Rockwell Automation 1756-SPESMNRMXT GuardLogix Controllers User Manual - Manuel (Page 12)

12 Rockwell Automation Publication 1756-UM020I-EN-P - August 2012
Preface
The extreme environment GuardLogix controller, catalog numbers
1756-L73SXT and 1756-L7SPXT, provides the same functionality as the
1756-L73S controller, but is designed to withstand temperatures of
-25...70 °C (-13...158 °F).
Understanding Terminology This table defines terms used in this manual.
IMPORTANT Logix-XT system components are rated for extreme environmental conditions
only when used properly with other Logix-XT system components. The use of
Logix-XT components with traditional Logix system components nullifies
extreme-environment ratings.
Table 2 - Terms and Definitions
Abbreviation Full Term Definition
1oo2 One Out of Two Refers to the behavioral design of a multi-processor safety system.
CIP Common Industrial Protocol A communication protocol designed for industrial automation applications.
CIP Safety Common Industrial Protocol – Safety Certified SIL 3/PLe rated version of CIP.
DC Diagnostic Coverage The ratio of the detected failure rate to the total failure rate.
EN European Norm. The official European standard.
ESM Energy Storage Module Used for clock support and backup for memory retention at powerdown on 1756-L7xS and 1756-L73SXT
controllers.
GSV Get System Value An instruction that retrieves specified controller-status information and places it in a destination tag.
— Multicast The transmission of information from one sender to multiple receivers.
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.
RPI Requested Packet Interval The expected rate in time for production of data when communicating over a network.
SNN Safety Network Number A unique number that identifies a section of a safety network.
SSV Set System Value An instruction that sets controller system data.
— Standard An object, task, tag, program, or component in your project that is not a safety-related item.
— Unicast The transmission of information from one sender to one receiver.