ISO 16484-2:2004

INTERNATIONAL ISO
STANDARD 16484-2
First edition
2004-08-01
Building automation and control systems
(BACS) —
Part 2:
Hardware
Systèmes de gestion technique du bâtiment —
Partie 2: Équipement
Reference number
©
ISO 2004
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ii © ISO 2004 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16484-2 was prepared by the European Committee for Standardization (CEN) in collaboration with
Technical Committee ISO/TC 205, Building environment design, in accordance with the Agreement on
technical cooperation between ISO and CEN (Vienna Agreement).
Throughout the text of this document, read ".this European Standard." to mean ".this International
Standard.".
ISO 16484 consists of the following parts, under the general title Building automation and control systems
(BACS):
— Part 1: Overview and definitions
— Part 2: Hardware
— Part 3: Functions
— Part 4: Applications
— Part 5: Data communication protocol
— Part 6: Data communication — Conformance testing
— Part 7: Project implementation

Contents                                                       Page
Foreword.v
Introduction.vi
1 Scope .1
2 Normative references.1
3 Terms and definitions .2
4 Abbreviations, acronyms and symbols, .27
5 Requirements.29
5.1 BACS components .29
5.1.1 Hardware components and system functionality .29
5.1.2 System configuration.29
5.1.3 Basic hardware performance criteria .30
5.2 Management devices.30
5.2.1 General .30
5.2.2 Data processing device, server station.31
5.2.3 Peripherals .31
5.2.4 Interfaces.33
5.2.5 Alarm indication and annunciation devices .34
5.3 Control devices.34
5.3.1 General .34
5.3.2 Controller.36
5.3.3 Application specific controller.42
5.4 Field devices .43
5.4.1 General .43
5.4.2 Coupling module .43
5.4.3 Local override/indication device.44
5.4.4 Sensors.45
5.4.5 Actuators.47
5.4.6 Room device .50
5.5 Cabling.50
5.6 System communications .51
5.6.1 General .51
5.6.2 Interconnection of devices within networks.53
5.6.3 Interconnection of devices between networks.53
5.6.4 Communications protocol.54
5.7 Engineering/commissioning tools.54
5.7.1 General .54
5.7.2 Engineering tools .54
5.7.3 Commissioning tools .54
Annex A (informative) General safety requirements and environmental conditions.56
A.1 General .56
A.2 National annexes .56
Annex ZA (normative)  Normative references to international publications with their corresponding
European publications.57
Bibliography.58

iv © ISO 2004 – All rights reserved

Foreword
This document (EN ISO 16484-2:2004) has been prepared by CEN /TC 247, "Building Automation, Controls and
Building Management", the secretariat of which is held by the SNV, in collaboration with ISO/TC 205 "Building
Environment Design".
This document has to be implemented at national level, either by publication of an identical text or by
endorsement, by February 2005, and conflicting national standards have to be withdrawn by February 2005.
The EN ISO 16484-2 is part of the EN ISO 16484 series of International Standards under the general title
Building Automation and Control Systems (BACS), which will comprise the following parts:
Part 1: Overview and Vocabulary
Part 2: Hardware
Part 3: Functions
Part 4: Applications
Part 5: Data communication - Protocol
Part 6: Data communication - Conformance testing
Part 7: Project specification and implementation

In this standard, Annex A: General safety requirements and environmental conditions and the Bibliography are
both informative.
The Annex ZA Normative references to international publications with the corresponding European publications,
is normative.
NOTE  National annexes may contain information provided for easier implementation, e.g. an alphabetical index or national
footnotes.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg,
Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
Kingdom
Introduction
This series of standards is intended for design of new buildings and retrofit of existing buildings for an
acceptable indoor environment, practical energy conservation and efficiency.
The application of this series of standards for BACS is envisaged as follows:
- the environmental design for all building types requires complex methods for automation and control. The
functional integration of services other than HVAC e.g. lighting and electric power distribution control, security
control, transportation, maintenance management or facilities management is a general task for all parties
employed to develop an integrated multi-application system. This integration allows the user to take advantage
of synergies between the different applications. This standard will give guidance to architects, consultants and
contractors as well as to users on how to share such resources,
- the innovation cycles between devices, systems and networks vary. To make it possible to add and to change
existing devices, and extend the building automation and control network, several interfaces both proprietary and
standardized are defined between the BACS network and the other systems. A manufacturer can design a
product, both to meet his specific marketing objectives and to give the option to integrate that special device into
a multi-application BACS. Interfaces are also defined in appropriate parts of this standard along with the
necessary communications protocol and conformance test required to support the inter-working of devices,
- a manufacturer, a systems house, or an electrical or mechanical contractor can assemble an implementation of
a building automation and control system,
- the application of this standard is not to standardize the hardware and software design or the architecture of a
System, but to define the process for the creation of project specifications, where functionality and the quality of
the solution are clearly defined.
The purpose of this series of standards is intended for use by those involved in the design, manufacture,
engineering, installation, commissioning, operational maintenance and training of BACS when contracted, i.e.:

