© 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
Machine Code
A representation of instructions and data that is directly executable by a computer (machine language)
MCC
Motor Control Centre
Manufacturing Execution System
Methods
A method is an organised collection of notations, techniques and formal or semi-formal procedures for carrying out one or more of the major life cycle activities. It will identify the deliverables and prescribe the form of the notation in which they are to be produced.
MHCS
Materials Handling Control System.
Milestone
A milestone is a major point in a project life cycle where a particular stage is completed and stock taken of performance, progress and quality. It is the documentation and reviews which provide tangible and objective milestones throughout the system development life cycle.
In theory, no life cycle stage shall be considered complete unless all necessary documentation has been completed to specified standards, nor shall the subsequent stage be started unless these requirements have been met. In practice project plans must reflect particular project needs for prototype development and occasional parallel activity, but such plans must call for the production of deliverables which can be assessed and be related to parallel activities where relevant.
MIS
Management Information System
MMI
MMI - an abbreviation for Man Machine Interface.
Model
A representation of logical construct. A model is usually presented as a collection of diagrams and a data dictionary.
Modem
Name derived from modulator/demodulator equipment used to translate digital information into analogue signals for transmission and receipt over voice telephone lines.
Modularity
The extent to which software is composed of discrete components such that a change to one component has minimal impact on other components.
MRP II
MRP II - Manufacturing Resource Planning
MRP
Materials Requirements Planning
MTBF
MTBF - Mean Time Between Failures. The expectation of the time between failures [BS 4778 Part 3]
MTTR
MTTR - Mean Time to Repair.
Multiplexer _ MUX
Equipment used to reduce information from many inputs to a single signal capable of being transmitted over a single communication channel in order to reduce field cabling costs. At the receiver end a demultiplexer is required to reconstitute the individual signals unless the MUX transmits directly as serial communications to the process control system.
Network
An interconnected or interrelated group of nodes.
Network Layer
One of the protocol layers in the OSI seven layer model. This layer is concerned with controlling the operation of the subnet. A key design issue is determining how packets are routed from source to destination.
Notation
A notation (formal or otherwise) is a means of recording information about a system; it is more restrictive and therefore more structured than ordinary English and may be diagrammatic.
NUI
Network Update Interval
Object
The word "object" is frequently used to describe a piece of software.
OIT
Abbreviation for Operator Interface Terminal
Operating System
The set of proprietary software programs running on a computer that function as the interface between the hardware and the application software packages.
OQ
Operational Qualification
OSI Reference Model
The OSI reference model was developed to define open systems communications. It comprised seven layers derived from applying the following principles:
A layer should be created where a different level of abstraction is needed.
Each layer should perform a well defined function.
The function of each layer should be chosen with an eye toward defining internationally standardised protocols.
The layer boundaries should be chosen to minimise the information fowl across the interfaces.
The number of layers should be large enough that distinct functions need not be thrown together in the same layer out of necessity, and small enough that the architecture does not become unwieldy.
