Omron Sysmac NX1P2-10 1 Series, User Manual

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8-6 Read and Write Services for Variables
This section shows services that specify the CIP object in the Request Path and access the CIP mes-
sage server function of the NJ/NX-series Controllers.
8-6-1 Read Service for Variables
Specify service code 4C hex to read the value of the variable that is specified by the request path.
Service code: 4C hex

Request Data Format
Request Path Data
Request Service Data
+0 Num of Element (L) UINT Specify the number of elements to read for an array variable.
+1 (H)
Response Service Data
Data Type USINT Data type of variable to read
AddInfo Length USINT Additional information: Field length in bytes
(AddInfo) Additional information: CRC value of structure
Actual data*
Variable name specification
*1. The actual data is stored in little-endian format.
Data Type Code for data type of variable to read. Refer to 8-7-1 Data Type Codes on page 8-87.
AddInfoLength The size of the AddInfo area is stored only when accessing a structure variable.
Set 02 hex for a structure variable. Otherwise, set 00 hex.
AddInfo The CRC code of the structure definition is stored only when accessing a structure vari-
able. In this case, the size of AddInfo will be 2 bytes.
Actual data The actual data is stored in little-endian format.
If 0001 hex is specified for an array, the actual data is stored in the same format as
when you access a variable with the data type of the elements of the array.
Response Codes
CIP
status
Meaning
Add
status
Cause
00 SUCCESS --- The service ended normally.
02 RESOURCE_UNAVAILABLE --- The internal processing buffer is not
available.
04 PATH_SEGMENT_ERROR --- The request path specification is not cor-
rect.
05 PATH_DESTINATION_UNKNOWN --- The variable specification is not correct.
0C OBJECT_STATE_CONFLICT 8010 Downloading, starting up
8011 There is an error in tag memory.
8 CIP Message Communications
8-83
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)
8-6
Read and W
rite Services for V
ariables
8
8-6-1
Read Service for V
ariables