International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*MEX~YHAPO~HAR OPI-AHM3ALUdR l-l0 CTAHAAPTbl3ALWl.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Industrial process measurement control functions and
instrumentation - Symbolic representation -
Part 4: Basic symbols for process computer, interface,
and shared display/control functions
Fonctions de rkgulation, de mesure et d’automatisme des processus industriels - Reprhsenta tion s ymbolique -
Partie 4: S ymboles de base pour la reprhsentation des fonctions calculateur
First edition - 1985-08-15
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UDC 744.43 : 62-52 : 003.62 Ref. No. IS0 3511/4-1985 (E)
Descriptors : technical drawing, graphic symbols, control functions, measuring instruments, control devices, adjusting systems.
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Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
International Standard IS0 3511/4 was prepared by Technical Committee ISO/TC 10,
Technical drawings.
This part of IS0 3511 was developed by sub-committee 3, Graphical symbols for
instrumentation. The symbols are intended to be used to represent functions and, in
special cases, equipment on technical drawings such as schematic diagrams or process
flow-diagrams. However, this field of engineering is closely related to electrical
instrumentation dealt with by IEWTC 65 or in part by IEWSC 3A. For this reason there
has been close coordination in a joint working group and the results were accepted by
members of IS0 and IEC.
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0 International Organization for Standardization, 1985
Printed in Switzerland
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INTERNATIONAL STANDARD ISO3511/4-1985 (Eb
Industrial process measurement control functions and
instrumentation - Symbolic representation -
Part 4: Basic symbols for process computer, interface,
and shared display/control functions
0 Introduction They are intended to provide a means of illustrating process
computer and/or shared display/control functions in the field
This International Standard has been devised to provide a of process measurement and control and may be used with the
universal means of communication between the various in- symbols of IS0 3511 /l and IS0 3511/2. They will enable users
terests involved in the design, manufacture, installation and to show and identify in simple form the functions of instru-
operation of measurement and control equipment used in the ments, the process computer, and shared display/control func-
process industries. tions, or any combination of these.
Requirements within the industries vary considerably; in It is permissible to use the basic symbol for computer-based
recognition of this, this International Standard is presented in functions (see 3.1) throughout for any software-based digital
four parts as follows: system. This is not intended to preclude the use of the basic
symbol for shared display/control functions (see 3.2) if the user
considers this to be appropriate.
Part 1 : Basic requirements (directed towards the needs of
those employing comparatively simple measurement and
The symbols are intentionally limited to identification on pro-
control means).
cess flow diagrams, piping and instrument diagrams, etc. and
do not provide means of illustrating specific instruments or
Part 2: Extension of basic requirements. parts thereof.
Part 3: Detailed symbols for instrument interconnection The letter code for function identification shall be taken from
diagrams. table 1 of IS0 3511/l and IS0 3511/2.
Part 4: Basic symbols for process computer, interface func- The application methods are shown in the examples.
tions, and shared display/control functions.
These parts together are intended to
2 Definitions
a) meet the requirements of those who, possibly employ-
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ing more sophisticated measurement and control means, For the purposes of this part of IS0 3511, the following defini-
may wish to depict such aspects as the measurement tions and the definitions given in IS0 3511 /l and IS0 3511/2
techniques embodied in a particular instrument, or the apply n
means - hydraulic, pneumatic, electrical, mechanical -
used for its actuation;
2.1 programmable: Term indicating the capability of the
system to accept instructions in computer language given by
b) provide standard symbolic representation for process
the user for performing control strategies or complex functions.
measurement control functions and instrumentation. These
symbols are not intended to replace graphical symbols for
electrical equipment as contained in IEC Publication 617, 2.2 configurable: Term indicating the capability of the
Graphical symbols for diagrams. system to allow the user to select, from pre-programmed func-
tions (modular software units), those which are necessary to
accomplish a control strategy or other complex functions,
1 Scope and field of application without the use of computer language.
The symbols established in this part of IS0 3511 have been 2.3 process computer: Programmable device which
developed to be used in conjunction with the symbols given in operates in real time on process data, on-line (primarily sensor-
IS0 3511/l and IS0 3511/2 and shall be considered as sup- based), to perform user specifiable supervision and/or control
plementary. functions.
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IS0 3511/4-1985 (E)
2.4 shared display/shared control system:System in - a letter code in accordance with IS0 3511/l and
which shared functions, such as display, control and com- IS0 3511/2 denoting the process computer functions.
munications, are shared in time, i.e. “time-shared” functions.
These functions are generally accomplished by devices contain- If required, a number may be included to make identification
ing pre-programmed algorithms which are user accessible, con- easier.
figurable and connectable to perform a given control strategy
or function. If only computer functions are provided, the basic symbol
may be used [see figure lb)].
2.5 distributed control system (DCS) : System for process
The basic symbol is usually applied in conjunction with the
control purposes which, while being functionally integrated,
basic symbols of IS0 3511 /l and IS0 3511/2 showing
consists of sub-systems which may be physically separated and
measured process variables or actuated correcting unit [see
remotely located from one another. These sub-systems are nor-
figure 14.
mally connected by a communication link (e.g. data bus).
Symbols which touch each other imply communication be-
2.6 software link: Interconnection of system functions via tween functions.
keyboard or program instructions (soft wiring as opposed to
hard wiring). NOTES
1 An acceptable alternative symbol, used by some countries, is the
thin line half-circle. Several examples of this usage are shown for
3 Basic symbols reference in clause 4.
2 The single horizontal line (see IS0 3511 /I) should be used to in-
3.1 Basic symbol for computer-based functions dicate the existence of operator interface in the control room.
The symbol comprises 3 The double horizontal line (see IS0 3511/Z) should be used to in-
dicate accessibility at a local panel.
- a thin line hexagon of approximately 10 mm width be- 4 This symbol is intended to represent computer and interface func-
tween two parallel sides [see figure la)]; tions performed by a programmable device.
0
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a) Basic symbol b) Symbol for pro cl SY mbol in connection
computer only instruments
Figure 1
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ISO 3511-4:1985 Industrial process measurement control
functions and instrumentation - Symbolic representation - Part
4: Basic symbols for process computer, interface, and shared
display/control functions
This is a free 4 page sample. Access the full version online.
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