Rockwell Automation Allen-Bradley Logix 5000 Series Owner's manual

Programming Manual
Logix 5000 Controllers Data Access
1756 ControlLogix, 1756 GuardLogix, 1769 CompactLogix, 1769 Compact GuardLogix, 1789
SoftLogix, 5069 CompactLogix, 5069 Compact GuardLogix, Studio 5000 Logix Emulate

Important user information
Read this document and the documents listed in the additional resources section about installation, configuration, and operation of this
equipment before you install, configure, operate, or maintain this product. Users are required to familiarize themselves with installation and
wiring instructions in addition to requirements of all applicable codes, laws, and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to be carried
out by suitably trained personnel in accordance with applicable code of practice. If this equipment is used in a manner not specified by the
manufacturer, the protection provided by the equipment may be impaired.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or
application of this equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements
associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the
examples and diagrams.
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in this manual.
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WARNING: Identifies information about practices or circumstances that can causean explosion in a hazardous environment, which may lead to
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Trademarks not belonging to Rockwell Automation are property of their respective companies.

Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 3
Summaryof Changes
This manual includes new and updated information. Use these reference
tables to locate changed information.
Grammatical and editorial style changes are not included in this summary.
Global changes
None in this release.
New or enhanced features
Subject Reason
Tag type service parameters for structure on
page 38
Added link to the Rockwell Automation Type Encoding of Logix
Structures in CIP Data Table R/W document.

Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 5
Tableofcontents
Studio 5000 environment................................................................................ 9
Additional resources ....................................................................................... 9
Legal notices................................................................................................. 10
Chapter 1
CIP Services Overview................................................................................. 13
CIP Data Types ...................................................................................... 13
Atomic data type sizes ..................................................................... 14
Logix 5000 data...................................................................................... 14
Tag type service parameter .................................................................... 15
Tag type service parameter values used with Logix controllers...... 15
Analysis.................................................................................................. 16
Segment Encoding.................................................................................. 16
Logical Segments............................................................................. 16
Symbolic Segments ......................................................................... 17
CIP Service Request/Response Format.................................................. 17
Services Supported by Logix 5000 Controllers............................................ 18
Read Tag Service ................................................................................... 20
Example Using Symbolic Segment Addressing .............................. 20
Example Using Symbol Instance Addressing.................................. 21
Read Tag Service Error Codes......................................................... 21
Read Tag Fragmented Service ............................................................... 22
Example Using Symbolic Segment Addressing .............................. 22
Example Using Symbol Instance Addressing.................................. 24
Read Tag Fragmented Service Error Codes .................................... 26
Write Tag Service................................................................................... 27
Example Using Symbolic Segment Addressing .............................. 27
Example Using Symbol Instance Addressing.................................. 27
Write Tag Service Error Codes........................................................ 28
Write Tag Fragmented Service .............................................................. 28
Example Using Symbolic Segment Addressing .............................. 29
Example Using Symbol Instance Addressing.................................. 31
Write Tag Fragmented Service Error Codes.................................... 33
Read Modify Write Tag Service ............................................................ 33
Service Request Parameters............................................................. 33
Example ........................................................................................... 34
Read Modify Write Tag Service Error Codes ................................. 34
Multiple Service Packet Service...................................................... 35
Example ........................................................................................... 35
Logix Data Structures ................................................................................... 36
Work with Data Structures..................................................................... 37
Tag type service parameters for structure .............................................. 38
Summary of Changes
Preface
CIP services

