Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 246)

Publication 1785-UM012D-EN-P - July 2005
15-8 Preparing Fault Routines
6. If the controller finds a match, the FSC instruction sets the found (.FD)
bit in the specified control structure.
7. Use a MOV instruction to clear the fault in S:11. In the following figure,
#N10:0 is the reference file.
Example of Comparing a Major Fault Code with a Reference
MOV
MOVE
Source
Dest S:11
0
RES
R6:0
] [
R6:0
FD
Remainder of fault routine follows
TND
EN
FSC
FILE SEARCH/COMPARE
Control
Length
Position
Mode
R6:0
20
0
ALL
DN
ER
Expression
S:12 = #N10:0
U
R6:0
IN
If the Fault Routine Then the Controller
clears S:11 returns to the program file and
resumes program execution.
does not clear S:11 executes the rest of the fault routine
and then faults
IMPORTANT
If the fault routine clears the major fault, the controller
completes the fault routine and returns to the next
instruction in the program file that follows the one that
contained the faulted instruction.
The remainder of the rung is executed and it appears that
the fault never occurred. The fault routine execution
continues until you correct the cause of the fault.