5-11
5 I/O Memory
CP1E CPU Unit Software User’s Manual(W480)
5-5 Data Memory Area (D)
5
5-5 Data Memory Area (D)
This data area is used for general data storage and manipulation and is accessible only by word (16
bits).
These words retain their contents when the PLC is turned ON or the operating mode is switched
between PROGRAM mode and RUN or MONITOR mode.
Some words in the DM Area can be saved to the built-in EEPROM backup memory using Auxiliary Area
bits. These words are specifically referred to as the backed up words in the DM Area.
Precautions for Safe Use
With an E-type CPU Unit or with an N/NA-type CPU Unit without a Battery, the contents of the
DM Area (D) *, Holding Area (H), the Counter Present Values (C), the status of Counter Comple-
tion Flags (C), and the status of bits in the Auxiliary Area (A) related to clock functions may be
unstable when the power supply is turned ON.
* This does not apply to areas backed up to EEPROM using the DM backup function.
If the DM backup function is being used, be sure to refer to 3-2-4 Initializing I/O Memory at Star-
tup for details.
• E-type CPU Units have DM Area addresses ranging from D0 to D2047.
Of these, D0 to D1499 can be backed up in backup memory (built-in EEPROM).
• N/NA-type CPU Units have DM Area addresses ranging from D0 to D8191.
Of these, D0 to D6999 can be backed up in backup memory (built-in EEPROM).
Overview
Notation
Range
D 200
Word number: 200
I/O memory area designator: D
· N30/40/60 or NA20 CPU Unit
D1300
D1200
D1399
D0
D1299
· N14/20 CPU Unit
D1300
D1299
D8191
D1400
D8191
D1199
· All CPU Units Regardless
of I/O Capacity
D2047
D0
to
to
to
D1200
D0
D1199
to
to
to
to
to
to
to
[ E-type CPU Unit ] [ N/NA-type CPU Unit ]
D6999
D7000
D6999
D7000
D1499
D1500
Words that can be
backed up to backup
memory
Words that can be backed
up to backup memory
DM Fixed Allocation Words
for the Modbus-RTU Easy
Master (for Built-in RS-
232C Port)
DM Fixed Allocation Words
for the Modbus-RTU Easy
Master (for Built-in RS-232C
Port)
DM Fixed Allocation Words
for the Modbus-RTU Easy
Master (for Serial Option
Port)
Words that can be backed
up to backup memory
to
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