Table of contents
6Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Chapter 2
How tags are organized in the controller ...................................................... 41
Symbol object......................................................................................... 42
Template object...................................................................................... 42
Create and maintain a symbol object list ...................................................... 44
Step 1: Find user-created controller scope tags in a Logix 5000 controller . 45
Retrieve all symbol object instances ...................................................... 45
Example of retrieving the first group of tags ......................................... 46
Analysis.................................................................................................. 47
Continue the retrieval process.......................................................... 47
Step 2: Isolate user-created tags from system tags/identifying structured
tags................................................................................................................ 49
Symbol Type Attribute........................................................................... 49
Eliminate tags by applying rules...................................................... 50
Step 3: Determine the structure makeup for a specific structure.................. 51
Example of reading template attributes.................................................. 52
Analysis.................................................................................................. 53
Structure data format ....................................................................... 54
Contents of the member information ............................................... 54
Example of retrieving member information .................................... 55
Example ........................................................................................... 55
More about BOOLS in UDTs.......................................................... 57
Step 4: Determine the data packing of the members of a structure when
accessed as a whole ...................................................................................... 57
Example of reading an entire structure................................................... 58
Step 5: Determine when the tags list and structure information need
refreshing ...................................................................................................... 59
How to detect changes............................................................................ 59
Chapter 3
Atomic Members of Predefined Data Types ................................................ 63
Example 1 (Symbolic Segment Addressing Method) ............................ 63
Example 2 (Symbol Instance Addressing Method)................................ 64
Example 3 (Symbolic Segment Addressing Method) ............................ 64
Example 4 (Symbolic Segment Addressing Method) ............................ 65
Example 5 (Symbol Instance Addressing Method)................................ 65
Example 6 (Symbolic Segment Addressing Method) ............................ 66
Example 7 (Symbolic Segment Addressing Method) ............................ 67
Example 8 (Both Addressing Methods) ................................................. 67
Example 9 (Both Addressing Methods) ................................................. 68
Example 10 (Symbolic Segment Addressing Method) with BOOLs..... 68
Access User-Defined Structures ................................................................... 69
Example 1............................................................................................... 70
Example 2............................................................................................... 70
Example 3............................................................................................... 71
Example 4............................................................................................... 71
Example 5............................................................................................... 72
Example 6............................................................................................... 73
CIP Services and User-created
Tags
CIP Addressing Examples

Table of contents
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 7
Chapter 4
Unconnected Messaging (UCMM) through PCCC ...................................... 75
Connected Explicit Messages through PCCC............................................... 76
Fragmentation Protocol................................................................................. 78
Chapter 5
Supported Subset of PCCC Commands........................................................ 81
Initial Fields of All PCCC Commands ......................................................... 82
PLC-2 Communication Commands.............................................................. 83
Unprotected Read (CMD=01, 41; FNC not present) ............................. 83
Protected Write (CMD=00, 40; FNC not present) ................................. 84
Unprotected Write (CMD=08, 48; FNC not present)............................. 84
Protected Bit Write (CMD=02, 42; FNC not present) ........................... 84
Unprotected Bit Write (CMD=05, 45; FNC not present)....................... 85
PLC-5 Communication Commands.............................................................. 85
Addressing examples.............................................................................. 86
Read Modify Write N (CMD=0F, 4F; FNC=79) ................................... 87
Typed Read (CMD=0F, 4F; FNC=68)................................................... 88
Typed Write (CMD=0F, 4F; FNC=67) .................................................. 88
Word Range Read (CMD=0F, 4F; FNC=01)......................................... 88
Word Range Write (CMD=0F, 4F; FNC=00)........................................ 89
Bit Write (CMD=0F, 4F; FNC=02) ....................................................... 89
SLC Communication Commands ................................................................. 90
SLC Protected Typed Logical Read with 3 Address Fields (CMD=0F,
4F; FNC=A2) ......................................................................................... 90
SLC Protected Typed Logical Write with 3 Address Fields(CMD=0F,
4F, FNC=AA) ........................................................................................ 91
SLC Protected Typed Logical Read with 2 Address Fields (CMD=0F,
4F; FNC=A1) ......................................................................................... 91
SLC Protected Typed Logical Write with 2 Address Fields (CMD=0F,
4F; FNC=A9) ......................................................................................... 92
CIP Over the Controller Serial
Port
PCCC Commands
Index

Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 9
Preface
Before using this document:
•Have a thorough understanding of CIP and EtherNet/IP.
•Have purchased a copy of the pertinent volumes of the CIP Networks
Library.
•Be properly licensed through ODVA to use the CIP technology.
For more information on the CIP Networks Library and CIP technologies,
contact ODVA at http://www.odva.org/.
The Studio 5000 Automation Engineering & Design Environment®
combines engineering and design elements into a common environment. The
first element is the Studio 5000 Logix Designer® application. The Logix
Designer application is the rebranding of RSLogix 5000® software and will
continue to be the product to program Logix 5000™ controllers for discrete,
process, batch, motion, safety, and drive-based solutions.
The Studio 5000® environment is the foundation for the future of
Rockwell Automation® engineering design tools and capabilities. The Studio
5000 environment is the one place for design engineers to develop all
elements of their control system.
These documents contain additional information concerning related
Rockwell Automation products.
Resource Description
Industrial Automation Wiring and Grounding Guidelines,
publication 1770-4.1 Provides general guidelines for installing a Rockwell
Automation industrial system.
Product Certifications webpage, available at
http://ab.rockwellautomation.com
Provides declarations of conformity, certificates, and other
certification details.
Studio 5000 environment
Additional resources

