Rockwell Automation T8094 8000 Series TMR System Safety Manual - Manual (Page 13)

SAFETY MANUAL
D oc N umber T8094
I ssue 27 – June 2013
Page xi ii
MORSE Method for Object Reuse in Safety-critical
Environments.
Programming and
configuration software tool for the Fastflex
range of Remote I/O.
Output Module Interface that converts output signals from the
control system into signals that can actuate
external devices.
Peer-to-Peer
Communications
Allows two or more TMR Controllers to
communicate with each other.
PCM PCI Mezzanine Card
Protocol A set of rules governing data flow in a
communication system. The protocol governs
such matters as the way a message is
addressed and routed, how often it is sent,
how to recover from transmission errors and
how much information is to be sent.
PSU Power Supply Unit.
RAM Random Access Memory. A volatile (unless
battery backed) form of read/write memory.
The time to access different locations is the
same. It may be static (SRAM - data held in a
flip- flop) or dynamic (DRAM – data held as a
capacitive charge).
Real Time A method of data processing in which the data
is acted upon immediately instead of being
accumulated and processed in batches.
Redundancy The employment of two or more devices, each
performing the same function, in order to
improve reliability.
RISC Reduced Instruction Set Computer
RS-232C,
RS-422,
RS-485
Standard interfaces introduced by the Energy
Industries Association covering the electrical
connection between data communication
equipment. RS-232C is the most commonly
used interface,. However, RS-422 allows for
high transmission rates over greatly increased
distances.
RTU Remote Telemetry Unit
Safety Where TÜV certification is a requirement, the
Safety Chapter prescribes how to use the TMR
system in a safety-related application.
SFC Sequential Function Chart. A IEC1131
language that divides the process cycle into a
number of well-defined steps separated by
transitions.