Rockwell Automation 1768-L45S Compact GuardLogix Controllers - Manual (Page 108)

108 Rockwell Automation Publication 1768-UM002C-EN-P - April 2012
Chapter 8 Monitor Status and Handle Faults
Fault Codes
Table 31 shows the fault codes specific to Compact GuardLogix controllers. The
type and code correspond to the type and code displayed on the Major Faults tab
of the Controller Properties dialog box and in the PROGRAM object,
MAJORFAULTRECORD (or MINORFAULTRECORD) attribute.
The Logix5000 Controllers Major and Minor Faults Programming Manual,
publication
1756-PM014 , contains descriptions of the fault codes common to
Logix controllers.
Developing a Fault Routine If a fault condition occurs that is severe enough for the controller to shut down,
the controller generates a major fault and stops the execution of logic.
Depending on your application, you may not want all safety faults to shut down
your entire system. In those situations, you can use a fault routine to clear a
specific fault and let the standard control portion of your system continue to
operate or configure some outputs to remain ON.
The controller supports two levels for handling major faults:
• Program Fault Routine
• Controller Fault Handler
Both routines can use the GSV and SSV instructions as described on page 109 .
Program Fault Routine
Each program can have its own fault routine. The controller executes the
program’s fault routine when an instruction fault occurs. If the program’s fault
routine does not clear the fault, or if a program fault routine does not exist, the
controller proceeds to execute the controller fault handler, if one exists.
Table 31 - Major Safety Faults (Type 14)
Code Cause Status Corrective Action
01
Task watchdog expired. User task has not completed in a
specified period of time. A program error caused an infinite
loop, the program is too complex to execute as quickly as
specified, a higher priority task is keeping this task from
finishing. Nonrecoverable Clear the fault.
If a safety task signature exists, safety memory is re-initialized and the safety task
begins executing.
If a safety task signature does not exist, you must re-download the program to
allow the safety task to run.
02 An error exists in a routine of the safety task. Recoverable Correct the error in the user-program logic.
07 Safety task is inoperable.
This fault occurs when the safety logic is invalid, for example
a watchdog timeout occurred, or memory is corrupt. Nonrecoverable Clear the fault.
If a safety task signature exists, safety memory is re-initialized via the safety task
signature and the safety task begins executing.
If a safety task signature does not exist, you must download the program again to
allow the safety task to run.
08 Coordinated system time (CST) not found. Nonrecoverable Clear the fault. Configure a device to be the CST master.
ATTENTION: You must provide proof to your certifying agency that allowing
a portion of the system to continue to operate maintains safe operation.