Rockwell Automation 1756 ControlLogix, 1756 GuardLogix, 1769 CompactLogix, 1769 Compact GuardLogix, 1789 SoftLogix Programming 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

Original Instructions

Logix 5000 Controllers Data Access

personal injury or death, property damage, or economic loss.

Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.

IMPORTANT

SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present.

temperatures.

for Personal Protective Equipment (PPE).

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.

No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual.

Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited.

Throughout this manual, when necessary, we use notes to make you aware of safety considerations.

WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to

ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss.

Identifies information that is critical for successful application and understanding of the product.

Labels may also be on or inside the equipment to provide specific precautions.

BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous

ARC FLASH HAZARD:

will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL Regulatory requirements for safe work practices and

Labels may be on or inside the equipment, for example, a motor control center, to alert people to potential Arc Flash. Arc Flash

2 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Change

Topic

Updated branding.

Throughout

Summary of 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

This table identifies changes that apply to all information about a subject in the manual and the reason for the change. For example, the addition of new supported hardware, a software design change, or additional reference material would result in changes to all of the topics that deal with that subject.

Updated Legal notices. Legal notices on page 10

New or enhanced features

None in this version.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 3

Summary of Changes CIP services

Preface

Studio 5000 environment .......................................................................... 9

Additional resources ................................................................................... 9

Legal notices ...............................................................................................10

Chapter 1

CIP Services Overview ............................................................................... 11

CIP Data Types ..................................................................................... 11

Atomic data type sizes ................................................................... 12

Logix 5000 data .................................................................................... 12

Tag type service parameter ................................................................. 13

Tag type service parameter values used with Logix controllers . 13

Analysis ................................................................................................. 13

Segment Encoding ............................................................................... 13

Logical Segments ........................................................................... 14

Symbolic Segments ........................................................................ 14

CIP Service Request/Response Format .............................................. 15

Services Supported by Logix 5000 Controllers ........................................ 16

Read Tag Service .................................................................................. 18

Example Using Symbolic Segment Addressing .......................... 18

Example Using Symbol Instance Addressing .............................. 18

Read Tag Service Error Codes ....................................................... 19

Read Tag Fragmented Service ............................................................. 19

Example Using Symbolic Segment Addressing ......................... 20

Example Using Symbol Instance Addressing .............................. 21

Read Tag Fragmented Service Error Codes .................................23

Write Tag Service ................................................................................ 24

Example Using Symbolic Segment Addressing ......................... 24

Example Using Symbol Instance Addressing ............................. 24

Write Tag Service Error Codes .................................................... 25

Write Tag Fragmented Service .......................................................... 25

Example Using Symbolic Segment Addressing ......................... 26

Example Using Symbol Instance Addressing ............................. 27

Write Tag Fragmented Service Error Codes............................... 29

Read Modify Write Tag Service.......................................................... 30

Service Request Parameters ......................................................... 30

Example ......................................................................................... 30

Read Modify Write Tag Service Error Codes ............................... 31

Multiple Service Packet Service .................................................... 31

Example .......................................................................................... 31

Logix Data Structures ................................................................................32

Work with Data Structures ................................................................. 33

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 5

Table of Contents

CIP Services and CIP Addressing Examples

User-created Tags

Tag type service parameters for structure ......................................... 34

Chapter 2

How tags are organized in the controller ................................................ 37

Symbol object ...................................................................................... 38

Template object ................................................................................... 38

Create and maintain a symbol object list ................................................ 40

Step 1: Find user-created controller scope tags in a Logix 5000

controller ..................................................................................................... 41

Retrieve all symbol object instances ................................................... 41

Example of retrieving the first group of tags .................................... 42

Analysis ................................................................................................ 42

Continue the retrieval process ...................................................... 43

Step 2: Isolate user-created tags from system tags/identifying

structured tags ............................................................................................44

Symbol Type Attribute .........................................................................44

Eliminate tags by applying rules.................................................. 46

Step 3: Determine the structure makeup for a specific structure .......... 47

Example of reading template attributes ............................................ 47

Analysis ................................................................................................ 48

Structure data format ................................................................... 49

Contents of the member information ......................................... 50

Example of retrieving member information .............................. 50

Example ......................................................................................... 50

More about BOOLS in UDTs ........................................................ 52

Step 4: Determine the data packing of the members of a structure when

accessed as a whole..................................................................................... 53

Example of reading an entire structure ............................................. 53

Step 5: Determine when the tags list and structure information need

refreshing .................................................................................................... 54

How to detect changes ......................................................................... 54

6 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Chapter 3

Atomic Members of Predefined Data Types ............................................ 57

Example 1 (Symbolic Segment Addressing Method)......................... 57

Example 2 (Symbol Instance Addressing Method) .......................... 58

Example 3 (Symbolic Segment Addressing Method) ....................... 58

Example 4 (Symbolic Segment Addressing Method) ........................59

Example 5 (Symbol Instance Addressing Method) ............................59

Example 6 (Symbolic Segment Addressing Method) ....................... 60

Example 7 (Symbolic Segment Addressing Method) ........................ 61

Example 8 (Both Addressing Methods) .............................................. 61