 as a guide to the terminology of the building automation and control trade. Unambiguous terminology is
required for a complete and accurate conveyance of the intent and details of this standard;
 in product development, to avoid unnecessary duplication of function or terminology, but should not place a
restraint on the evolution of new products, systems or applications;
 as a basis for interfacing products and systems. In order to interoperate, the elements of a BACS require a
unified data communication protocol and information model;
 as a basis for drawing up a project specification for the procurement of building automation and control
products for systems suppliers and customers;
 as a code of practice for expertly commissioning prior to handover of a system;
 by educational establishments wishing to train people in the field of building automation and control systems.
This entire series of BACS standards consists of the following contents:
Part 1: Overview and definitions (in preparation)
Part 1 of this standard describes the objectives and interrelationships of all parts of this standard. It provides an
overview and detailed information about the structure of the related series of standards for the BACS industry.
This part of the standard provides also the vocabulary with terms and definitions for the understanding of the
entire series of this standard and it contains a translation of the main terms in English, French, Russian, and
German in an informative annex.
vi © ISO 2004 – All rights reserved

This ongoing work is coordinated at expert level with standards work from ISO/TC 205 WG 3 and CEN/TC 247/
WG 3, WG 4, WG 5 and WG 6.
Part 2: Hardware (refer to the scope of this part)
Part 3: Functions
Part 3 of this standard specifies the requirements for the overall functionality and engineering services to
achieve building automation and control systems. It defines terms, which shall be used for specifications and it
gives guidelines for the functional documentation of project/application specific systems. It provides a template
for documentation of plant/application specific functions, called BACS function list in annex A.
The informative function block examples explain a method to display the referenced functions in system
documentation; they do not standardize the method for programming functions and applications.
This Part 3 of the standard covers the following:
Requirements and definitions regarding BACS and application software, generic functions for plant/project
specific applications and engineering functions for building controls and operations. It provides communication
functions for the integration of other dedicated special system processes. The functional requirements in this
part of the standard are subdivided as follows:
 System management and application software:
describes the requirements for plant independent system and human system interface programs related to a
project, including the operating system. This standard does not dedicate the following system functionality to
any particular hardware, e.g.:
 system diagnostics, watchdog, redundancy, time keeping, access control, log lists;
 point identification, event message handling, print control;
 database, statistics, data archiving, remote access;
 system communications.
 Human system interface (HSI), point information presentation, graphics, alarms, time scheduling
 Engineering process and tool software:
describes the requirements for configuring of the hardware and control strategies, the system management
and the commissioning process.
 BACS application processing programs and plant/application specific functions:
describes the requirements for plant, application and / or project specific functions and a method for the
documentation of a project. The functions are subdivided into the following types:
 input and output functions;
 processing functions;
 management functions and required communications;
 operator functions.
Part 3 defines a method for creating the procurement specifications containing all essential elements required for
the operational functioning of a BACS. The successful installation and operation of a BACS requires that its
procurement be based on a complete specification with accurately defined functions.
The standard provides a template called the ‘BACS function list’ that can be found in annex A (normative). Its
purpose is to determine and document the options for plant / application specific functionality. Further
explanations can be given in form of plant/control descriptions, control flow chart diagrams, and plant/control
schematics. Examples are given in annex B (informative). The exact specifications will be project-specific.
Information about the standardized functions is given in the form of informative examples as function-blocks,
textual, and graphical descriptions in 5.5.
It is recognized, that functions can be described and implemented in many different ways, depending on:
 climatic differences;
 cultural and regional differences;
 national regulations.
Part 4: Applications
Part 4 of this standard specifies the requirements for specific communicating applications/devices, e.g. for
general room automation and for sophisticated optimization of controls for heating, fan coil and induction units,
CAV, VAV and radiant cooling.
This work will be coordinated at expert level with standards work from ISO/TC 205 WG 3 and CEN/TC 247.
Part 5: Data Communication – Protocol
Part 5 of this standard specifies data communication services and objects for computer equipment and
controllers used for monitoring and control of HVAC&R and other systems of building services.
This protocol provides a comprehensive set of objects for conveying encoded binary, analog, and alphanumeric
data between devices including, but not limited to:
 input measuring: analog input object;
 output positioning/set-point: analog output object;
 binary input counting;
 input state: binary input object, multi-state input;
 output switching: binary output object, multi-state output;
 values: analog value, binary value, multi-state value, accumulated value, averaging object, trend log object;
 text string;
 schedule information;
 alarm and event information;
 files; and
 control programs and parameters respectively.
This protocol models each building automation and control system as a collection of data structures called
objects, the properties of which represent various aspects of the hardware, software, and operation of the
device. These objects provide a means of identifying and accessing information without requiring knowledge of
the details of the device's internal design or configuration.
An overview of possible integration with other systems in buildings, e.g. fire, security, access control, maintenance
and facilities management, is shown in Figure 1 of Part 2 of this standard.
viii © ISO 2004 – All rights reserved

