Glossary List_1

Term	Definition
Acyclic Period	The Acyclic Period is that portion of the communication cycle time, during which information other than Publish/Subscribe data is transmitted. Typical information transmitted during this time includes Alarms/Events, Maintenance/Diagnostic Information, Program Invocations, Permissives/Interlocks, Display information, Trend Information and Configuration.
Application Layer	The Application Layer is a layer in the communication stack containing the object dictionary.
Auto Sense	Auto Sense is the capability of the system to automatically detect and recognize any hardware upon addition to, or removal from, the system without any user intervention.
Automation System	A process automation, control, and diagnostic system that is composed of distinct modules. These modules may be physically and functionally distributed over the plant area. The automation system contains all the modules and associated software required to accomplish the regulatory control and monitoring of a process plant. This definition of automation system excludes field instruments, remote terminal units, auxiliary systems and management information systems.
Auxiliary System	An Auxiliary System is a control and/or monitoring system that is stand-alone, performs a specialized task, and communicates with the automation system.
Basic Device	A Basic Device is any device not having the capability to control communications on an H1 fieldbus segment.
Brick	A Brick is a fully connectorized passive junction located on the bus.
Bus	A Bus is an H1 fieldbus cable between a host and field devices connected to multiple segments, sometimes through the use of repeaters.
Capabilities File	A Capabilities File describes the communication objects in a fieldbus device. A configuration device can use Device Description (DD) Files and Capabilities Files to configure a fieldbus system without having the fieldbus devices online.
Common File Format File (CFF)	A Common File Format File is a software file used by the host to know the device detailed FF capabilities without requiring the actual device. This file format is used for Capabilities and Value files.
Communications Stack	A Communications Stack is a layered software supporting communication between devices. It is the device communications software which provides encoding and decoding of User Layer messages, deterministic control of message transmission, and message transfer.
Configurable	The capability to select and connect standard hardware modules to create a system; or the capability to change functionality or sizing of software functions by changing parameters without having to modify or regenerate software.
Configuration	The physical installation of hardware modules to satisfy system requirements; or the selection of software options to satisfy system requirements.
Connector	A Connector is a coupling device used to connect the wire medium to a fieldbus device or to another segment of wire.
Console	A Console is a collection of one or more workstations and associated equipment such as printers and communications devices used by an individual to interact with the automation system and perform other functions.
Control Loop	A Control Loop is a group of Function Blocks (FBs) that execute at a specified rate within a fieldbus device or distributed across the fieldbus network.
Coupler	A Coupler is a physical interface between a trunk and spur, or a trunk and a device.
Cycle	The scanning of inputs, execution of algorithms and transmission of output values to devices.
Data Link Layer (DLL)	The Data Link Layer (DLL) controls transmission of messages onto the fieldbus, and manages access to the fieldbus through the Link Active Scheduler (LAS). The DLL used by Foundationfieldbus is defined in IEC 61158 and ISA S50. It includes Publisher/Subscriber, Client/Server and Source/Sink services.
Deterministic	The ability to measure the maximum worst-case delay in delivery of a message between any two nodes in a network. Any network protocol that depends on random delays to resolve mastership is nondeterministic.
Device Description (DD)	A Device Description (DD) provides an extended description of each object in the Virtual Field Device (VFD), and includes information needed for a control system or host to understand the meaning of data in the VFD.
DI	Discrete Input – the signal is from the field device to the host system.
Discrete Control	Control where inputs, algorithms and outputs are based on logical (yes or no) values. In the case of Foundation fieldbus, discrete includes any integer operation between 0-255.
DO	Discrete Output – the signal is generated by the host system and transmitted to a field device.
EDDL	Enhanced Device Description Language
Ethernet	Physical and data link layer used by HSE fieldbus
Factory Acceptance Test (FAT)	The Factory Acceptance Test (FAT) is the final test at the vendor's facility of the integrated system being purchased.
FF	Foundation fieldbus
Fieldbus	A Fieldbus is a digital, two-way, multi-drop communication link among intelligent measurement and control devices. It serves as a Local Area Network (LAN) for advanced process control, remote input/output and high speed factory automation applications.
