© Tony Simmons 2010
Select the first letter of the word from the list above to jump to appropriate section of the glossary. If the term you are looking for starts with a digit or symbol, choose the '#' link.
Glossary of Automation & Control Engineering Terms
F&G
F&G - Fire and Gas
Fail Safe
A design property of an item which prevents its failures from resulting in critical faults. [BS 4778 Part 3]
Failure
The termination of the ability of a system hardware element to perform a required function. (Note: hardware can fail but software can only have faults.)
Fault
A "fault" in software is a discrepancy between its intended or specified operation and what it actually does. During testing, apparent discrepancies can arise; this can be where the software is correct but one of the test specifications is flawed.
Fault is one of the three possible categories given to an observation raised by a Comment Sheet (see Comment Sheet). Once the fault has been rectified the area and supporting documentation is cross referred to the originating Comment Sheet when the Comment Sheet is signed off as being complete.
Fault Tree
A logic diagram showing which fault modes of sub-items or external events, or combinations thereof, result in a given fault mode of the item. [BS 4778 Part 3]
FBD
Function Block Diagram.
FDL
PROFIBUS layer 2 component called Fieldbus Data Link (FDL
FDT
Field Device Tools is a software kernel that can operate on any platform to support the use of remote device parameter interrogation by a remote software package.
FDT enables the integration of devices from different makers regardless of which fieldbus protocol is used.
FEHM
FEHM - Fire and Explosion Hazard Management.
Field
The term field is used to describe the area of plant where processing or manufacturing takes place, as in 'field equipment' or 'field mounted'.
Field Bus
Fieldbus is a generic name given to fully-digital communication protocols for industrial measurement and control applications.
Housing for the terminals where multi-core cables carrying signals from the field are cross-connected to signal cables going to the computer input/output cards. Usually two sets of terminals are used with short wires between doing the cross connection. See also marshalling rack.
Fire wall
Hardware/software barrier between the Internet and an internal network, attempting to prevent the passage of 'dangerous' code and unauthorised access.
System software which is embedded in unalterable hardware memory and inaccessible to the programmer.
FMEA
FMEA - Failure Modes and Effects Analysis. A qualitative method of reliability analysis which involves the study of the fault modes which can exist in every sub-item of the item and the determination of the effects of each fault mode on the other sub-items of the item and on the required functions of the item. [BS 4778 Part 3]
Formal Methods
Mathematically based techniques whose rigorous application enables the correctness of software to be verified again the specification of that software. For this process to take place there must also be a formal specification. The creation of this specification is itself part of formal methods. [IEE/BCS report]
Frozen Software
Software which is under configuration control and may not be altered without change control. [GAMP]
Functional Block
A Function Block is part of a control program that is packaged so that it can be re-used. See IEC61131-3
Function Block Diagram
A graphical language for depicting signal and data flows through function blocks. See IEC61131-3
Functional Requirements
Unlike User requirements, which may be general and concentrated on the users perspective, functional requirements define completely the logical, sequential and continuous control, data handling etc. in all the detail required to implement the system. The Functional Requirement is a deliverable from the Requirements Analysis activity and it may be expressed in the form of a model. (Usually issued as the Functional Specification)
Functional Safety
The ability of a safety related system to carry out the actions necessary to bring the plant to a safe state. [IEC 61508]
Functional Specification
A functional specification (or Functional Design Specification - FDS) is the specification that describes 'how' the control system functionality will be achieved. See Requirements Specification
Functional Testing
Also known as "black box testing" since source code is not needed. Involves inputting normal and abnormal test cases; then, evaluating outputs against those expected.
