Omron CJ - 08-2008 Operation Manual page 500

Power OFF Operation
1,2,3...
85% of the rated voltage or less (DC power supply: 80% or less for PD025, 90% or less for PD022)
Power supply
voltage
Power supply
voltage
Power supply
voltage
452
The following processing will be performed if power drops only momentarily
(momentary power interruption).
1. The system will continue to run unconditionally if the momentary power in-
terruption lasts less than 10 ms, i.e., the time it takes the minimum rated
voltage at 85% or less to return to 85% or higher is less than 10 ms.
Note When DC power supplies are used, less than 2 ms is required for the rated
voltage of a CJ1W-PD025 at 80% or less to return to 80% or higher or for the
rated voltage of a CJ1W-PD022 at 90% or less to return to 90% or higher.
2. A momentary power interruption that lasts more than 10 ms but less than
25 ms (when using a DC power supply, more than 2 ms but less than 5 ms
for CJ1W-PD025 and more than 2 ms but less than 10 ms for CJ1W-
PD022) is difficult to determine and a power interruption may or may not
be detected.
3. The system will stop unconditionally if the momentary power interruption
lasts more than 25 ms (when using a DC power supply, more than 5 ms for
CJ1W-PD025 and more than 10 ms for CJ1W-PD022).
Therefore, the time required to detect a power interruption is 10 to 25 ms
(when using a DC power supply, 2 to 5 ms for CJ1W-PD025 and 2 to 10 ms
for CJ1W-PD022) If operation stops under the conditions given in items 2 and
3 above, the timing used to stop operation (or the timing used to start execu-
tion of the Power OFF Interrupt Task) can be delayed by setting the Power
OFF Detection Delay Time (0 to 10 ms) in the PLC Setup. Operation, how-
ever, will always be stopped 10 ms after detecting a momentary power inter-
ruption regardless of the setting in the PLC Setup. The holding time for the
5-VDC outputs of CJ1W-PD022 Power Supply Units when a power interrup-
tion occurs is 1 ms, however, so bit 22515 (Power OFF Interrupt Task Disable
Bit) and bits 22500 to 22507 (Power OFF Detection Time (Power OFF Detec-
tion Delay Time) Bits) cannot be used.
10 ms
0 to 10 ms
(PD025/PD022:
0 to 2 ms)
Momentary power
interruption not
detected and op-
eration continues.
10 to 25 ms
(PD025: 2 to 5 ms,
PD022: 2 to 10 ms)
Operation will continue or
stop depending on
whether or not a
momentary power
interruption is detected.
Note The above timing chart shows an example when the power OFF detection
delay time is set to 0 ms.
25 ms
Time
25 ms and longer
(PD025: 5 ms, PD022: 10 ms)
Momentary power interruption detected
and operation stops.
Section 10-3