Preface
10 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
View or download publications at
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technical documentation, contact the local Rockwell Automation distributor
or sales representative.
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You can view the Rockwell Automation End-User License Agreement
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Alternately, obtain complete Corresponding Source code by contacting
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I/O, ControlLogix, CompactLogix, DCM, DH+, Data Highway Plus,
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Guard I/O, High Performance Drive, Integrated Architecture, Kinetix,
Logix5000, Logix 5000, Logix5550, MicroLogix, DeviceNet, EtherNet/IP,
Legal notices

Preface
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 11
PLC-2, PLC-3, PLC-5, PanelBuilder, PowerFlex, PhaseManager, POINT
I/O, PowerFlex, Rockwell Automation, RSBizWare, Rockwell Software,
RSEmulate, Historian, RSFieldbus, RSLinx, RSLogix, RSNetWorx for
DeviceNet, RSNetWorx for EtherNet/IP, RSMACC, RSView, RSView32,
Rockwell Software Studio 5000 Automation Engineering & Design
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This product is warranted in accordance with the product license. The
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This document is current as of the time of release of the product; however,
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Contact Rockwell
Customer Support Telephone — 1.440.646.3434

Preface
12 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Online Support — http://www.rockwellautomation.com/support/

Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 13
Chapter 1
CIP services
Communicating with Logix 5000 controllers require using CIP explicit
messaging. This chapter describes the subset of the CIP explicit messaging
constructs for understanding the service explanations that follow.
See also
CIP services overview on page 13
Tag type service parameter on page 15
Analysis on page 16
Segment Encoding on page 16
CIP Service Request/Response Format on page 17
Before using CIP services, review introductory information:
•CIP data types
•Logix 5000 data
•Tag Type Service parameter
•Segment encoding
•CIP Service Request/Response format
Data type information is very important in all aspects of CIP communication.
The type information is used for reading, writing, and, if necessary,
deciphering structures. The Logix 5000 controller supports these data types.
•Atomic. A bit, byte, 16-bit word, or 32-bit word, each of which stores
a single value. (CIP refers to these as Elementary Data Types.)
•Structure. A grouping of different data types that functions as a single
unit and serves a specific purpose. Depending on the needs of the
application, create additional structures, which are referred to as
user-defined structures.
•Array. A sequence of elements, each of which is the same data type.
CIP Services Overview
CIP Data Types

Chapter 1
CIP services
14 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
•Define data in one, two, or three dimensions, as required (one
dimension is the most common).
•Use atomic or structure data types.
Data in the controller is organized as tags. The tags come in two basic types:
atomic and structure. Atomic types can be arrayed or singular, and are very
easy to work with. Structure types provide a great deal of flexibility, but are
more challenging to access. See the Atomic data type sizes table for details.
See also
CIP services overview on page 13
Atomic data type sizes on page 14
Logix 5000 data on page 14
Use the atomic data type sizes table for the data type value to use to store a
bit.
To store a Use this data type
Bit BOOL
Bit array DWORD (32-bit boolean array)
8-bit integer SINT
16-bit integer INT
32-bit integer DINT
32-bit float REAL
64-bit integer LINT
The Logix 5000 controller stores data in tags, in contrast to a PLC-5 or SLC
controller, which stores data in data files. Logix 5000 tags have these
properties:
•Name that identifies the data:
•Up to 40 characters in length.
•Scope:
•Controller (global), accessed directly.
•Program (local), which cannot be directly accessed, but can be
copied to a controller scope tag.
•Data type, which defines the organization of the data.
See CIP data types for more information.
In the Logix Designer application, version 21.00.00 and later, and in
RSLogix 5000 software, version 18.00.00 and later, external access to
Atomic data type sizes
Logix 5000 data

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
1756-PM004.
For more information about tags and data types, see the Logix 5000
Controllers Design Considerations Reference Manual, publication
1756-RM094.
See also
CIP data types on page 13
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 on page 38
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

