isa-5.3-1983 graphic symbols for distributed controlshared display instrumentation, logic and computer systems

1、Graphic Symbols for Distributed Control/Shared Display Instrumentation, Logic and Computer SystemsApproved 30 June 1982ISA–5.3–1983Formerly ISA–S5.3–1983S T A N D A R DISA The Instrumentation, Systems, and Automation S

2、ociety –TMISA-S5.3-1983 3PrefaceThis preface is included for informational purposes and is not part of ISA-5.3-1983.This Standard has been prepared as a part of the service of ISA toward a goal of uniformity in the fiel

3、d of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Towards this end, the Society welcomes all comments and criticisms and asks that they be addresse

4、d to the Secretary, Standards and Practices Board, ISA, 67 Alexander Drive, P .O. Box 12277, Research Triangle Park, North Carolina 27709, telephone 919- 549-8411, e-mail: standards@isa.org.The ISA Standards and Practic

5、es Department is aware of the growing need for attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Departm

6、ent is further aware of the benefits to USA users of ISA Standards of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other countries. Towards this e

7、nd this Department will endeavor to introduce SI and SI-acceptable metric units in all new and revised standards to the greatest extent possible. The Metric Practice Guide, which has been published by the American So

8、ciety for Testing and Materials as ANSI designation Z210.1 (ASTM E380-76. IEEE Std. 268-1975), and future revisions, will be the reference guide for definitions, symbols, abbreviations, and conversion factors.The syst

9、ems referenced in this Standard are based on advances in control systems technology since the publication of ISA-S5.1, “Instrumentation Symbols and Identification.“ During recent years, technology has evolved in terms

10、of microprocessor-based systems presently manufactured by many companies as “Distributed Control Systems.“These systems may include components identified as “computers“ as distinct from the integral processor, which de

11、rives the various functions of the system. The computer component may be integrated into the overall system, via the communication link, or it may be a stand-alone computer.In attempting to implement these systems, th

12、e need for supplementary symbolism has become apparent.The symbols defined in ISA-S5.3 are intended to complement those of ISA-S5.1, “Instrumentation Symbols and Identification,“ for use on flow diagrams. In this way,

13、 the integration of distributed controllers and process computers into the more traditional instrument systems — analog, binary, and digital — can be depicted clearly on flow diagrams and other documents to give an ov

14、erall and comprehensive picture of how process variables are measured and controlled.Distributed control systems appear to be similar to each other; however, they are so diverse in philosophy that there must be a gener

15、ic way to document their application.The second printing of ISA-S5.3, dated April 1983, was published to correct errors in the original 1982 edition. The definition for communication link, Section 3, has been corrected

16、 and an omitted abbreviation, C.R.T., added. Minor clarifications were also made to the Appendix A artwork.The ISA Standards Committee on Graphic Symbols for Distributed Control/Shared Display Instrumentation, Logic