Power Off Operation - Omron NX Series Hardware User Manual

Process
Data check
Recording Power Turned ON and
Power Interrupted events
*1. Refer to the NJ/NX-series Troubleshooting Manual (Cat. No. W503) for information on the Power Supply Er-
ror, CPU Unit Error, Hardware Initialization Error, and System Initialization Error.
Operating Mode at Startup
The system will immediately enter RUN mode if RUN mode (default) is set as the startup operating
mode. The system will immediately enter PROGRAM mode if PROGRAM mode is set as the startup
operating mode.
•
RUN Mode Set as Startup Mode
Power supply
Operating mode
RUN indicator
5-1-2

Power OFF Operation

The NX-series Controller continues normal operation for a certain period of time when
a momentary power interruption occurs. This means that the NX-series Controller may
receive incorrect signals from external devices that are also affected by the power in-
terruption.
Accordingly, take suitable actions, such as external fail-safe measures and interlock
conditions, to monitor the power supply voltage of the external device as required.
A power OFF status is detected when the Unit power supply drops to the following voltage or lower or
when the following time has elapsed due to a momentary power interruption.
Momentary power inter-
ruption voltage
20.4 VDC or less
*1. A power OFF status may be detected when a momentary power interruption of 2 ms or less occurs consec-
utively.
NX-series NX502 CPU Unit Hardware User's Manual (W629)
The _RetainFail (Retention Failure Flag) system-defined variable
changes to TRUE when the values of variables for which the Re-
tain attribute was set to retain the values were not retained after
a power interruption.
The Power Turned ON and Power Interrupted events are record-
ed.
CPU Unit Startup
Time at Power ON
Startup RUN mode
Flashing Lit
Power OFF detection time
*1
2 ms min. to 4 ms max.
Description
•
PROGRAM Mode Set as Startup Mode
Power supply
CPU Unit Startup
Time at Power ON
Operating mode
RUN indicator
WARNING
5 Installation and Wiring
Startup PROGRAM mode
Flashing Not lit
5
5-3