Part 6: Data Communication – Conformance testing
Part 6 of the standard specifies the technical requirements of the conformance test suite and the methods for
testing the products for the conformance with the protocol. It provides a comprehensive set of procedures for
verifying the correct implementation of each capability claimed on a BACS network protocol implementation
conformance statement (PICS) including:
a) support of each claimed BACS network service, either as an client (initiator), server (executor), or both;
b) support of each claimed BACS network object-type, including both required properties and each claimed
optional property;
c) support of the BACS network layer protocol;
d) support of each claimed data link option, and
e) support of all claimed special functionality.
Part 7: Project specification and implementation
Part 7 of this standard specifies methods for project specification and implementation of BACS and for
integration of other systems into the BACS. This standard defines terms to be used for project specifications and
gives guidelines for integration of other systems.

a) Project specification and implementation:
This clause of the standard describes the procedures (codes of practice) required for the following:
 project specification;
These procedures also contain an example for a plant/system/customer premises wide unique
structured addressing system for data point identification;
 engineering;
 installation;
 project handover.
b) System integration:
This clause of the standard describes the special requirements/procedures for the integration and
implementation of intersystem communication with foreign systems and the interconnection of other
units/devices with integrated communications interfaces, e.g. chillers, elevators.
1 Scope
This part of the standard specifies the requirements for the hardware to perform the tasks within a BACS. It
provides the terms, definitions, and abbreviations for the understanding of Part 2 and Part 3.
Part 2 relates only to physical items/devices, i.e.:
 operator stations and other human system interface devices;
 devices for management functions;
 control devices, automation stations and application specific controllers;
 field devices and their interfaces;
 cabling and interconnection of devices;
 engineering and commissioning tools.
This part of this standard shows a generic system model to which all-different types of BACS and their
interconnections (BACS network) can fit. A graphical concept of the BACS network in terms of LAN and inter-
network topology will be provided in Part 5 of this standard.
National annexes:
National annexes may specify the local requirements of physical and electrical characteristics, the verifications
for BACS devices and equipment, and the code of practice for the physical installation of systems. The annexes
shall refer to the regional implementations of the relevant IEC standards.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
IEC 60050-351 International Electrotechnical Vocabulary — Part 351: Automatic control
Degrees of protection provided by enclosures (IP code)
IEC 60529:1989
+ AMD1:1999
Insulation coordination for equipment within low-voltage systems — Part 1:
IEC 60664-1:1992
+AMD1:2000 Principles, requirements and tests
+AMD2:2002
IEC 60715:1981 Dimensions of low-voltage switchgear and controlgear — Standardized mounting on
rails for mechanical support of electrical devices in switchgear and controlgear
+AMD1:1995
installations
Programmable controllers — Part 3: Programming languages
IEC 61131-3:2003
ISO/IEC 2382-1:1993 Information technology — Vocabulary — Part 1: Fundamental terms
ISO/IEC 2382-18:1999 Information technology — Vocabulary — Part 18: Distributed data processing
ISO/IEC 2382-26:1993 Information technology — Vocabulary — Part 26: Open Systems Interconnection
Information technology — Open Systems Interconnection — Basic reference model —
ISO/IEC 7498-1:1994
Part 1: The basic model
Information technology — Open Distributed Processing — Reference model — Part 2:
ISO/IEC 10746-2:1998
Foundations
Standardization and related activities — General vocabulary
ISO/IEC Guide 2:1996
3 Terms and definitions
This clause presents the vocabulary used in this Part 2 and Part 3 of the standard for BACS.
The terms and definitions listed in this standard but defined by other relevant ISO/IEC International Standards are
repeated below for convenience in most cases.
NOTE  Other language versions may contain an alphabetical index in National Annexes.
For the purposes of this standard, the following terms and definitions apply.
3.1
3-point control
control function with a three-position output that can assume only three discrete values: zero and two values with
opposite signs. These output values are used to position with two binary signals providing three control states

