Installation manual

Publication 1747-RM001G-EN-P - November 2008
11-2 Understanding Interrupt Routines
User Fault Routine
Overview
The user fault routine gives you the option of preventing a processor
shutdown when a specific user fault occurs. The file is executed when any
recoverable or non-recoverable user fault occurs. The file is not executed for
non-user faults.
A fault routine is programmed in a program file other than 2. The program file
used is specified as the fault routine in word S:29 in the status file. More than
one user fault routine can exist. The example on page 11-5 shows how this can
be accomplished.
Faults are classified as recoverable and non-recoverable user faults, and
non-user faults.
Fixed SLC
5/01
SLC
5/02
SLC
5/03
SLC
5/04
SLC
5/05
••••
Table 11.2 Fault Classification
Non-User Fault Non-Recoverable User Fault Recoverable User Fault
The Fault Routine
does not execute.
The Fault Routine executes for 1
pass.
The Fault Routine may
clear the fault by clearing
bit S:1/13.
TIP
You may initiate a MSG instruction to another node to
identify the fault condition of the processor.
TIP
For SLC 5/02 processors: You must save your program
with test single step selected in order for S:20 and S:21 to be
activated.
For SLC 5/03 and higher processors: If your program
contains four message instructions with the Continuous
Operation (CO) bit set, the fault routine’s message
instruction is not executed.