CP1E-E@@D@-@ CP1E-N@@D@-@/NA20D@-@
Internal Memory in the CPU Units
CPU Unit Memory Backup Structure
The internal memory in the CPU Unit consists of built-in RAM and built-in EEPROM. The built-in RAM is used as execution memory and the built-
in EEPROM is used as backup memory.
CPU Unit
Built-in EEPROM
Backup memory
Built-in RAM
Execution Memory
Automatic backup
Read at startup
User Program Area
(Backup)
User Program Area
Area where data is backed up
even if the power supply is
interrupted for longer than the
back-up time of the built-in
capacitor.
Automatic backup
Read at startup
PLC Setup
PLC Setup
Area where data is cleared if
the power supply is
I/O Memory Areas
interrupted for longer than the
back-up time of the built-in
capacitor.
Backup using bit in Auxiliary Area
DM Area data read at startup
DM Area
DM Area
Data is retained even if the power
supply is interrupted for longer
than the backup time of the built-in
capacitor.
If a CP1W-BAT01 Battery (sold
separately) is mounted to an N/NA-type
CPU Unit, which is normally backed up
by a built-in capacitor, data will be
backed up by the battery.
●Precautions for Correct Use
Create a system and write the ladder programs so that problems will not occur in the system if the data in these area may be unstable.
• Data in areas such as the DM area (D), Holding Area (H), the Counter Present Values (C) and the status of Counter Completion Flags (C), which
is retained by the battery, may be unstable when the power supply is turned off (Except for the DM area that are retained by the built-in EEP-
ROM using the Auxilliary Area bit.)
• The error log, and clock data (N/NA-type CPU Unit only) in the Auxiliary Area will become unstable. Other words and bits in the Auxiliary Area
will be cleared to their default values.
The built-in capacitor’s backup time varies with the ambient temperature as shown in the following graph.
50 hours
CP1E E-type CPU Unit
40 hours
CP1E N/NA-type CPU Unit
25 hours
20 hours
9 hours
7 hours
25
40
60
Ambient temperature
13
OMRON [ OMRON ELECTRONICS LLC ]