EXAMPLE
a) opening, stopped, closing;
b) more, neutral, less;
c) heating, neutral, cooling.
3.2
access control
method for determining or restricting access to system and network resources
[Part 5, 3.2.1]
cf. access control system (3.3)

NOTE 1  Also refer to security and operator authentication.

NOTE 2  Data privacy protection is the framework conditions protecting personal data from being used by any one other
than the owner (regulated by national law).

NOTE 3  Data security is the framework conditions to protect data from direct or indirect manipulation or unauthorized use.
Data manipulation includes loss of data, destruction or falsification of data.

NOTE 4  Data security means are the measures and equipment to secure and maintain the safety of data.
3.3
access control system
1) a dedicated special system for security
cf. access control (3.2)
2) automatic checking of access rights under organizational measures and barrier/door control for
buildings/rooms, including registration of events

NOTE  An access control system belongs to security systems.
3.4
acknowledge
the recognition and/or registration of an event (e.g. alarm) by an operator

NOTE  An acknowledgement can be invoked by an operator using a physical device, or by using a human system interface
e.g. selecting an Icon on a VDU.
3.5
acknowledgement
a function that allows a destination node to inform a sending node of the receipt of a
protocol-data-unit
[ISO/IEC 7498-1:1994]
2 © ISO 2004 – All rights reserved

3.6
actuator
field device (3.80) that interfaces to control a plant process, operated electrically, pneumatically, or
hydraulically. It influences the mass flow or energy flow
c.f. positioning actuator (3.153)

NOTE 1  A control valve is the combination of a valve with its operating element.

NOTE 2  A regulating element (functional unit), or a final controlling element (physical unit) [IEV 351], i.e. a damper, a valve
is often referred to as positioning actuator (3.1.5.3).
3.7
actuator
bus communications output device (analog or binary), e.g. to control a load, a contactor, or a positioner
c.f. switched actuator (3.185)

NOTE 1  A binary actuator is sometimes also referred to as switched actuator (on/off type).
3.8
address
unique object identifier and/or device identifier within a system or combined systems
1) cf. point address (3.150)
2) cf. user address (3.196)
NOTE 1  In BACS, each data point has an identifier named point address.

NOTE 2  In BACS, each communications object has properties named object identifier and object name.
3.9
addressing system
address scheme
unique structured method for data point identification to address the information provided in BACS, consisting of
a scheme and the semantics of the elements
cf. user address (3.196)
NOTE 1  This scheme can apply throughout a plant, a complete BACS, or the entire customer premises as appropriate.
3.10
alarm
warning of the presence of a hazard to a property or the environment, in security systems also to life

NOTE 1  An annunciation either audible or visual or both that alerts an operator to an abnormal condition, which can require
corrective action.
[Part 5, 3.2.2]
NOTE 2  An abnormal condition detected by a device or controller that implements a rule or logic specifically designed to
look for that condition, e.g. ‘frost alarm’.
3.11
algorithm
1)  calculation that results in an output by evaluating input variable(s)

2)  completely determined finite sequence of instructions by which the values of the output
variables can be calculated from the values of the input variables
[ISO 60050-351]
3.12
alphanumeric
character set, that consists at least of decimal digits and letters

NOTE  It is advisable to specify the extent of the character set in each case.
3.13
analog input/output
part of the hardware pertaining to a control device for measuring or positioning
3.14
analog value
information containing a numerical represented quantity
3.15
application
a set of functions that together form a logical unit supporting a process

NOTE 1  A BACS supports many different applications.

