8-11
8 Message Communications
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
8-2 Using CIP Message Communications
8
8-2-5 Preparing Derivative Data Types to Use CIP
Communications Instructions
To use CIP communications instructions, you must prepare derivative data type variables to input com-
munications parameter settings in advance. Refer to the NJ-series CPU Unit Software User’s Manual
(Cat. No. W501) for the specifications and setting procedures for the variables that are described in this
section.
A CIP communications instruction combines all of the objects in a request path into a single structure
variable.
Creating Structure Variables
To input a value into the structure variable of a CIP communications instruction, you must create a
user-defined variable with the same configuration in advance.
Example: Creating a Variable to Input Data to the CIPSend Instruction Array Variable Rq+Path
To create a variable in a variable table, select the pre-registered CIP communications instruction
data type _sREQUEST_PATH. This is a structure variable with the same configuration as Rq+Path.
Example:
8-2-5 Preparing Derivative Data Types to Use CIP Communications
Instructions
Providing the Structure Variables to Input Request Paths
AttributelD
InstancelD
ClasslD
Member
Rq+Path Data Type
Rq+Path
CIP communications instruction
Variable A
Create variable A with a _sREQUEST_PATH data type
with the same structure variable as Rq+Path.
Value
2
3
1
Select the same data type as Rq+Path for the
data type of variable A.
Data type
Variable name
Variable table