Chapter 1
CIP services
16 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
These values are based on the CIP Data Type Reporting Values that are
defined in Volume 1, Appendix C of the CIP Networks Library, but are
extended to 16-bits.
The Request Path in a CIP explicit message contains addressing information
indicating which internal resource in the target node directs the service. This
addressing information is organized by using Logical Segments, Symbolic
Segments, or both.
For more detailed information about segments, see the CIP Networks
Library, Volume 1, Appendix C.
The following is a summary of the Logical Segment types defined by CIP
that are supported by the Logix 5000 controller.
See also
CIP services overview on page 13
These tables explain the Logical Segments. Not all segment types defined by
CIP are supported by Logix 5000 controllers.
Segment Type Value Byte Order Representation of Element ID Value (low byte first)
0 1 … n n+1
8-bit Element ID 0x28 Value N/A N/A N/A N/A
16-bit Element ID 0x29 00 Low High N/A N/A
32-bit Element ID 0x2A 00 Lowest Low High Highest
Segment Type Value Byte Order Representation of Class ID Value (low byte first)
0 1 … n n+1
8-bit Class ID 0x20 Value N/A N/A N/A N/A
16-bit Class ID 0x21 00 Low High N/A N/A
Segment Type Value Byte Order Representation of Instance ID Value (low byte first)
0 1 … n n+1
8-bit Instance ID 0x24 Value N/A N/A N/A N/A
16-bit Instance ID 0x25 00 Low High N/A N/A
Analysis
Segment Encoding
Logical Segments

CIP services
Chapter 1
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 17
Segment Type Value Byte Order Representation of Attribute ID Value (low byte first)
0 1 … n n+1
8-bit Attribute ID 0x30 Value N/A N/A N/A N/A
16-bit Attribute ID 0x31 00 Low High N/A N/A
See also
CIP services on page 13
Segment Encoding on page 16
CIP defines a way to reference items by their symbolic name. The segment
used is the ANSI Extended Symbol Segment defined in the CIP Networks
Library, Volume 1, Appendix C.
The Read/Write tags services can use these segments in the request path to
indicate which target tag to operate on. When addressing an arrayed tag, the
Logical Segment for Element ID is also used with the Symbolic Segment.
Segment Type Value Byte Order Representation (low byte first)
0 1 … N N+1
ANSI Extended Symbolic 0x91 Length 1st char … Nth Char (1)
See also
Segment Encoding on page 16
All CIP services follow the Message Router Request/Response format
defined in the CIP Networks Library, Volume 1, Chapter 2. For complete
descriptions,see the CIP Networks Library.All requests take this form.
Message Request Field Description
Request Service Indicates to the object referenced in the request path to perform a task. The CIP or the
device manufacturer define these tasks. Most of the services covered in this manual are
defined by the Rockwell Automation vendor-specific objects, and are not found inthe CIP
Networks Library.
Request Path Size A byte value that indicates the number of 16-bit words in the Request Path.
Request Path A variable sized field that consists of one or more segments. The path references the item
that services operate on in the controller. The path contains Logical or Symbolic segments
or both.
Request Data The service-specific data that is delivered to the object referenced in the Request Path. This
field only appears in the message frame if a service has service-specific data.
This same form is used for ControlNet and EtherNet/IP communication
CIP-based networks. Requests received through the serial port use another
protocol.
Symbolic Segments
CIP Service Request/Response
Format