NOTE 2  A set of a user’s information processing requirements.
[ISO 8649], [Part 5, 3.1.2]
3.16
application object
object located within the BACS device’s application process
cf. object type (3.133)
NOTE  See object (3.132).
3.17
application specific controller
ASC
controller
customized device fulfilling the requirements of a specified application

NOTE  In BACS, a controller is any device capable of controlling/automation and possibly monitoring other devices and units.
3.18
architecture
structure and means by which components and devices of a system are connected to
intercommunicate
3.19
automation
SEE control (3.51)
NOTE  Also refer to processing functions (3.155).
3.20
automation network (US)
AN
control network (GB)
CN
connections between controllers, operator stations / panels, programming units, data interface units, and data
processing devices (e.g. server stations)

NOTE  A schematic diagram is shown in figure 1.
3.21
backup
1)  process to copy/export data to the data storage of an external backup device to retrieve
and restore this data in case of a storage fault. The copy is referred to as backup copy

2)  supporting services
3.22
backup power operation
operating mode using reserve power supply systems for building operation
4 © ISO 2004 – All rights reserved

3.23
BACS application program
software to perform one or more tasks of a BACS
3.24
BACS function list
BACS FL
information list (deprecated)
Spreadsheet list for documentation and summing up BACS functions, defined in Part 3 of this standard

NOTE  A BACS points list (BACS PL) in some countries referes to the physical I/O only.
3.25
BACS network
Building automation and control system network to exchange information between digital (binary), analog, and
other communication objects in different devices.
3.26
binary (signal)
signal that represents the state (e.g., on/off) of a single binary coded digital information (logic 0 and I). It applies
to input and output functions of a BACS

NOTE 1  In BACS, a digital value is a variable that represents the value of digitally coded analog or binary information. It
applies to shared/network data points.

NOTE 2  Devices with a number of binary inputs/outputs are often referred to as digital (3.65).
3.27
binary input/output
hardware pertaining to control devices for state processing or switching

NOTE  The function is referred to as binary input state and output switching.
3.28
bridge
device that connects two or more segments of a network at the physical and data link layers of the ISO-OSI
basic reference model
NOTE  This device can also perform message filtering based on MAC layer addresses.
[Part 5, 3.2.6]
3.29
building
large volume individual fixed structure other than industrial structures, i.e. commercial, industrial, or commercial
residential premises
cf. house (3.94)
NOTE  BACS can be employed also for other structures, as e.g. house, tunnel, railway, ship.
3.30
building automation and control
BAC
description for products, software, and engineering services for automatic controls, monitoring and optimization,
human intervention, and management to achieve energy – efficient, economical, and safe operation of building
services equipment
NOTE  The trade designation and the industry branch are also referred to as building automation and/or building control.
3.31
building automation and control system
BACS
system, comprising all products and engineering services for automatic controls (including interlocks), monitoring,
optimization, for operation, human intervention, and management to achieve energy – efficient, economical, and
safe operation of building services

NOTE 1  The use of the word ‘control’ does not imply that the system/device is restricted to control functions. Processing of
data and information is possible.

NOTE 2  If a building control system, building management system, or building energy management system complies with
the requirements of the EN ISO 16484 standard series, it should be designated as a building automation and control system
(BACS).
3.32
building management
BM
all services related to the operation and management of buildings including structural and technical properties
based on integral strategies. BM is structured in:
- technical building management (TBM);
- infrastructural building management;
- commercial building management;
There are interfaces to area and facility management (3.76)

cf. technical building management (3.188)

NOTE  A BACS is the essential tool for TBM.
3.33
building services
BS
utilities and installations supplied and distributed within a building such as electricity, gas, heating, water, and
communications
3.34
bus
communication medium and method between two or more devices with interface for serial data transfer

NOTE 1  A line-form network topology often is referred to simply as a bus.

NOTE 2  A bus is also called a trunk in the US.
3.35
cabling
system of cables and connecting hardware that supports the connection of BACS and other equipment
3.36
cascade control
the output signal or value of a master control loop is used as set-point input to the slave control loop(s)
[derived from IEC 60050-351]
3.37
change of state
COS
event that occurs when a measured or calculated Boolean or discrete enumerated value changes
cf. change of value (3.38)
3.38
change of value
COV
an event that occurs when a measured or calculated analog value changes by a predefined amount
cf. change of state (3.37)
3.39
class
a category or rank attributed to entities having the same function as their use but are subject to quality demands

NOTE  The entity is the item under consideration defined according to function and scope.
6 © ISO 2004 – All rights reserved

3.40
client
a system or device that uses another device for a particular purpose via a service request instance. A client
requests a service from a server
[Part 5, 3.2.10]
NOTE  The customer (landlord) also is referred to as a client.
3.41
closed loop control
system where the output acts upon the process in such a way as to reduce the difference between the
measured value and the desired set-point value to zero
cf. interlocks (3.105), open loop control (3.137)

NOTE  The control action describes the control algorithm (i.e. proportional, integral, derivative) as a relationship between the
input signal and the output signal of a control function.
3.42
commissioning
the project and system-specific process of calibrating field devices, testing data points, parameters, functions,
and system software — as part of the engineering services according to 3.71 — for the various functional
elements of a BACS application

NOTE 1  To take out of commission/to commission: To put a system out of service/into service for a undefined time.

