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Overview of I/O Memory Area Section 4-1
4-1 Overview of I/O Memory Area
4-1-1 I/O Memory Area
This region of memory contains the data areas that can be accessed as
instruction operands. I/O memory includes the CIO Area, Work Area, Holding
Area, Auxiliary Area, DM Area, Timer Area, Counter Area, Task Flag Area,
Data Registers, Index Registers, Condition Flag Area, and Clock Pulse Area.
Instruction
I/O Memory
Area Size Range Task usage Allocation Bit
access
Word
access
Access Change
from CX-
Programmer
Forcing
bit
status
Read Write
CIO
Area
I/O Area Input
Area
272 bits
(17 words)
CIO 0 to
CIO 16
Shared by
all tasks
CP1H CPU
Units and
CP-series
Expansion
Units or
Expansion I/O
Units
OK OK OK OK OK OK
Output
Area
272 bits
(17 words)
CIO 100
to CIO
116
OK OK OK OK OK OK
Built-in ana-
log I/O
Areas
(XA CPU
Units only)
Built-in
Analog
Input
Area
4 words CIO 200
to CIO
203
Built-in analog
input terminals
OK OK OK OK OK OK
Built-in
Analog
Output
Area
2 words CIO 210
to 211
Built-in analog
output termi-
nals
OK OK OK OK OK OK
Data Link Area 3,200 bits
(200
words)
CIO 1000
to CIO
1199
Data Links OK OK OK OK OK OK
CPU Bus Unit Area 6,400 bits
(400
words)
CIO 1500
to CIO
1899
CPU Bus
Units
OK OK OK OK OK OK
Special I/O Unit Area 15,360
bits (960
words)
CIO 2000
to CIO
2959
Special I/O
Units
OK OK OK OK OK OK
Serial PLC Link Area 1,440 bits
(90 words)
CIO 3100
to CIO
3189
Serial PLC
Links
OK OK OK OK OK OK
DeviceNet Area 9,600 bits
(600
words)
CIO 3200
to CIO
3799
DeviceNet
Masters using
fixed alloca-
tions
OK OK OK OK OK OK
Work Area 4,800 bits
(300
words)
37,504
bits (2344
words)
CIO 1200
to CIO
1499 CIO
3800 to
CIO 6143
--- OK OK OK OK OK OK
Work Area 8,192 bits
(512
words)
W000 to
W511
--- OK OK OK OK OK OK
Holding Area 8,192 bits
(512
words)
H000 to
H511
(Note 1)
--- OK OK OK OK OK OK
Auxiliary Area 15,360
bits (960
words)
A000 to
A959
--- OK --- OK Read-
only:
A000 to
A447
Read-only:
A000 to
A447
No
Read/
write:A44
8 to A959
Read/write:
A448 to
A959
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