Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 294)

Preface MicroLogix 1000 Programmable Controllers User Manual
B–6
Address Bit Classification Description
S:1/9 Startup
Protection
Fault Static
Configuration When this bit is set and power is cycled while
the controller is in the REM Run mode, the
controller executes the user-fault routine prior
to the execution of the first scan of your
program. You have the option of clearing the
Major Error Halted bit S:1/13 to resume
operation in the REM Run mode. If the
user-fault routine does not reset bit S:1/13, the
fault mode results.
Program the user-fault routine logic
accordingly. When executing the startup
protection fault routine, S:6 (major error fault
code) will contain the value 0016H.
S:1/10 to
S:1/11 Reserved NA NA
S:1/12 Run Always Static
Configuration When set, this bit causes the controller to clear
S:1/13 before attempting to enter RUN mode
when power is applied or if an unexpected
reset occurs. If this bit is not set, the controller
powers up in the previous mode it was in
before losing power, unless the controller was
in REM test mode. If the controller was in
REM test mode when power was removed, the
controller enters REM program mode when
power is applied.
This bit overrides any faults existing at power
down.
Setting the Run Always bit
causes the controller to enter
the REM Run mode if an
unexpected reset occurs,
regardless of the mode that the
controller is in before the reset
occurred. Unexpected resets
may occur due to
electromagnetic noise, improper
grounding, or an internal
controller hardware failure. Make
sure your application is designed
to safely handle this situation.
!