NOTE 2  Commissioning electrical switchgear and control gear is referred to as putting into operation or service.

NOTE 3  For automation and IT systems and mechanical plants, commissioning is also referred to as taking into service,
system startup, startup procedure.

NOTE 4  Commissioning reports are proof for the completeness of tasks and work.
3.43
communications
the transfer of information, in accordance with pre-established protocols
3.44
communications interface
the specification of physical and electrical requirements for the connection components of communicating
products
3.45
compatibility
capability of devices of different types and from different manufacturers to operate in a specific network under
the same conditions and rules
[ISO/IEC 2382-1:1993]
NOTE 1  See Annex A of this standard for electromagnetic compatibility/interference according to 3.70.

NOTE 2  Also see interoperability in 3.106.
3.46
compliance
adherence to the requirements of a standard or the necessary consistency between the individual standards
within a family of standards
[ISO/IEC 10746-2]
3.47
configuration
configuring
1)  site-specific information related to physical and functional units, entered during system engineering
that generally does not change once the system is functioning. The result is the system configuration.

2)  host and target computers, any operating system(s) and software used to operate a processor

NOTE  IT refers to devices/systems of information technology providing services at their interfaces.
3.48
confirmation
a representation of an interaction in which a performing function confirms the completion of some procedure
previously invoked
1) cf. feedback (variable), checkback (signal) (3.79)
2) cf. response (3.171)
3.49
conformance
conformity
fulfillment of specified conformance requirements by a product, protocol, process, or service. If an incorporated
system meets the required specification, this is termed conformance (conformity)
[ISO/IEC TR 13233 and ISO Guide 2]
3.50
conformity
SEE conformance (3.49)
3.51
control
purposeful action on or in a process to meet specified objectives
[ISO 60050-351]
cf. automation (3.19)
automatic closed-loop control (3.41) and open-loop control (3.137), interlocks (3.105), optimization
and monitoring (3.124), as well as operating of one or more physical values and states for operation of
building services (3.33)
cf.  building automation and control (3.30)

NOTE 1  The term control often is used not only for the process in a control system, it is also used for the system (3.187)
itself that performs the control functions (3.53).

NOTE 2  To automate employs means to enable self-acting functions in a system, whereas the term automation depicts the
ready to use state.
[Derived from ISO 60050-351].
NOTE 3  An automaton is a self-acting artificial system, the behavior of which is governed either in a step-wise manner by
given decision rules or continuously by defined relations and the output variables of which are created from its input and state
variables
[ISO 60050-351]
NOTE 4  Control of an operation by human intervention is referred to as manual control.
[ISO 5598, IEC 60050-351]
NOTE 5
The functional areas in control technology differ in the French and German language as follows:
a) (en) closed loop control,
( fr ) regulation en boucle fermee
(de) Regeln,
b) (en) open loop control / positioning,
( fr ) regulation en boucle ouverte
(de) Stellen (analog Steuern / Stellen),
c) (en) interlocks
( fr ) Asservissements
(de) Steuern (Steuerlogik, Verknüpfung),
d) (en) 〈BACS〉 control (automation USA),
( fr ) 〈GTB〉 Surveillance (automation),
(de) 〈GA-System〉 Beherrschen, (Messen, Steuern, Regeln, Leiten).
8 © ISO 2004 – All rights reserved

3.52
control diagram
process flow diagram (deprecated)
piping and instrument diagram (P&ID) (deprecated)
flow diagram representing the procedure, configuration, and function of a plant for building services including the
instrumentation and functions for a BACS
3.53
control function
automatic closed loop (3.41), open loop (3.137) and interlock (3.105) function (3.84) for a process (3.154)
cf. processing function (3.155).
3.54
control strategy
diagram and/or software that represents the functional requirements of a BACS application
3.55
controller
automation station
outstation (obsolete)
device for regulation and/or logic control as well as monitoring and processing of information, e.g. temperature,
humidity, pressure
[Part 5, 3.2.12]
NOTE 1  Digital controller (DDC) can be subdivided into the following types:

1) fixed-function controller
as application-specific controller ASC where the manufacturer supplies one or more fixed control strategies for specific
applications;
2) configu
...