CIP Over the Controller

Serial Port

Index

Table of Contents

Example 9 (Both Addressing Methods) ............................................. 62

Example 10 (Symbolic Segment Addressing Method) with BOOLs 62

Access User-Defined Structures ................................................................ 63

Example 1 ............................................................................................. 64

Example 2............................................................................................. 64

Example 3 ..............................................................................................65

Example 4 ..............................................................................................65

Example 5 ............................................................................................. 66

Example 6 ............................................................................................. 66

Chapter 4

Unconnected Messaging (UCMM) through PCCC ................................ 69

Connected Explicit Messages through PCCC ......................................... 70

Fragmentation Protocol ........................................................................... 72

PCCC Commands ....................................................................................... 73

Supported Subset of PCCC Commands ................................................... 73

Initial Fields of All PCCC Commands ....................................................... 74

PLC-2 Communication Commands .......................................................... 75

Unprotected Read (CMD=01, 41; FNC not present) ........................... 75

Protected Write (CMD=00, 40; FNC not present) ............................. 75

Unprotected Write (CMD=08, 48; FNC not present) ........................ 75

Protected Bit Write (CMD=02, 42; FNC not present) ........................ 76

Unprotected Bit Write (CMD=05, 45; FNC not present) ................... 76

PLC-5 Communication Commands .......................................................... 77

Addressing examples ........................................................................... 77

Read Modify Write N (CMD=0F, 4F; FNC=79) .................................. 78

Typed Read (CMD=0F, 4F; FNC=68) ................................................... 79

Typed Write (CMD=0F, 4F; FNC=67) .................................................. 79

Word Range Read (CMD=0F, 4F; FNC=01) ........................................ 79

Word Range Write (CMD=0F, 4F; FNC=00) ..................................... 80

Bit Write (CMD=0F, 4F; FNC=02) ...................................................... 80

SLC Communication Commands ............................................................. 81

SLC Protected Typed Logical Read with 3 Address Fields (CMD=0F,

4F; FNC=A2) .......................................................................................... 81

SLC Protected Typed Logical Write with 3 Address Fields(CMD=0F,

4F, FNC=AA) ........................................................................................ 82

SLC Protected Typed Logical Read with 2 Address Fields (CMD=0F,

4F; FNC=A1) ......................................................................................... 82

SLC Protected Typed Logical Write with 2 Address Fields (CMD=0F,

4F; FNC=A9) ......................................................................................... 83

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 7

Resource

Description

at http://ab.rockwellautomation.com

and other certification details.

Studio 5000 environment

Additional resources

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.

Industrial Automation Wiring and Grounding Guidelines, publication 1770-4.1

Product Certifications webpage, available

Provides general guidelines for installing a Rockwell Automation industrial system.

Provides declarations of conformity, certificates,

View or download publications at http://www.rockwellautomation.com/literature

. To order paper copies of technical documentation, contact the local Rockwell Automation distributor or sales representative.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 9

Preface

Legal notices

Rockwell Automation publishes legal notices, such as privacy policies, license agreements, trademark disclosures, and other terms and conditions on

the Legal Notices

page of the Rockwell Automation website.

End User License Agreement (EULA)

You can view the Rockwell Automation End User License Agreement (EULA) by opening the license.rtf file located in your product's install folder on your hard drive.

The default location of this file is:

C:\Program Files (x86)\Common Files\Rockwell\license.rtf.

Open Source Software Licenses

The software included in this product contains copyrighted software that is licensed under one or more open source licenses.

You can view a full list of all open source software used in this product and their corresponding licenses by opening the oss_license.txt file located your product's OPENSOURCE folder on your hard drive. This file is divided into these sections:

• Components Includes the name of the open source component, its version number, and the type of license.

• Copyright Text Includes the name of the open source component, its version number, and the copyright declaration.

• Licenses Includes the name of the license, the list of open source components citing the license, and the terms of the license.

The default location of this file is:

C:\Program Files (x86)\Common Files\Rockwell\Help\<product name>\Release Notes\OPENSOURCE\oss_licenses.txt.

You may obtain Corresponding Source code for open source packages included in this product from their respective project web site(s). Alternatively, you may obtain complete Corresponding Source code by contacting Rockwell Automation via the Contact form on the Rockwell Automation website:

http://www.rockwellautomation.com/global/aboutus/contact/contact.page. Please include "Open Source" as part of the request

text.

10 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

CIP Services Overview

CIP Data Types

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 11

Tag type service parameter on page 13

Analysis on page 13

Segment Encoding on page 13

CIP Service Request/Response Format on page 15

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 userdefined structures.

• Array. A sequence of elements, each of which is the same data type.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 11

• 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

Chapter 1 CIP services

To store a

Use this data type

8-bit integer

SINT

16-bit integer

INT

32-bit integer

DINT

32-bit float

REAL

64-bit integer

LINT

Atomic data type sizes

Logix 5000 data

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 11

Atomic data type sizes on page 12

Logix 5000 data on page 12

Use the atomic data type sizes table for the data type value to use to store a bit.

