Omron CJ2 - 02-2010 User Manual page 227

DM Area Allocations to Special I/O Units and CPU Bus Units
Parts of the DM Area are allocated to Special I/O Units and CPU Bus Units for functions, such as initial
Unit settings. These words can be used for general data storage if the corresponding Unit is not used in
the PLC.
The timing for data transfers is different for these Units, but may occur at any of the three following
times.
• Transferring data when the PLC's power is turned ON or the Unit is restarted
• Transferring data once each cycle
• Transferring data when required
Refer to the Unit's operation manual for details on data transfer timing.
CJ2 CPU Unit Software User's Manual
Word
D0
D20000
DM Area words for Special I/O Units
100 words/Unit
D29599
D30000
DM Area words for CPU Bus Units
100 words/Unit
D31599
D32767
6 I/O Memory Areas
6-25
6