Rockwell Automation 1756-L7x GuardLogix 5570 Controllers - Manual (Page 14)

14 Rockwell Automation Publication 1756-UM022A-EN-P - November 2012
Chapter 1 System Overview
Selecting System Hardware The GuardLogix system supports SIL 3 and PLe safety applications. The
GuardLogix controller is made up of a primary controller and a safety partner
that function together in a 1oo2 architecture.
Table 4 lists catalog numbers for
primary controllers and safety partners.
The safety partner must be installed in the slot immediately to the right of the
primary controller. The firmware major and minor revisions of the primary
controller and safety partner must match exactly to establish the control
partnership required for safety applications.
Primary Controller
The primary controller is the processor that performs standard and safety
functions and communicates with the safety partner for safety-related functions
in the GuardLogix control system. Standard functions include the following:
• I/O control
• Logic
• Timing
• Counting
• Report generation
• Communication
• Arithmetic computations
• Data file manipulation
The primary controller consists of a central processor, I/O interface, and
memory.
A three-position keyswitch on the front of the primary controller governs the
controller operational modes. The following modes are available:
• RUN
• PROGram
• REMote - this software-enabled mode can be Program, Run, or Test
Table 4 - Primary Controller and Corresponding Safety Partner Catalog Numbers
Primary Controller Safety Partner
1756-L71S, 1756-L72S, 1756-L73S 1756-L7SP
1756-L73SXT 1756-L7SPXT
Table 5 - Memory Capacity
Cat. No.
User Memory (RAM capacity)
Standard Tasks and Components Safety Task and Components
1756-L71S 2MB 1 MB
1756-L72S 4 MB 2 MB
1756-L73S,1756-L73SXT 8 MB 4 MB