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Creating I/O Tables Section 8-2
To solve this problem, the CX-Programmer had to be connected to the CPU
Unit onsite to recreate the I/O tables or to delete the I/O tables to enable using
the automatic I/O allocation at power ON method.
8-2 Creating I/O Tables
Although the automatic I/O allocation at startup method can be used for CJ-
series PLCs, I/O tables must be created and transferred to the CPU Unit in
cases like the following:
• To provide a record of the current Unit configuration to prevent it from
being changed.
• To reserve words for future use when Units are added to the PLC.
• To set the first word on the CPU Rack or Expansion I/O Racks.
• To allocate specified words to specific Units.
Once I/O tables are transferred to the CPU Unit, it saves them at the I/O allo-
cation status, and each time the power supply is turned ON, the CPU Unit
compares the contents of the I/O tables with the Units actually mounted to
verify the Unit configuration. Operation starts when the Unit configuration is
verified, but a fatal error occurs if a discrepancy is found.
When a Memory Card is used, the I/O tables are saved as one of the parame-
ter files and can be used as a parameter file for automatic transfer at power
ON.
8-2-1 Creating, Editing, and Transferring I/O Tables
When the CX-Programmer or a Programming Console is used to create I/O
tables in the CPU Unit, the CPU Unit will check Unit connections when the
power supply is turned ON and then start operation. There are two ways to
register the I/O tables in the CPU Unit: Create them according to the Units
actually connected in the PLC by using the online I/O table creation operation
from the CX-Programmer or a Programming Console, or edit the I/O tables
offline on the CX-Programmer and then transfer them to the CPU Unit.
CX-Programmer
Memory Card
Mis-match
(See note.)
Mail
Create program files for automatic
transfer at power ON
(AUTOEXEC.OBJ) and parameter
files for automatic transfer at
power ON (AUTOEXEC.STD).
Office Remote site
Units are mounted
I/O not allocated according to settings in mounted Units.
User-set I/O allocation
Program file for automatic
transfer at power ON
(AUTOEXEC.OBJ)
Parameter file for automatic
transfer at power ON
(AUTOEXEC.STD)
Note: The parameter file for automatic transfer
at power ON (AUTOEXEC.STD) is
present, and this file is used to allocated
I/O instead of the I/O allocations in the
mounted Units.
CJ-series CPU Unit
Automatic I/O allocation at startup
Units not mounted.
Program file for automatic
transfer at power ON
(AUTOEXEC.OBJ)
Parameter file for automatic
transfer at power ON
(AUTOEXEC.STD)
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