Terminology – Rockwell Automation 21G PowerFlex 750-Series AC Drives Reference Manual User Manual

Page 12

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Rockwell Automation Publication 750-RM001F-EN-P - February 2012

Preface

Terminology

This table defines abbreviations used in this manual.

Abbreviation

Full Term

Definition

1oo2

One out of Two

Refers to the behavioral design of a dual-channel safety system.

CAT

Category

CL

Capability Level

DC

Door Control

DM

Door Monitoring

EN

European Norm

The official European Standard.

ESD

Emergency Shutdown Systems

ESM

Enabling Switch Monitoring

ESPE

Electro-sensitive Protective Equipment

An assembly of devices and/or components working together for protective tripping or presence-
sensing purposes and comprising as a minimum:
a sensing device.
controlling/monitoring devices.
output signal-switching devices (OSSD).

FMEA

Failure Mode and Effects Analysis

FV

Flux Vector

HFT

Hardware Fault Tolerance

The HFT equals n, where n+1 faults could cause the loss of the safety function. An HFT of 1 means that
2 faults are required before safety is lost.

HIM

Human Interface Module

A module used to configure a device.

IEC

International Electrotechnical Commission

IGBT

Insulated Gate Bi-polar Transistors

Typical power switch used to control main current.

ISO

International Organization for Standardization

LM

Lock Monitoring

MP

Motion Power

NC

Normally Closed

A set of contacts on a relay or switch that are closed when the relay is de-energized or the switch is de-
activated.

NO

Normally Open

A set of contacts on a relay or switch that are open when the relay is de-energized or the switch is de-
activated.

OSSD

Output Signal Switching Device

The component of the electro-sensitive protective equipment (ESPE) connected to the control system
of a machine, which, when the sensing device is actuated during normal operation, responds by going
to the OFF-state.

PC

Personal Computer

Computer used to interface with and program your safety system.

PELV

Protective Extra Low Voltage

An electrical system in which the voltage cannot exceed ELV under normal conditions, and under
single-fault conditions, except earth faults in other circuits.

PFD

Probability of Failure on Demand

The average probability of a system to fail to perform its design function on demand.

PFH

Probability of Failure per Hour

The probability of a system to have a dangerous failure occur per hour.

PL

Performance Level

ISO 13849-1 safety rating

PM

Permanent Magnet

PTI

Proof Test Interval

SDM

Safe Direction Monitoring

SELV

Safety Extra Low Voltage Circuit

A secondary circuit which is so designed and protected that, under normal and single fault conditions,
its voltages do not exceed a safe value.

SFF

Safe Failure Fraction

The sum of safe failures plus the sum of dangerous detected failures divided by the sum of all failures.

SIL

Safety Integrity Level

A measure of a products ability to lower the risk that a dangerous failure could occur.

SLS

Safe Limited Speed

SMA

Safe Maximum Acceleration

SMS

Safe Maximum Speed

SS

Safe Stop

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