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Exchanging Data with the CPU Unit Section 3-5
• If there is noise interference from power lines (if, for example, the power
supply is shared with electrical welding devices or electrical discharge
machines, or if there is a high-frequency generation source nearby) install
a noise filter at the power supply input area.
3-5 Exchanging Data with the CPU Unit
3-5-1 Outline of Data Exchange
Data is exchanged between the CPU Unit and the CJ1W-AD041-V1/081-V1
Analog Input 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 input conversion values, which are used as data for Unit operation, are
allocated in the Special I/O Unit Area of the CPU Unit according to the unit
number, and are exchanged during I/O refreshing.
Fixed Data
The Unit’s fixed data, such as the analog input signal ranges and the number
of operational mean value buffers 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.
The conversion time and resolution can be set, along with the operation
mode.
CJ-series CPU Unit
CJ1W -AD041-V1/081-V1 Analog Input Unit
Special I/O Unit Area
I/O Refresh Data
Analog inputs
Analog inputs
DM (Data Memory) Area
Input signal range
Number of opera-
tional mean value 
buffers
I/O refresh
Power ON or 
Unit restart
Exchanges analog input val-
ues during data refresh. 
Transmits fixed data such 
as analog input signal 
ranges and number of 
operational mean value 
buffers..
2000 + n x 10
2000 + n x 10 + 9
D20000 + n x 100
D20000 + n x 100 + 99
10 
w
ords
100 
words
Fixed Data
:
:
n: Unit number
See 3-5-5 I/O 
Refresh Data 
Allocations for 
details.
See 3-5-4 Fixed 
Data Allocations 
for details.
Conversion time/ 
resolution and 
operating mode