Fieldbus Access Sublayer (FAS)	The Fieldbus Access Sublayer (FAS) maps the Fieldbus Message Specification (FMS) onto the Data Link Layer (DLL).
Fieldbus Messaging Specification (FMS)	The Fieldbus Messaging Specification (FMS) contains definitions of Application Layer services in Foundation fieldbus. The FMS specifies services and message formats for accessing Function Block (FB) parameters, as well as Object Dictionary (OD) descriptions for those parameters defined in the Virtual Field Device (VFD). Comments: Network Management (NM) permits FOUNDATION Network Manager (NMgr) entities to conduct management operations over the network using Network Management Agents (NMAs). Each NMA is responsible for managing the communications within a device. The NMgr and NMA communicate through use of the FMS and Virtual Communications Relationship (VCR).
FISCO	Fieldbus Intrinsic Safe COncept. Allows more power to an IS segment for approved FISCO devices, allowing for more devices per IS segment. Comments: FISCO eliminates the requirement of calculating entity parameters of capacitance and inductance when designing networks.
Flexible Function Block (FFB)	A Flexible Function Block (FFB) is similar to a Standard FB, except that an application specific algorithm created by a programming tool determines the function of the block, the order and definition of the block parameters, and the time required to execute the block. Flexible Function Blocks (FFBs) are typically used for control of discrete processes and for hybrid (batch) processes. A Programmable Logic Controller (PLC) can be modeled as a Flexible Function Block device.
FNICO	Fieldbus Non-Incendive COncept. Allows more power to a fieldbus segment in a Zone 2 Area, thus allowing for more devices per segment.
Gateway	A Gateway translates another protocol to fieldbus, for example HART to fieldbus or Modbus to fieldbus.
H1	H1 is a term used to describe a fieldbus network operating at 31.25 kbit/second.
H1 Field Device	An H1 Field Device is a fieldbus device connected directly to an H1 fieldbus. Typical H1 Field Devices are valves and transmitters.
H1 Repeater	An H1 Repeater is an active, bus-powered or non-bus-powered device used to extend the range over which signals can be correctly transmitted and received for a given medium. A maximum of four Repeaters and/or active Couplers can be used between any two devices on an H1 fieldbus network. Repeaters connect segments together to form larger networks.
High Speed Ethernet (HSE)	High Speed Ethernet (HSE) is the Fieldbus Foundation's backbone network running Ethernet and IP.
HIST	Host Interoperability Support Test performed by the foundation to test host conformance to the Foundation specifications.
HSE Field Device	An HSE Field Device is a fieldbus device connected directly to a High Speed Ethernet (HSE) fieldbus. Typical HSE Field Devices are HSE Linking Devices, HSE Field Devices running Function Blocks (FBs), and Host Computers.
HSE Linking Device	An HSE Linking Device is a device used to interconnect H1 fieldbus networks/segments to High Speed Ethernet (HSE) to create a larger system.
HSE Switch	An HSE Switch is standard Ethernet equipment used to interconnect multiple High Speed Ethernet (HSE) devices such as HSE Linking Devices and HSE Field Devices to form a larger HSE network.
Input/Output (I/O) Subsystem Interface	An Input/Output (I/O) Subsystem Interface is a device used to connect other types of communications protocols to a fieldbus Segment or Segments.
Instantiable	The ability, for function block, to create multiple tagged function blocks of different types from a library as required by the application. Quantity per device restricted by device memory and other resources.
Interchangeability	Interchangeability is the capability to substitute a device from one manufacturer with that of another manufacturer on a fieldbus network without loss of functionality or degree of integration.
Interoperability	Interoperability is the capability for a device from one manufacturer to interact with that of another manufacturer on a fieldbus network without loss of functionality.
IS	Intrinsic Safety
ITK	Interoperability Test Kit used by the foundation to register devices and confirm compliance with the relevant Foundationstandards. This is a pass/fail test. Only devices passing the full suite of tests receive the foundation's official registration mark.
Junction Box / Quick Connection Station	A Junction Box/Quick Connection Station allows for quick installation of four to eight field instruments via terminal connectors.