Reference Manual Owner's manual

12 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 —