Omron CJ2 CPU UNIT SOFTWARE User Manual page 374

10 CPU Unit Functions
Operations after Power Is Interrupted during Automatic Backup
Automatic backup timing
While a program is being trans-
ferred
During online editing
While the PLC Setup is being trans-
ferred, the I/O tables are being
transferred, the I/O tables are being
created or cleared, the routing
tables is being transferred, or Spe-
cial I/O Unit settings are being
transferred.
• If the power is turned OFF when there is a Battery installed in the CPU Unit and when only ladder
tasks are being edited online, the status prior to the power interruption will be restored the next time
the power is turned ON. Be careful, however, of the following points.
• More time will be required to start the CPU Unit.
• Even if there is a Battery in the CPU Unit, always be sure that the backup operation has been
completed before turning OFF the power supply if the CPU Unit will be left unpowered for an
extended period of time.
• The amount of time required to back up data (the time the BKUP indicator will be lit) will depend on
the size of the user program, as shown in the following table.
User program size
100 Ksteps
250 Ksteps
400 Ksteps
Note The BKUP indicator will be lit when power is supplied to the CPU Unit.
Precautions for Correct Use Precautions for Correct Use
• Automatically back up the user program and parameter data to flash memory when they are
written to the CPU Unit. I/O memory (including the DM, EM, Holding, and Auxiliary Areas),
however, is not written to flash memory. The DM, EM, and Holding Areas can be held during
power interruptions with a battery. If there is a battery error, the contents of these areas may
not be accurate after a power interruption. If the contents of the DM, EM, Holding, and Auxil-
iary Areas are used to control external outputs, prevent inappropriate outputs from being made
whenever the Battery Error Flag (A402.04) is ON.
• A backup memory error (non-fatal) will occur if an error in the CPU Unit backup memory is
detected. If this error occurs, data will not be restored the next time the power supply is turned
ON, and a memory error may occur. Therefore, it is recommended to save the data before
turning OFF the power.
10-40
Applicable data
User program
User program:
• Ladder tasks
User program:
• ST tasks
• SFC tasks
• FB definitions
• SFC actions and transitions
Parameters
Backup processing time
MONITOR mode
20 s (cycle time of 3 ms)
47 s (cycle time of 7 ms)
75 s (cycle time of 11 ms)
Operation after power interrup-
tion
• The data will be lost.
• A memory error will occur the
next time the power is turned ON.
• The changes made during online
editing will be reflected the next
time the power is turned ON. (If
there is no Battery, however, the
changes will not be reflected and
a memory error will occur.)
• The contents of the online editing
will be lost.
• The data will be lost.
• A memory error will occur the
next time the power is turned ON.
PROGRAM mode
3 s
6 s
10 s
CJ2 CPU Unit Software User's Manual