BEMS Terminology
IBEC / terminology (translated by Tamaoki)
GLOSSARY OF BEMS TERMS
May 1992
Institute of Building Energy Conservation
Building Energy and Management System
This glossary of BEMS terms is restricted to the most commonly used terms specifically related to Building Energy and Management systems.
A bibliography is included which IEA Annex 16 Glossary, communication terms, computer terms and control terms where additional terms are defined.
ADAPTIVE CONTROL SYSTEM
A system in which automatic means are used to change the system parameters in a way intended to achieve the best possible performance of the system at all times.
ADAPTIVE PROGRAMME
A control algorithm that has the ability to change its performance characteristic to suit changes in requirements or in the control loop parameters.
ALGORITHM
A finite set of well defined rules or series of instructions or procedural steps for the solution of specific problem in a finite number of steps or the control of particular item of plant.
ANALOGUE SIGNAL INPUT/OUTPUT
Input from a continuously varying signal (e.g., a temperature sensor) and output for a continuously varying signal (e.g., for a water valve).
ANNUNCIATOR
Treatments and processing of alarms.
ALPHANUMERIC CHARACTER SET
The set of characters including A - Z the numerals 0 - 9 and some special characters e.g. (:, -, ). Punctuation marks, control characters. Mathematical symbols and Greek characters may also be considered to be ALPHANUMERIC.
APPLICATION PROGRAM
A program that runs on a computer and performs some function.
ARCHITECTURE
In data communications or building control systems, a definition of components and their relationships within a communications network.
ARCHIVING
Storage of DATA in a retrievable form using a NON-VOLATILE storage media.
AREA MANAGEMENT SYSTEM
A system which centralizes the monitoring, operations, and management of each buildings in area or complex building to achieve more efficient operations.
ARTIFICIAL INTELLIGENCE
The concept that computers can be designed and programmed to assume some of the capabilities associated with human intelligence such as learning, adaptation, self correction and making logical decisions.
AUTHORITY
A setting that indicates the relative effect a compensating sensor input has on the main setpoint (ex. pressed in percent)
AUXILIARY MEMORY or AUXILIARY STORAGE or SECONDARY MEMORY
Another name for backing store.
BACK-BONE BUS
Media that typically passes from the roof of a building to the basement (or around a campus-like architecture) that acts as the central telecommunications media for a network (usually fiber optic cable).
BACK-UP SYSTEM
A building system that provides back up for the either system on system loops normally supported by the system, device, transmission.
BACnet
Building Automation Control network ﾐ an emerging communication standard for building control components, driven by an ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) committee consisting of building facility operations personnel and building control industry supplier personnel. The intent is to create a communication standard that encompasses all facets of the ISO Reference Model plus an application layer that will enable multiple vendor products to intercommunicate and interoperate with one another. The final definition and availability of this standard has not yet been determined.
BAS (BUILDING AUTOMATION SYSTEM)
See BEMS
BASE BAND TRANSMISSION
Transmission of a digital or analog signal in its original form not changed by modulation.
BASIC
A high level programming language with a small number of statements and a simple syntax that is designated to be easily learned and used and that is widely used for interactive applications on computer or microcomputer.
In real-time systems the processing of related transactions that have been grouped together.
BCD (BINARY CODE DECIMAL)
A binary coded notation in which each of the decimal digit is represented by a binary numeral.
BEMS (BUILDING AND ENERGY MANAGEMENT SYSTEM)
A electronic control and monitoring system that has the ability to communicate data between control modes and operator terminal. The system can have attributes from all facets of building control and management functions such as HVAC, fire, security maintenance management and energy management.
For customary use only synonymous with BEMS.
BMS (BUILDING MANAGEMENT SYSTEM)
An operation which changes the operating temperature at a boiler usually according to the outside air temperature.
BROADCAST
A message transmission in which all attending stations receive the message. Messages are broadcast onto local area networks by the sending workstation, but only the addressee accepts and reads the message.
BAP (BUILDING AUTOMATION PROTOCOL)
A set of conventions used to govern the format and content of messages between devices and plant equipments.
BYTE
A string that consists of a number of bits, treated as a unit, and a group of 8 bit.
CAD (COMPUTER AIDED DESIGN)
the use of computer facilities as an aid in drafting and design.
CARRIER BAND TRANSMISSION
In data communication, a continuous frequency that can be modulated or impressed with an information carrying signal.
CENTRAL STATION
Primary “point” of access to a BEMS. The computer system from which all operations are conducted.
