Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 380)

Chapter 20
Troubleshooting Your System
20–12
2. Clear the fault.
DEL
A L L
F L T : 0 0 2 0 H
C L E A R I N G . . . . .
After the fault is cleared, the HHP returns to the screen that was displayed
prior to accessing the fault display.
Automatically Clearing Faults
You can automatically clear a fault when cycling power to the controller by
setting either one or both of the following status bits in the status file:
•
Fault Override at Powerup bit (S1/8)
•
Run Always bit (S1/12)
!
ATTENTION: Clearing a fault using the Run Always bit
(S1/12) causes the controller to immediately enter the RRUN
mode. Make sure you fully understand the use of this bit before
incorporating it into your program. Refer to page B–4 for more
information. Also refer to chapter 5 for information pertaining to
retentive data.
Refer to appendix B for more information on status bits.
Important: You can declare your own application-specific major fault by
writing your own unique value to S6 and then setting bit S1/13
to prevent reusing system defined codes. The recommended
values for user defined faults is FF00 to FF0F.
Using the Fault Routine
The occurrence of recoverable or non-recoverable user faults causes file 3 to
be executed. If the fault is recoverable, the subroutine can be used to correct
the problem and clear the fault bit S1/13. The controller then continues in
the RRUN mode.
The subroutine does not execute for non-user faults. The user-fault routine is
discussed in chapter 7.