Omron SYSMAC CS/CJ Series Programming Manual page 194

Interrupt Tasks
Example: If the power OFF detection delay time is set to 4 ms in PLC Setup,
then execution time must be less than 10 minus 4 ms, or 6 ms.
Power OFF interrupt task
Note A power OFF condition is recognized when the power supply falls below 85%
of the minimum rated voltage (80% for DC power supplies), and the time it
takes before the power OFF interrupt task actually executes is the default
power OFF detection time (10 to 25 ms for AC power supplies and 2 to 5 ms
for DC power supplies) plus the power OFF detection delay time in the PLC
Setup (0 to 10 ms). Cyclic tasks will be executed for this amount of time.
Power supply < 85% of the
minimum rated voltage (80%
for DC power supplies)
Cyclic task
Default power OFF
detection time plus
power OFF detection
delay time
Note Be sure that the power OFF interrupt task can be executed in less than 10 ms
minus the power OFF detection delay time set in the PLC Setup. Any remain-
ing instructions will not be executed after this time has elapsed. The power
OFF interrupt task will not be executed if power is interrupted during online
editing. In addition to the instructions that cannot be used in any interrupt task
(refer to the Programming Manual for details), the following instructions can-
not be used in the power OFF interrupt task: READ DATA FILE: FREAD(700),
WRITE DATA FILE: FWRIT(701), NETWORK SEND: SEND(090), NETWORK
RECEIVE: RECV(098), DELIVER COMMAND: CMND(490), TRANSMIT:
TXD(236), RECEIVE: RXD(235), and PROTOCOL MACRO: PMCR(260).
Less than 10 ms minus the
power OFF detection delay time
The default setting is 10 ms max.
Power OFF CPU reset
recognized (force end)
Power OFF interrupt task
10 ms minus the power
OFF detection delay time
Section 4-3
Stop
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