Rockwell Automation 1768-L45S Compact GuardLogix Controllers - Manual (Page 109)

Rockwell Automation Publication 1768-UM002C-EN-P - April 2012 109
Monitor Status and Handle Faults Chapter 8
Controller Fault Handler
The controller fault handler is an optional component that executes when the
program fault routine could not clear the fault or does not exist.
You can create only one program for the controller fault handler. After you create
that program, you must configure a routine as the main routine.
The Logix5000 Controllers Major and Minor Faults Programming Manual,
publication
1756-PM014 , provides details on creating and testing a fault routine.
Use GSV/SSV Instructions
Logix controllers store system data in objects rather than in status files. You can
use the Get System Value (GSV) and Set System Value (SSV) instructions to
retrieve and set controller data.
The GSV instruction retrieves the specified information and places it in the
specified destination. The SSV instruction changes the specified attribute with
data from the source of the instruction. When you enter a GSV or SSV
instruction, the programming software displays the object classes, object names,
and attribute names for each instruction.
For standard tasks, you can use the GSV instruction to get values for the available
attributes. When using the SSV instruction, the software displays only those
attributes you are allowed to set.
For the safety task, the GSV and SSV instructions are more restricted. Note that
SSV instructions in safety and standard tasks cannot set bit 0 (major fault on
error) in the mode attribute of a Safety I/O module.
For safety objects, the Table 32 shows which attributes you can get values for by
using the GSV instruction, and which attributes you are allowed to set by using
the SSV instruction, in the safety and standard tasks.
ATTENTION: Use the GSV/SSV instructions carefully. Making changes to
objects can cause unexpected controller operation or injury to personnel.