Cip Message Structure For Accessing Cip Objects; Cip Message Structure For Accessing Variables - Omron Sysmac NJ-series User Manual

8 CIP Message Communications
8-3-1

CIP Message Structure for Accessing CIP Objects

This section shows how to specify messages to access CIP objects.
The CIP objects to access are expressed by connecting the segments that are defined in the CIP Com-
mon specifications in the request path field in a CIP explicit message.
Example: Performing the Reset service (0x05) to the Instance (01 hex) of the Identity object (class: 01
hex)
CIP Explicit Message (Request)
Service
Code
(0x05)
Specify the performed service
code. Refer to 8-5 CIP Object
Services for information about
the service codes.
8-3-2

CIP Message Structure for Accessing Variables

This section shows how to specify messages to access variables.
The variables to access are given by connecting the segments that are defined in the CIP Common
specifications so that explicit message can be set in the request path field.
The following elements are combined to make the specification.
Specifying the variable to access: The elements are stored in the CIP segments and then joined to
make the message.
Example: Reading the Present Value of One Member of the VarAA.MemB[1.2] Structure Variable
Example for Using the CIP Read Data Service for a Variable Object
CIP Explicit Message for a Request
Service
Code
(4C hex)
Refer to 8-6 Read and Write
Services for Variables for infor-
mation about the service codes.
8-40
Request
[1]
Path Length
(20 01)
(02)
Logical Segment
(Class ID)
Specify the Class ID and
Instance ID to access.
Request
"VarAA"
Path Length
(91 05 45 61 72 41 41 00)
(09)
ANSI Extended Symbol Segment
Refer to 8-4-5 Specifying Vari-
able Names in Request Paths
for information about how to
specify variables names.
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User's Manual (W506)
Request Path
[2]
(24 01)
Logical Segment
(Instance ID)
Specify the Request Data
according to the service.
Request Path
"MemB"
(91 04 4D 65 6D 42)
Logical Segment
(Member ID)
Request
Service
Data
(num of
elem)
Request
Service
Data
[1] [2]
(28 01) (28 02)
(num of
elem)
Refer to 8-7 Variable Data Types
for details about how to specify
data formats.