INFICON BCG450-SP ATM to Ultra-High Vacuum Triple Gauge (Profibus) - Manual (Page 43)

tira41e1 (2005-06) BCG450SPv1.cp
43
The following table explains terms used in connection with the Profibus.
Term Meaning
Alert Elements Alert Elements are used to communicate notification mes-
sages from slave to master when warnings, alarms or
events are detected.
Application A software functional unit consisting of an interconnected
aggregation of function blocks, events and objects, which
may be distributed and which may have interfaces with
other applications.
Characteristic An characteristic is a property or characteristic of an entity.
(Au) In block applications a block interface is defined by
input/output parameters. These parameters have charac-
teristics called parameter characteristics. Examples are
access rights and identification names.
(IT) The UML defines characteristics as a feature within a
classifier that describes a range of values that instances of
the classifier may hold. It is a property of a class instance
(object).
Block
(Block Instance) A logical processing unit of software comprising an individ-
ual, named copy of the block and associated parameters
specified by a block type, which persists from one invoca-
tion of the block to the next. Concept similar to the class/
object approach, but well suited to the automation require-
ments.
Class (IT) A class represents a template for several objects and
describes how these objects are structured internally. Ob-
jects of the same class have the same definition both for
their operations and for their information structures.
Configuration (of a
system/device) A step in system design: selecting functional units, assign-
ing their locations and identifiers and defining their inter-
connections.
Data Structure An aggregate whose elements need not be of the same
data type, and each of them is uniquely referenced by an
offset identifier.
Data Type A data item with certain characteristics and permissible
operations on that data, e.g. INT8.
Device A physical entity capable of performing one or more speci-
fied functions in a particular context and delimited by its
interfaces.
Direction of Data Input data are transmitted from the device to the bus. Out-
put data are transmitted from the bus to the device.
Direction of Flow A positive set point causes a flow from P to A.
Entity A particular thing, such as a person, place, process, object,
concept, association or event.
Function (1) A specific purpose of an entity.
(2) One of a group of actions performed by an entity.
Function Block A named block consisting of one or more input, output and
contained parameters. Function blocks represent the basic
automation functions performed by an application which is
as independent as possible from the specifics of I/O devices
and the network. Each function block processes input
parameters according to a specified algorithm and an inter-
nal set of contained parameters. They produce output pa-
rameters that are available for use within the same function
block application or by other function block applications.
Excerpts from:
"PROFIBUS Profile for SEMI"
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→ 4)