THE UNIVERSITY OF OXFORD

Steve Kennedy

Description

• cours magistral
• cours magistral - matière potentielle : p

TWO LECTURES P O P U L A T I O N , T H E U N I V E R S I T Y O F OXFORD, 1 Y EASTER TERM, 1623. NASSAU 7TTILPdARI SENIOR, 1.I'i'F. l~ELI.OI!' OOF > I A C . l > A L I ~ N C O L L E G E , A.M., P K O F E S 9 0 R OY P O L l T I C A L ECONOhIS.

• necessaries
• original proposi- tion
• positive check
• simi- lar climates
• capacity of increase
• human race
• only check to the increase of the irrational animals
• population
• society

Sujets

• Cours magistral
• Thomas Malthus
• England
• Europe
• Population
• Irrationality
• Animals
• Society
• Climate
• Necessary

Informations

• Publié par: meshang
• Nombre de lectures: 20
• Langue: English

Extrait

Experion Custom Algorithm Block An Evolution in Control Language

Honeywell’s robust Custom Algorithm Block (CAB) Improve Engineering Efficiency with a Powerful development environment allows users to define custom Development Environment control strategies, offering flexible and tight control using Honeywell’s CAB development environment is built upon complex calculations. These blocks supplement standard Microsoft® Visual Studio® software. The CAB Developer Experion™ platform function blocks and are easily tool extends features of the Visual Studio environment to implemented within an Experion Application Control provide an industrial controloriented environment tightly Environment (ACE) node. integrated with Honeywell’s Experion platform. Developing control strategies with CAB functionality delivers the following benefits:CAB Developer provides a modern and comprehensive  programminglanguage that supports complex calculations
 Decreaseproduction costs and increase yields bybut requires little training. Control engineers can take implementing complex calculations and tighteradvantage of the Microsoft.NET platform and Visual control. Basic.NETprogramming language, widely used among program developers. This ensures a faster learning curve
engineering and maintenance costs with an Reduce with easy program maintenance. In addition, it’s object efficient and simple programming language oriented environment delivers performance and optimization accessed through an integrated environment. benefits.
errors and rework with a flexible and Minimize powerful execution environment that includes Building a CAB Block is a simple four step process: advanced debug capability, builtin functions, and 1. Definethe custom parameter the ability to reuse blocks. 2. Writethe code
 Preventcontrol execution disasters and avoid accidental programming mistakes with integrated3. Buildthe CAB block type from the code security features and a controlled programming 4. Createa CAB instance from the CAB block type and environment. reuse as often as needed.

Experion Custom Algorithm Block Product Information Note

The tools facilitating these steps are integrated within the development environment, ensuring an efficient and quick process. A single Experion tool environment transports data between Microsoft applications, such as Excel, and the CAB environment, improving easeofuse and development efficiency.

New CAB custom libraries appear with other Experion Control Builder libraries to facilitate easy and fast programming. This provides one integrated engineering environment. As soon as a CAB is saved, it instantly becomes available for use in Control Builder, like any other Function Block in the library. Instantiating and configuring a CAB is the same as any noncustom block for use within Control Builder. You can even export and import CAB types between Experion systems. Using generic CAB blocks reduces engineering time and maintains loop and function block consistency.

Experion’s integrated tool environment includes the CAB Developer and eliminates manual efforts to copy solutions between the development tool and the execution environment.

Powerful Development Features Reduce Engineering and Maintenance Costs

The integrated CAB Developer environment provides many timesaving features. A powerful debugging capabilityallows setting breakpoints, flow control for branch coverage, and changing variable values while stepping through the code, providing greater control of the debug session code. This reduces rework and ensures better quality code the first time a CAB program is deployed onprocess.

Figure 1: CAB Debug Environment

With this functionality, there is no need to manually step through code or insert temporary messages to determine intermediate values. Exception messages are descriptive and shown with line numbers, providing quick navigation to the error location. It is easy to write sophisticated, high quality control programs with the rich capability and debugging features of the CAB Developer.

