Terminologia y simbolos de control de igenieria

YTechnical Information

Terminology and Symbols in Control Engineering

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Part 1 Fundamentals

Technical Information
Part 1: Part 2: Part 3: Part 4: Part 5: Part 6: Fundamentals Self-operated Regulators Control Valves Communication Building Automation Process Automation

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Part 1 ⋅ L101 EN

Terminology and Symbols in Control Engineering
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Terminology in Control Engineering . . . . . . . . . . . . . . . . . . 6 Open loop control . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Closed loop control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Control loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Abbreviations of variables relating to closedloop control. . . . . . . . . 10 Symbols in Control Engineering . . . . . . . . . . . . . . . . . . . 12 Signal flow diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Device-related representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Instrumentation and control tags . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Control Systems andStructures . . . . . . . . . . . . . . . . . . . . 22 Fixed set point control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Follow-up control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Cascade control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Ratio control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 24 Appendix A1: Additional Literature . . . . . . . . . . . . . . . . . . 26

CONTENTS
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Blocks and lines of action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

SAMSON AG ⋅ 00/03

Fundamentals ⋅ Terminology and Symbols in Control Engineering

Preface

The technical informations presented in this document are based on definitions according toDIN, the German organization of standardization (Deutsches Institut für Normung). Continuous efforts are being made to determine international definitions in order to achieve an increasing similarity in the terminology used. Nevertheless, differences in designations and representations do exist in international use. Literature presented at the end of this document includes international standardsand publications relating to DIN standards, or being derived from them. Representations and text sections referring to DIN are often cited in short form, summarizing the contents. The precise facts must always be read - also because of possible extensions or amendments - in the current edition of the respective standard.

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SAMSON AG ⋅ V74/ DKE

Part 1 ⋅ L101 EN

Introduction
Planning,design and start-up of process control systems require clear and unambiguous communication between all parts involved. To ensure this, we need a clear definition of the terms used and – as far as the documentation is concerned – standardized graphical symbols. These symbols help us represent control systems or measurement and control tasks as well as their device-related solution in a simple andclear manner.

SAMSON AG ⋅ 00/03

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Fundamentals ⋅ Terminology and Symbols in Control Engineering

Terminology in Control Engineering
To maintain a physical quantity, such as pressure, flow or temperature at a desired level during a technical process, this quantity can be controlled either by means of open loop control or closed loop control. Open loop control In an open loop control...