Omron NJ501-1300 - A-4-2 Important Case Examples

Appendices
A-14
NJ-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)
When the object for a tag data link includes a structure variable, make sure that the locations in memory
of the structure variable members match between the NJ-series CPU Unit and the CPU Unit you need
to exchange data with. You need to be aware of the locations in memory of structure variable members
in the following cases.
z Reading and Writing Variables through CIP Messages or EtherNet/IP Tag Data
Links between an NJ-series CPU Unit and a CJ-series CPU Unit
The differences in memory configuration for structure variables between an NJ-series CPU Unit and
a CJ-series CPU Unit are shown below.
In this case, use the following solution.
Solution: Align the CJ-series and NJ-series memory locations.
Example: Insert members to adjust memory locations.
You must match both the memory locations and the data types.
You need to create the alignment members in both the CJ-series and NJ-series CPU Units.
A-4-2 Important Case Examples
Data Type Definitions
Name
Structure Y
a
b
c
Data type
STRUCT
DINT
INT
DINT
Bytes
a
b
c
CJ-series Structure Variable
CJ_
X
First byte
First byte + 4
First byte + 6
Variable Table
Name
Variable CJ_X
Data type
Structure Y
Data Type Definitions
Name
Structure Y
a
b
c
Data type
STRUCT
DINT
INT
DINT
Bytes
a
b
Not used.
c
NJ-series Structure Variable
NJ_X
First byte
First byte + 4
First byte + 6
First byte + 8
Variable Table
Name
Variable NJ_X
Data type
Structure Y
Data Type Definitions
Name
Structure
Y
a
b
b2
c
Data type
STRUCT
DINT
INT
INT
DINT
Bytes
a
b
b2
c
CJ-series Structure Variable
CJ_
X
First byte
First byte + 4
First byte + 6
First byte + 8
Variable Table
Name
Variable
CJ_X
Data type
Structure
Y
Data Type Definitions
Name
Structure
Y
a
b
b2
c
Data type
STRUCT
DINT
INT
INT
DINT
Bytes
a
b
b2
c
NJ-series Structure Variable
NJ_X
First byte
First byte + 4
First byte + 6
First byte + 8
Variable Table
Name
Variable
NJ_X
Data type
Structure
Y
Data Type Definitions
Name
Structure Y
a
b
c
Data type
STRUCT
DINT
INT
DINT
Bytes
a
b
c
CJ-series Structure Variable
CJ_
X
First byte
First byte + 4
First byte + 6
Variable Table
Name
Variable
CJ_X
Data type
Structure
Y
Data Type Definitions
Name
Structure Y
a
b
c
Data type
STRUCT
DINT
INT
DINT
Bytes
a
b
Not used.
c
NJ-series Structure Variable
NJ_X
First byte
First byte + 4
First byte + 6
First byte + 8
Variable Table
Name
Variable
NJ_X
Data type
Structure
Y
(2) Add the dummy variable b2 that you created in the
CJ-series CPU Unit to the NJ-series CPU Unit as well.
(1) Add a dummy member variable b2 that matches the
unused memory location on the NJ-series CPU Unit.
Make the following changes to align the memory
configurations in the NJ-series and CJ-series CPU Units.