A-5-1 Power Off Operation; A-5 Operation For Power Interruptions - Omron CJ2 CPU UNIT SOFTWARE User Manual

Appendices
A-5 Operation for Power Interruptions
A-5-1 Power OFF Operation
The following processing is performed if CPU Unit power is turned OFF. Power OFF processing will be
performed if the power supply falls below 85% (80% for CJ1W-PD025 DC Power Supply Units or 90%
for CJ1W-PD022 DC Power Supply Units) of the minimum rated voltage while the CPU Unit is in RUN
or MONITOR mode.
1
The CPU Unit will stop.
2
All outputs from Output Units will be turned OFF.
Note 1 All outputs will turn OFF regardless of the status of the IOM Hold Bit or the setting of the IOM Hold Bit at
startup in the PLC Setup.
2 85% of the rated voltage for AC Power Supply Unit:
100 VAC:85 VAC
200 VAC:170 VAC
100 to 240-V input (wide range): 85 VAC
3 80%/90% of the rated voltage for DC Power Supply Unit:
CJ1W-PD025: 19.2 VDC
CJ1W-PD022: 21.6 VDC
Momentary Power Interruptions
The following processing will be performed if power drops only momentarily (momentary power inter-
ruption).
• The system will continue to run unconditionally if the momentary power interruption 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.
• 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.
• The system will stop unconditionally if the momentary power interruption lasts 25 ms or longer (when
using a DC power supply, 5 ms or longer for CJ1W-PD025 and 10 ms or longer for CJ1W-PD022).
Therefore, the time required to detect a power interruption is 10 to 25 ms (when using a DC power sup-
ply, 2 to 5 ms for CJ1W-PD025 and 2 to 10 ms for CJ1W-PD022). If operation stops under the condi-
tions given in items 2 and 3 above, the timing used to stop operation (or the timing used to start
execution 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. The holding time for the 5-VDC outputs of CJ1W-PD022 Power
Supply Units when a power interruption occurs is 1 ms, however, so the Power OFF Interrupt Task Dis-
able and Power OFF Detection Time parameters cannot be used.
A-166 CJ2 CPU Unit Software User's Manual