networks (LAN) 9
- 11. HARDWARE INTEGRATION AND NETWORKING Type of LAN Configurations 1. Star LAN 2. Ring LAN 3. Bus LAN Consists of a central computer to which several workstations and central peripherals are attached Typical for workstations supported by mainframe or superminicomputers and which do not have disks Advantage: Provides a central database which is accessible by all users Disadvantage: The whole network fails with the failure of the central computer Well suited when devices are mostly similar (e.g: standalone workstations) Example: Prime Ringnet and the Apollo Domain network Advantages: • Databases or files on one workstation can be shared by others in the network. • If one workstation goes down, the rest remain operational An open-loop system which may take the form of a main bus or branched or tree systems. Suited when devices to be connected are mostly dissimilar. Advantages: • Easy to setup and extend. • Less costly. Less cabling needs. Disadvantages: • If the single network cable has a problem or disconnection, the whole network breaks. • Difficult to identify a problem. Local Area Networks (LAN) 11
- 12. a) Star LAN b) Ring LAN c) Bus LAN d) Hybrid LAN configuration 12
- 13. 1979- Xerox Ethernet Illustration Source:https://www.news.xerox.com/multimedia/photo?fid=5023e658 29371a4cae0003ce&album_id=5023acb029371a4cae000030 13
- 14. PROGRAMMABLE LOGIC CONTROL (PLC) An electronic device which uses a programmable memory to perform specific functions such as Timing, Counting and Logic sequencing. PLC in Industrial Applications Flow line conveyor systems Injection moulding Cement processing Food processing Energy management Welding Grinding What is PLC? 14
- 15. Basic Components of PLC Programming Device Memory Power Supply Processor Input / Output Interface INPUT The input interface will receive process and machine signals and convert them into a form acceptable and understandable by PLC. OUTPUT The output interface converts PLC control signals into a form that is acceptable and understandable by processing equipment. How does it works? Basic Components of PLC 15
- 16. Programming Device Processor Memory Input / Output Interface Industrial Equipment Power Supply Component Descriptions Processor • Executes the various logic functions to perform operations on inputs and determines appropriate outputs. • Has mathematical decision-making capabilities. Memory • Stores the programme that is loaded into the PLC through a programming device. Programming device • Cathode Ray Tube: permits the programmer to use PLC languages to input the control logic into memory. Power Supply • Acts as a source of power for the output signals • Protect PLC against noise in the electrical power lines. Hardware Configuration of PLC 16
- 17. Familiar to the electricians working in the shop floor, control engineers and maintenance personnel Relay ladder diagram Make use of logic statements to establish relationships among PLC inputs and outputs (AND, OR). Boolean- based languages Include statements such as LOAD, OR, AND and often requires the assistance of a computer programmer. Mnemonic languages PLC Programming 17
- 18. Control Relay Function It generates output signals according to logical operations performed on input signals Timing functions To generate output signals a specified time delay after the Input signal is given Analog Control Function Performs integration differentiation and other logical operations Arithmetic Function Performs all mathematical operations Counting Function Adds up number of inputs and generates programmed output. Functions in PLC 18
- 19. PLC • Can be interfaced with industrial processes • Can withstand noise, vibration, humidity, electrical disturbances and temperatures. • PLCs use relay ladder diagrams and other as programming languages Computer • Requires special arrangements for connection with processing equipment • Difficult for computers to work in such an environment • Computer languages are totally different which use high level languages. Advantages of PLC Programming is easier Reprogramming is possible Requires less floor space Maintenance is easy Better reliability Can be interfaced with plant computer system PLC vs. Computer 19
- 20. Thank you! Any question? Next Chapter… CAD/CAM Software 20