CENTRALIZED INTELLIGENCE
Description of a system where ALGORITHM processing is only possible at the CENTRAL STATION. The OUT STATIONS are dormant when not in contact with the CENTRAL STATION.
CENTRAL PROCESSING UNIT (CPU)
A processor that contains the sequencing and processing facilities for instruction execution, interruption action, timing functions, initial program loading, and other machine-related functions.
CHARACTER DISPLAY CRT
A display device used in computer equipment, can be mono-chrome or color, and only to character.
COAXIAL CABLE
A cable consisting of one conductor. Usually a small copper tube or wire, within and insulated from another conductor of large diameter. Usually copper tubing or copper braid.
CODING
Instructions written for a computer
CONSOLE
For customary use only. A part of computer used for communication between a human operator and the computer.
COOL DOWN PERIOD or PRECOOL PERIOD
The time taken for a measured temperature to reduce from some given higher value to a required SETPOINT.
DEAD BAND
A range of the controlled variable in which no corrective action is taken by the controlled system and no energy is used. See also “zero energy band”.
DEBUG
To defect, to locate, and to eliminate errors in computer programs
DEFAULT OPTION
See DEFAULT VALUE
DEFAULT VALUE
A reserved standard value or option to be used when no value or option is specified by the user or operator.
DESCENDER
In a font, the distance from the baseline to the bottom of the character box. This value may differ for different characters in given font.
DESIRED VALUE
See SETPOINT
DIGITAL
A representation of a value by means of discretely variable physical quantities.
DIGITAL SIGNAL INPUT/OUTPUT
Input for discrete electrical values, e.g., an impulse transducer for flow measurement totalization.
Output with discrete electrical values, e.g., a pump switching status (on/off)
DIRECT DIGITAL CONTROL
DDC. A controller technology that handles inputs and outputs electronically with software providing the logic.
DISC or DISK
A storage device consisting of a flat, circular plate coated on one or both sides with a magnetizable material.
DISK DRIVE
A physical unit that holds, spins, reads, and writes to magnetic DISKS
DOT MATRIX PRINTER
See MATRIX PRINTER
DRY CONTACTS
A relay contact which is pre-wired to a voltage or current source. (Open Contact)
DUAL SYSTEM
DUMP
To write all or part of the contents of a storage device to a PERIPHERAL for a specific purpose such as to allow other use of the storage space, or as a safeguard against faults or errors.
DUPLEX TRANSMISSION
Simultaneous independent transfer of DATA in two direction using software handshake mechanism. Synonymous with FULL DUPLEX.
DUTY CYCLING
A control method which alternates or cycles the sequence of plant use bringing standby plant regularly into use.
DYNAMIC GRAPHICS
Automatically updated readings of plant or space conditions superimposed on a plant layout diagram displayed on a VDU screen.
EMI
Electromagnetic interface
EMULATION
The imitation of all or part of a system by a computer system so that the imitating system accepts the same input, shows the same output and achieves the same results as the imitated computer system.
EMULATOR
An emulator is a computer system to which the BEMS have been installed, software emulates the building shell and plant controlled, sending sensor input signals to the BEMS and responding to output signals from the BEMS. The computer system is called an emulator rather than a simulator as the former runs in real-time whereas a simulation runs as far as the computer allow.
EMS (ENERGY MANAGEMENT SYSTEM)
Energy Management System. Synonymous with BEMS.
ENERGY REQUIREMENTS
The summation of the amounts of energy used in a building or process in a given period, usually one year.
ENERGY TARGET, ENERGY BUDGET
The desired total energy use in a building or process for a given period, usually one year.
ENVIRONMENTAL SERVICES, BUILDING SERVICES
All the plant and apparatus, including lighting, within a building intended to maintain the physical conditions of the internal environment.
ESTATE MANAGEMENT SYSTEM
A management system, usually computer based, designed for the administration of an estate of property. These systems are intended as a tool for carrying out such estate management functions as leasing, plant and building maintenance and optimizing use.
EVENT INITIATED PROGRAMS
COMPUTER PROGRAMS executed on the occurrence of an input/output operation or an ALARM.
EXPERT SYSTEM
A computer based facility for storing and interrogating an expert’s knowledge so that it can help in problem solving. See also ARTIFICIAL INTELLIGENCE.
FACILITY MANAGEMENT SYSTEM
A system which centralizes the monitoring, operations, and management of a building to achieve more efficient operations and utilities.
