© Tony Simmons 2008
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
Acceptance criteria
The criteria a software product must meet to successfully complete a test phase or to achieve delivery requirements.
ADSL
Asymmetric Digital Subscriber Line. The technology allows an existing phone line to be used for data communications and multimedia applications in parallel with the regular telephone service. The modems at either end of the link, between the exchange and customer, operate in such a way as to achieve data rates much higher than is possible with normal analogue voice-band modems. The asymmetric results from the fact that the downstream rate towards the customer (~MBit./s) is higher than the upstream (10s or 100s kbit/s).
Alarm
A visual and audible indication of a problem such as the excursion of a process variable from predefined boundary values or the triggering of a trip or interlock.
ALARP
ALARP - As Low As Reasonable Practical. A term applied to the reduction of risk by taking measures to reduce risk to persons (between intolerable and negligible levels) until the cost of further measures is grossly disproportionate to the benefits they would deliver.
Application layer
One of the protocol layers in the OSI seven layer model. The application layer contains a variety of protocols that are commonly needed. Such functions include file transfer protocols (FTP), virtual terminal protocols, and so on.
Application software
Software written specifically for the users project application. Such software is generally written using a control systems proprietary system software package.
A program adapted or tailored to the specific user requirements for the purpose of data collection, data manipulation, data archiving, or process control. [GAMP]
ASI
AS-Interface (AS-i) is a simple networking solution for actuators and sensors in manufacturing systems. It uses a distinct flat yellow cable and is an 'open' technology supported by over 100 vendors worldwide.
An AS-Interface network offers a cost-efficient alternative to conventional cabling at the lowest level of the automation hierarchy where it can operate stand-alone or with a controller. A network can also link into a higher level fieldbus for low-cost remote I/O.
Audit
An activity to determine through investigation the adequacy of, and adherence to, established procedures, instructions, specifications, codes, and standards or other applicable contractual and licensing requirements, and the effectiveness of implementation. [GAMP]
Automated system
Term applied to a broad range of systems, including automated manufacturing equipment, control systems, automated laboratory systems, manufacturing execution systems, and computers running laboratory or manufacturing database systems. The automated system consists of the hardware, software and network components, together with the controlled functions and associated documentation. [GAMP]
Availability
The ability of an item (under the combined aspects of its reliability, maintainability and maintenance support) to perform its required function at a stated instant of time over a stated period of time. [BS 5760 Part 0]
