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Exchanging Data with the CPU Unit Section 5-5
5-5 Exchanging Data with the CPU Unit
5-5-1 Outline of Data Exchange
Data is exchanged between the CPU Unit and the Analog Output Unit via the
Special I/O Unit Area (for data used to operate the Unit) and the Special I/O
Unit DM Area (for data used for initial settings).
I/O Refresh Data
Analog output setting values and other data used to operate the Unit are allo-
cated in the Special I/O Unit Area of the CPU Unit according to the unit num-
ber, and are exchanged during I/O refreshing.
Fixed Data
The Unit’s fixed data, such as the analog output signal ranges and the output
status when conversion is stopped, is allocated in the Special I/O Unit DM
Area of the CPU Unit according to the unit number, and is exchanged when
the power is turned ON or the Unit is restarted.
CJ-series CPU Unit
CJ1W-DA021/041/08V/08C Analog Output Unit
Special I/O Unit Area I/O Refresh Data
Analog outputs
DM (Data Memory) Area
I/O refresh
2000 + n x 10
2000 + n x 10 + 9
D20000 + n x 100
D20000 + n x 100 + 99
Fixed Data
:
:
10 
words
100 
words
Analog output 
ranges
Output status 
when conversion 
stopped
Power ON or 
Unit restart
Exchanges analog output 
values exchanged during 
data refresh.
Transmits fixed data such 
as conversion stop values 
and analog output ranges.
n: Unit number
See  Allocations for 
Normal Mode on 
page 193 for 
details.
See  DM Allocation 
Contents on 
page 190 for 
details.