16
Rockwell Automation Publication 1756-RM093J-EN-P - April 2018
Chapter 1
Safety Integrity Level (SIL) Concept
Expansion slots of a SIL 3 system bus that are not used by the 1768 SIL 3 system
may be populated with other CompactLogix™ (1768) modules that are certified
to the Low Voltage and EMC Directives. To find the certificates for the
‘Programmable Control – CompactLogix Product Family’, refer to
http://www.rockwellautomation.com/products/certification/ce/
GuardLogix Certifications
The ControlLogix Controllers Technical Data, publication
lists
the product specifications and the agency certifications for which the products
are approved. If a product has achieved agency certification, it is marked as such
on the product labeling. See the Product Certification link at
www.rockwellautomation.com/products/certification/
for Declarations of
Conformity, Certificates, and other certification details.
GuardLogix PFD and PFH
Specifications
Safety-related systems can be classified as operating in either a Low Demand
mode, or in a High Demand/Continuous mode. IEC 61508 quantifies this
classification by stating that the frequency of demands for operation of the safety
system is no greater than once per year in the Low Demand mode, or greater than
once per year in High Demand/Continuous mode.
The Safety Integrity Level (SIL) value for a Low Demand safety-related system is
directly related to order-of-magnitude ranges of its average probability of failure
to satisfactorily perform its safety function on demand or, simply, probability of
failure on demand (PFD). The SIL value for a High Demand/Continuous mode
safety-related system is directly related to the probability of a dangerous failure
occurring per hour (PFH).
Table 4 - Components Suitable for Use With 1768 Compact GuardLogix Controller Safety Systems
Device Type
Cat. No.
Description
Related Documentation
(2)
Series
(1)
Revision
(1)
Installation
Instructions
User Manual
Power supply
1768-PA3
Power supply, AC
N/A
N/A
N/A
1768-PB3
Power supply, DC
N/A
N/A
Communication
modules
1768-ENBT
EtherNet/IP bridge module
A
3.1.1
1734-AENT
POINT I/O
™
Ethernet Adapter
A
3.001
1734-AENTR
POINT I/O Ethernet Adapter
A
3.001
N/A
1768-CNB
ControlNet bridge module
A
2.1.1
Programming
software
9324-
xxxx
RSLogix 5000 software
N/A
18
N/A
Consult online help.
Memory Cards
1784-CF128
128 MB CompactFlash Card
N/A
N/A
N/A
N/A
(1) This revision or version or later.
(2) These publications are available from Rockwell Automation by visiting
