Terms And Definitions - ABB SpiritIT Flow-X Instruction Manual

S P I R I T

Terms and definitions

Throughout this manual the following additional terms and definitions are used:
Asynchronous A type of message passing where the sending task does not wait for a reply before continuing processing. If the receiving task cannot
take the message immediately, the message often waits on a queue until it can be received.
Client/server A network architecture in which each computer or process on the network is either a client or a server. Clients rely on servers for
resources, such as files, devices, and even processing power.
Another type of network architecture is known as a peer-to-peer architecture. Both client/server and peer-to-peer architectures are widely
used, and each has unique advantages and disadvantages. Client/server architectures are sometimes called two-tier architectures
Device driver A program that sends and receives data to and from the outside world. Typically a device driver will communicate with a hardware
interface card that receives field device messages and maps their content into a region of memory on the card. The device driver then
reads this memory and delivers the contents to the spreadsheet.
Engineering units Engineering units as used throughout this manual refers in general to the units of a tag, for example 'bar', or 'ºC', and not to a type of unit,
as with 'metric' units, or 'imperial' units.
Ethernet A LAN protocol developed by Xerox in cooperation with DEC and Intel in 1976. Standard Ethernet supports data transfer rates of 10 Mbps.
The Ethernet specification served as the basis for the IEEE 802.3 standard, which specifies physical and lower software layers. A newer
version, called 100-Base-T or Fast Ethernet supports data transfer rates of 100 Mbps, while the newest version, Gigabit Ethernet supports
rates of 1 gigabit (1000 megabits) per second.
Event Anything that happens that is significant to a program, such as a mouse click, a change in a data point value, or a command from a user.
Exception Any condition, such as a hardware interrupt or software error-handler, that changes a program's flow of control.
Fieldbus A set of communication protocols that various hardware manufacturers use to make their field devices talk to other field devices. Fieldbus
protocols are often supported by manufacturers of sensor hardware. There are debates as to which of the different fieldbus protocols is
the best. Popular types of fieldbus protocol include Modbus, Hart, Profibus, Devicenet, InterBus, and CANopen.
Kernel The core of Spirit
Peer-to-peer A type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures,
in which some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler, but they usually do not offer
the same performance under heavy loads. Peer-to-peer is sometimes shortened to the term P2P.
Polling A method of updating data in a system, where one task sends a message to a second task on a regular basis, to check if a data point has
changed. If so, the change in data is sent to the first task. This method is most effective when there are few data points in the system.
Otherwise, exception handling is generally faster.
Process visualization A system for monitoring and controlling for production processes, and managing related data. Typically such a system is connected to
software external devices, which are in turn connected to sensors and production machinery.
The term 'process visualization software' in this document is generally used for software with which SCADA software, HMI software, or
supervisory computer software applications can be built. In this document, although strictly not correct, the terms 'SCADA, 'HMI,
'supervisory', and 'process visualization' are alternately used, and refer to the computer software applications that can be realized with
IT
Spirit eXLerate, a PC-based supervisory software.
Protocol An agreed-up format for transmitting data between two devices. In this context, a protocol mostly references to the Data Link Layer in the
OSI 7-Layer Communication Model.
Query In SCADA/HMI terms a message from a computer to a client in a master/client configuration utilizing the message protocol with the
purpose to request for information. Usually, more than 1 data-point is transmitted in a single query.
Real-time The characteristic of determinism applied to computer hardware and/or software. A real-time process must perform a task in a
determined length of time.
The phrase "real-time" does not directly relate to how fast the program responds, even though many people believe that real-time means
real-fast.
Resource Any component of a computing machine that can be utilized by software. Examples include: RAM, disk space, CPU time, real-world time,
serial devices, network devices, and other hardware, as well as O/S objects such as semaphores, timers, file descriptors, files, etc.
Synchronous A type of message passing where the sending task waits for a reply before continuing processing.
Tag A 'tag' as used within this document refers to a data point existing in the tag database, with a number of properties, such as its assigned
I/O address, current value, engineering units, description, alias name, and many others.
Web Server A computer that has server software installed on it and is used to deliver web pages to an intranet/Internet.
I T F L O W - X I N S T R U C T I O N M A N U A L | I M / F L O W X - E N
IT
Flow-X that handles basic functions, such as hardware and/or software interfaces, or resource allocation.
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