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Custom parameter definition in Control Modulesassists in building the system configuration parameters required, resulting in operator and engineering effectiveness. This feature also provides a migration path for the Control Language (CL) custom data segments.

Utilizing Visual Basic syntax, nested loops, and case statements, engineers can program complex logic with less lines of code. This results in optimized code and improves runtime performance.

CAB provides the flexibility to view, validate, review, and edit the configured parameters and program code usingCAB Developers intuitive user interface. CAB prefetches and

Figure 2: CAB Development Environment

poststores data so that many CABs can run in different time slots. This powerful and flexible environment supports a wide range of functionality that allows creating simple function blocks as well as complex applications, such as batch applications. Honeywell’s Batch Digester is an example of a large complex batch program successfully implemented with CABs.

Experion Custom Algorithm Block Product Information Note

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In addition, the following features support an efficient CAB Protects Customer Investments development and user environment: Honeywell’s long tradition of investment protection and deep
The CAB Developer provides automaticCAB type understanding of control system language are reflected in documentation,the CAB design, making it a progressive evolution of theoffering the ability to manage versions, resulting in easy code maintenance. Application Module/Control Language (AM/CL). Protecting a customer’s investment and their value in existing control
The CAB type property windowdisplays strategies is one of the cornerstones of the CAB design. validation information to review the configured Migration capabilities, combined with the integration of TPS parameters and program source code in an intuitive into the Experion architecture, give our customers flexibility user interface from both Control Builder and the to leave AM/CL coexisting with CAB or to migrate to CAB. operator detail display. Engineering tools are embedded with simple utilities, such
Prebuilt function librariesused within CAB as copy & paste, making it easy to migrate to CAB. Developer facilitate faster CAB programming and Commercialofftheshelf tools and environments are help maintain clean code to reduce the enhanced to provide a powerful language environment that development cycle. supports CL migration within a modern development
Auto colorcoding enhances readability andenvironment. The sample high level table below maps maintenance of custom programs.This providesreferences between AM/CL and CAB. better control over the programs when Sample high level mapping of AM/CL references to CAB. modifications are necessary or when different AM/CL ReferenceCAB Associated Reference engineers are maintaining the same code. Parameter_List Parameter_References Custom Data SegmentParameter references and Custom Integrated Security Features Prevent Engineering and Data Block Control Errors CL BlockCAB Block (Algorithm +parameters)(VB.NET Algorithm +parameters) Using CAB types provides security benefits to a plant or mill. Program (Syntax, Logic)More Optimized and usually Configurable alarms (errors, read/write violations, and block reduced # of lines of code terminations) help detect problems early and prevent Program CommentsMore readable and maintainable disasters. There are several integrated features that prevent development or execution errors, for example:
 Honeywell CAB Developer’s rich development environment, paired with has integrated the VB.Net compiler with a process control compiler check function called its ease of use, supports migrating your intellectual property Function Limiter. This prevents the use of any in complex custom control programs to Experion. This is true VB.Net constructs that could be adverseto a for both legacy Honeywell programs and thirdparty control process control mission (i.e. a message box that platforms. stops all processes until a user response is Honeywell also offers engineering services that utilize Six received). Sigma processes and unparalled expertise to deliver a faster
engineering  Thesystem terminates the block automatically on cycleand accurate database and control memory violations, preventing crashing the language migration. controller environment. Experion supports a gradual migration path so CL customers
can migrate at their own pace. Honeywell’s CAB technology system terminates the block automatically if The excessive execution is detected, preventing is an integral part of the Experion Process Knowledge possible disasters caused by locking up the System, offering a natural evolution of existing advanced controller environment. control strategies to an open and scalable control platform.

Experion Custom Algorithm Block Product Information Note

For More Information Learn more about how Honeywell’s Custom Algorithm Block technology can improve control efficiency while reducing engineering costs, visit our website or contact your Honeywell account manager. Honeywell Process Solutions 2500 Union Hills Dr. Phoenix, AZ 85027 Tel: [phone] www.honeywell.com/ps

PN05018ENG May 2005 Printed in USA © 2005 Honeywell International Inc.

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