Chapter 1
CIP services
18 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Use the CIP service format for CIP-explicit messages and to deliver
connected or unconnected messages to the controller. The mechanisms for
doing this are CIP-network specific. For example, for EtherNet/IP access, see
the CIP Networks Library, Volume 1 unconnected, Chapter 3 and the
EtherNet/IP Adaptation of CIP, Volume 2.
For more information about using the EtherNet/IP network to communicate
with the controller, see
http://www.rockwellautomation.com/rockwellautomation/solutions-services/
oem/design-develop-deliver/information-enabled-solutions.page. We
recommend using connected messaging whenever possible. Be aware that the
information presented here does not replace the need to be properly
authorized by ODVA, Inc. to use the Ethernet/IP protocol.
The examples used throughout the manual show only the explicit message
protocol elements and not the network-specific details. The exception to this
is the information in CIP Over the Controller Serial Port, which shows more
details of unconnected versus connected explicit messages, andofthe
PCCC and DF1 layers. All responses take the general form as shown in the
table.
Message Response
Field
Description
Reply Service The request service with the MSB set to 1.
00 Reserved.
General Status An 8-bit value indicating success or error status. The CIP Networks Library, Volume 1,
Appendix B has a list of the general status codes. The object class specified in the request
path defines any extended status codes for each service defined for that class.
Extended Status Size An 8-bit value that indicates how many 16-bit values follow in the additional status field.
For status=0 (success) this is 0.
Extended Status The array of 16-bit values that describe the general status code. Only present when the size
field is > 0.
Reply Data The data returned by the service request. This field only appears in the message frame if a
service has service-specific data.
See also
CIP Over the Controller Serial Port on page 75
PCCC Commands on page 81
These sections describe the inherent mode of communication and addressing
of the Logix 5000 controller. The following vendor-specific services operate
on tags in the controller using symbolic addressing:
•Read Tag Service (0x4c)
•Read Tag Fragmented Service (0x52)
•Write Tag Service (0x4d)
•Write Tag Fragmented Service (0x53)
Services Supported by
Logix 5000 Controllers

CIP services
Chapter 1
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019 19
•Read Modify Write Tag Service (0x4e)
The first four services preceding can be used with two addressing methods:
•Symbolic Segment Addressing
•Symbol Instance Addressing (available in version 21 and later.)
This table describes the addressing methods.
Addressing Method How it Works When to Use
Symbolic Segment
•
Uses the name of the tag in an ASCII format using ANSI
Extended Symbolic Segments
•Allows direct access to the tags as displayed in the
Logix Designer application Data Monitor
•The number of characters in the name affects:
•Packet size
•The number of services that can fit in the
Multiple Service Packet service
•The parsing time of the incoming message in
the controller
•
For best performance in applications that access small to
moderate amounts of data.
•For improving performance by organizing the data into
user-defined structures and accessing those structures.
Symbol Instance
•Uses the instance ID of the symbol class for the tag you
want to access.
•The client application that accesses the controller
must:
•Retrieve the symbol instance information
from the controller to associate the name
of the tag with its instance ID
•Use the instance ID to access the tag.
For best performance in applications that access a large
number of tags.
Also use the Multiple Service Packet Service (0x0a) to combine multiple
requests in one message frame. This improves performance when accessing
many tags by minimizing the time to transmit and process multiple packets.
The number of requests that are included is limited by the size of each
request. This depends on the content of the request. For example, the number
of characters in the tag names impacts the number of requests combined by
the Multiple Service Packet Service. For further information, see Multiple
Service Packet Service.
These services have more descriptive names than earlier versions of this
publication.
Service Service name in earlier versions of this manual, Service name in Logix Designer
Read Tag Service CIP Read Data CIP Data Table Read
Read Tag Fragmented Service Read Data Fragmented Format N/A
Write Tag Service CIP Write Data CIP Data Table Write
Write Tag Fragmented Service Write Data Fragmented Format N/A

Chapter 1
CIP services
20 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Service Service name in earlier versions of this manual, Service name in Logix Designer
Multiple Service Packet Service Multiple Service Packet Service Multi-Request Service
For further information on services, refer to the services topics in this
chapter.
For examples showing more complex addressing using both types of
addressing, see CIP Addressing Examples.
For further information on the Request Data and Reply Data, refer to the
examples in this chapter.
See also
Multiple Service Packet Service on page 35
CIP Addressing Examples on page 63
Read Tag Service on page 20
Read Tag Fragmented Service on page 22
Write Tag Service on page 27
The Read Tag Service reads the data associated with the tag specified in the
path.
•Any data that fits into the reply packet is returned, even if it does not
all fit.
•If all the data does not fit into the packet, the error 0x06 is returned
along with the data.
•When reading a two or three dimensional array of data, all dimensions
must be specified.
•When reading a BOOL tag, the values returned for 0 and 1 are 0 and
0xFF, respectively.
See also
Services Supported by Logix 5000 Controllers on page 18
Example Using Symbolic Segment Addressing on page 20
Example Using Symbol Instance Addressing on page 21
Read a single tag named rate using Symbolic Segment Addressing. The tag
has a data type of DINT and a value of 534. The value used for Instance ID
was determined using methods described in CIP Services and User-created
Tags.
Read Tag Service
Example Using Symbolic
Segment Addressing