FEEDBACK CONTROL
Closed loop control where the control activating (error) signal is derived from the SETPOINT and a signal indicating the current value of the controlled medium.
FND (FIRMEN-NEUTRALS DATENUBERTRAGUNGSSYSTEM)
FND is a quasi standard promoted by AMEV in implement a manufactureﾕs independent communication system in buildings.
FIRMWARE
DATA and COMPUTER PROGRAMS stored in a NON-VOLATILE form such as hardwired or in a ROM/EPROM.
GRAPHIC DISPLAY
A display device that provides a representation of data in graphic form.
HANDSHAKE
A term used to describe how computers or PERIPHERALs can communicate without conflict. HANDSHAKE can be hardwired, where status is indicated by on/off electrical levels, or SOFTWARE based, where control characters are transmitted along with the information to be exchanged.
HARD COPY
DATA in a permanent and tangible form such as printed, punched or even handwritten.
HARD DISK (HD)
A rigid magnetic DISK. See DISK.
HARDWARE
All computer components that can be touched, such as the monitor, keyboard, central processing unit, etc.
HARDWIRED
Connected permanently by means of electrically conducting cables.
HEXADECIMAL (HEX)
A number system with a base of 16 using the digits 0 to 9 plus A, B, C, D, E, F to represent 10 to 15 respectively. Usually used for computer internal representation of DATA.
HIERARCHICAL CONFIGURATION
A system in which the processors and controllers are arranged in levels or tiers, with each tier having a definite rank or order in accessing and processing data. A typical arrangement includes, in descending order, management-level processors, operations-level processors, system-level controllers, and zone-level controllers.
HIGH LEVEL LANGUAGE
A computer programming vocabulary that can be used to create instructions to enable a CPU to manipulate DATA.
HUMIDISTAT
A device that responds to change in relative humidity and outputs a control signal. Usually mounted on a wall in the controlled space.
HVAC
HEATING VENTILATING & AIR CONDITIONING
HUNTING
A condition where a CONTROL FUNCTION is unable to achieve stability and is constantly adjusting itﾕs output. An undesirable condition.
ICON
A graphic symbol, displayed on an screen, that a user can point to with a device such as a mouse in order to select a particular function or software application.
INTELLIGENT OUTSTATION
See OUTSTATION
INTEGRAL CONTROL
A control regime where the correcting element is arranged to remain stationary when the controlled medium is at the desired value and to move in a corrective manner at an increasing speed proportional to the deviation of the controlled medium from the desired value.
INTERACTIVE
A mode of operation of a computer system in which a sequence of alternating entries and responses between a user and the system takes place in a manner similar to dialogue between two persons.
INTERLOCK
A term that describes the linking on one device to another in a control sequence.
KNOWLEDGE BASE
A storehouse of domain-specific knowledge in the form of empirical human knowledge, experimental data, and simulation results. This knowledge may be stored using the many representation structures: rules, frames, trees, or lists. The knowledge base of an expert system may actually contain several smaller knowledge bases appended with programs to pass information between them.
LED (Light Emitting Diode)
Light-emitting diode.
LIGHT PEN
A light-sensitive pick device that is used by pointing it at the display surface.
LOAD CYCLING
A control method where management of plant output is achieved by means of fixed on/off periods of operation. Used to prevent uncontrolled, fast switching operations.
LOCAL AREA NETWORK (LAN)
A cabling system with associated SOFTWARE that enables computer based systems to be physically linked so that they may communicate with each other without conflict.
LOCAL STATION
See OUTSTATION
LOG
A chronological record of a series of events. Each event is identified by time, day, value and physical reference.
LOGGING
The recording of data about specific events. Each event is identified by time, day, value and physical reference.
LOGICAL ADDRESS
An ADDRESS associated with the physical ADDRESS of each device by the appropriate device processor.
MACHINE CODE
The lowest level computer language where the program is written in the HEXADECIMAL or OCTAL equivalent of the CPU instruction code.
MASS STORAGE
Storage having a very large storage capacity.
MASTER STATION
A station that can select and transmit a message to a slave station.
MATRIX PRINTER
A printer in which each character is printed as a pattern of dots with needles.
MAXIMUM DEMAND CONTROL
See POWER DEMAND CONTROL.
MEMORY
Originally synonymous with RAM, where a CPU stores DATA for fast access. Now, with increasing use of “virtual” memory the distinction between memory and storage (DISCS) is less clear.