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CIP services
Chapter 1
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
15
controller scoped tags is user selectable. If a tag’s External Access attribute is
set to
None
,
then the tag cannot be accessed from outside the controller.
For more information about external access to controller scoped tags see the
Logix 5000 Controllers I/O and Tag Data Programming Manual
, publication
For more information about tags and data types, see the
Controllers Design Considerations Reference Manual
, publication
See also
The Read tag, Write Tag, Read Tag Fragmented, Write Tag Fragmented, and
Read-Modify-Write Tag services require a service parameter that identifies
the data type of the tag being referenced. This tag type parameter is:
•
A 16-bit value for atomic tags
•
Two 16-bit values for structured tags
The value used for structures is a calculated value. For details, see
Tag type
service parameters for structures
.
The tag type values used for atomic tags and the resulting data size are
shown in the table shown in
Tag type service parameter values used with
Logix controllers
.
See also
Tag type service parameters for structures
Use this table for date types, tag type values, and size of transmitted data for
Logix controllers.
Data Type
Tag Type Value
Size of Transmitted Data
BOOL
0x0nc1
The BOOL value includes an additional field
(n) for specifying the bit position within the
SINT (n = 0-7).
1 byte
SINT
0x00C2
1 byte
INT
0x00C3
2 bytes
DINT
0x00C4
4 bytes
REAL
0x00CA
4 bytes
DWORD
0x00D3
4 bytes
LINT
0x00C5
8 bytes
bytes = Multi-byte data values are transmitted low-byte first
Tag type service parameter
Tag type service parameter values
used with Logix controllers