Omron CJ - 08-2008 Operation Manual page 503

Power OFF Operation
Note
W0.00
2. Set the Disable Setting for Power OFF Interrupts in A530 to A5A5 Hex to
enable disabling power interruption processing.
Note A530 is normally cleared when power is turned OFF. To prevent this,
the IOM Hold Bit (A50012) must be turned ON and the PLC Setup
must be set to maintain the setting of the IOM Hold Bit at Startup, or
the following type of instruction must be included at the beginning of
the program to set A530 to A5A5 Hex.
A20011
First Cycle Flag
3. Disable the Power OFF Interrupt Task in the PLC Setup.
With the above procedure, all instructions between DI(693) and EI(694) (or
END) will be completed (see note 1) before the Power OFF Interrupt is exe-
cuted even if the power interruption occurs while executing the instructions
between DI(693) and EI(694).
1. The protected instructions can be completed only when the time required
to complete execution is less than or equal to the processing time after
power interruption detection (10 ms − power interruption detection delay
time). If the instructions is not completed within this time, they will be inter-
rupted and the above processing will be performed.
2. If the Power OFF Interrupt Task is not disabled in the PLC Setup, the Power
OFF Interrupt Task will be executed, and the CPU Unit will be reset without
executing the protected instructions as soon as the power interruption is
detected.
3. If a power interrupt is detected while DI(693) is being executed, the CPU
Unit will be reset without executing the protected instructions.
4. The processing time after a power interruption is detected is 1 ms when a
CJ1W-PD022 is mounted.
Interrupt tasks disabled.
DI
Instructions that cannot be
interrupted when a power
interruption occurs
Interrupt tasks enabled.
EI
Set A530 to A5A5 Hex at the
MOV
beginning of the program to enable
#A5A5
disabling power interruption
A530
processing.
Section 10-3
Power interruption
confirmed.
Instructions executed here.
455