Rockwell Automation AADvance Controller System Build User Manual

Page 125

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Document: 553632
(ICSTT-RM448_EN_P) Issue: 08:

8-7

Chapter 7

Glossary of Terms

processor module

processor module

processor module

processor module

The application execution engine of the
AADvance controller, housed in a self-
contained and standardized physical form
factor.

producer

producer

producer

producer

A controller producing a tag to one or more
consumers, at the request of the consumers.

program enable key

program enable key

program enable key

program enable key

A security device that protects the
application from unauthorized access and
change, in the form factor of a 9-way 'D'
type plug. Part number 9906. Supplied with
the processor base unit. See also 'key
connector'.

project

project

project

project

A collection of configurations and the
definition of the linking between them. See
'configuration'.

protocol

protocol

protocol

protocol

A set of rules that is used by devices (such
as AADvance controllers, serial devices and
engineering workstations) to communicate
with each other. The rules encompass
electrical parameters, data representation,
signalling, authentication, and error
detection. Examples include Modbus, TCP
and IP.

PST

PST

PST

PST

Process Safety Time

R

R

R

R

real

real

real

real

A class of analogue variable stored in a
floating, single-precision 32-bit format.

redundancy

redundancy

redundancy

redundancy

The use of two or more devices, each
carrying out the same function, to improve
reliability or availability.

resolution

resolution

resolution

resolution

The smallest interval measurable by an
instrument; the level of detail which may be
represented. For example, 12 bits can
distinguish between 4096 values.

RS

RS

RS

RS----232

232

232

232----C, RS

C, RS

C, RS

C, RS----422, RS

422, RS

422, RS

422, RS----485

485

485

485

Standard interfaces introduced by the
Electronic Industries Alliance covering the
electrical connection between data
communication equipment. RS-232-C is the
most commonly used interface; RS-422 and
RS-485 allow for higher transmission rates
over increased distances.

RTC

RTC

RTC

RTC

Real-time clock.

RTU

RTU

RTU

RTU

Remote terminal unit. The Modbus protocol
supported by the AADvance controller for
Modbus communications over serial links,
with the ability to multi-drop to multiple
slave devices.

S

S

S

S

safe state

safe state

safe state

safe state

A state which enables the execution of a
process demand. Usually entered after the
detection of a fault condition; it makes sure
the effect of the fault is to enable rather
than disable a process demand.

safety accuracy

safety accuracy

safety accuracy

safety accuracy

The accuracy of an analogue signal within
which the signal is guaranteed to be free of
dangerous faults. If the signal drifts outside
of this range, it is declared faulty.

safety

safety

safety

safety----critical state

critical state

critical state

critical state

A faulted state which prevents the
execution of a process demand.

sensor

sensor

sensor

sensor

A device or combination of devices that
measure a process condition. Examples are
transmitters, transducers, process switches
and position switches.

sequential function chart

sequential function chart

sequential function chart

sequential function chart

An IEC 61131 language that divides the
process cycle into a number of well-defined
steps separated by transitions. See 'limited
variability language'.

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