Bit BOOL Bit array DWORD (32-bit boolean array)

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 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.

12 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

For more information about tags and data types, see the Logix 5000

Controllers Design Considerations Reference Manual, publication 1756RM094.

Data Type

Tag Type Value

Size of Transmitted Data

INT

0x00C3

2 bytes

DINT

0x00C4

4 bytes

REAL

0x00CA

4 bytes

bytes = Multi-byte data values are transmitted low-byte first

Tag type service parameter

Analysis

Segment Encoding

Chapter 1 CIP services

See also

CIP data types on page 11

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 34

values used with Logix controllers

Use this table for date types, tag type values, and size of transmitted data for Logix controllers.

BOOL 0x0nc1

The BOOL value includes an additional field (n) for specifying the bit position within the SINT (n = 0-7).

SINT 0x00C2 1 byte

DWORD 0x00D3 4 bytes LINT 0x00C5 8 bytes

1 byte

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.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 13

For more detailed information about segments, see the CIP Networks Library, Volume 1, Appendix C.

Chapter 1 CIP services

Segment Type

Value

Byte Order Representation of Element ID Value (low byte first)

0 1 … n n+1

16-bit Element ID

0x29

Low

High

N/A

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

16-bit Class ID

0x21

Low

High

N/A

Segment Type

Value

Byte Order Representation of Instance ID Value (low byte first)

0 1 … n n+1

16-bit Instance ID

0x25

Low

High

N/A

Segment Type

Value Byte Order Representation of Attribute ID Value (low byte first)

0 1 … n n+1

16-bit Attribute ID

0x31

Low

High

N/A

Logical Segments

Symbolic Segments

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 11

These tables explain the Logical Segments. Not all segment types defined by

CIP are supported by Logix 5000 controllers.

8-bit Element ID 0x28 Value N/A N/A N/A N/A

32-bit Element ID 0x2A 00 Lowest Low High Highest

8-bit Instance ID 0x24 Value N/A N/A N/A N/A

8-bit Attribute ID 0x30 Value N/A N/A N/A N/A

See also

CIP services on page 11

Segment Encoding on page 13

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.

14 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Segment Type

Value

Byte Order Representation (low byte first)

0 1 … N N+1

Symbolic

Message Request

Description

Request Service

Indicates to the object referenced in the request path to perform a task. The CIP

are not found in the CIP Networks Library.

Symbolic segments or both.

service-specific data.

CIP Service

Chapter 1 CIP services

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.

Request/Response Format

ANSI Extended

0x91 Length 1st char … Nth Char (1)

See also

Segment Encoding on page 13

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.

Field

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

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

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

This same form is used for ControlNet and EtherNet/IP communication CIPbased networks. Requests received through the serial port use another protocol.

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/solutionsservices/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

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 15

Chapter 1 CIP services

Message Response

Description

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.

when the size field is > 0.

frame if a service has service-specific data.

Addressing Method

How it Works

When to Use

Symbolic Segment

Uses the name of the tag in an ASCII format using

the controller

For best performance in applications that access

the information in CIP Over the Controller Serial Port, which shows more details of unconnected versus connected explicit messages, and of the PCCC and DF1 layers. All responses take the general form as shown in the table.

Field

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 The array of 16-bit values that describe the general status code. Only present

Reply Data The data returned by the service request. This field only appears in the message

See also

Services Supported by Logix 5000 Controllers

CIP Over the Controller Serial Port on page 69

PCCC Commands on page 73

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)

• 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.

•

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

•

small to moderate amounts of data.

• For improving performance by organizing the data into user-defined structures and accessing those structures.

16 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Addressing Method

How it Works

When to Use

Service

Service name in earlier versions of this manual,

Service name in Logix Designer

Read Tag Service

CIP Read Data

CIP Data Table Read

Multiple Service Packet Service

Multi-Request Service

Chapter 1 CIP services

Symbol Instance • Uses the instance ID of the symbol class for the

tag you want to access.

• The client application that accesses the controller

• Retrieve the symbol instance information from

•

must

the controller to associate the name of the tag with its instance ID Use the instance ID to access the tag.

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.

For best performance in applications that access a large number of tags.

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

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 31

CIP Addressing Examples on page 57

Read Tag Service on page 18

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 17

Read Tag Fragmented Service on page 19

Write Tag Service on page 24

Chapter 1 CIP services

1st Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

Request Data

01 00

Number of elements to read (1)

1st Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

Reply Data

C4 00

DINT Tag Type Value

Read Tag Service

Example Using Symbolic

Example Using Symbol

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 16

Example Using Symbolic Segment Addressing on page 18

Example Using Symbol Instance Addressing on page 18

Segment Addressing

Request Service 4C Read Tag Service (Request)

Request Path 91 0A 54 6F 74 61 6C 43 6F 75 6E 74 ANSI Ext. Symbolic Segment for

Reply Service CC Read Tag Service (Reply)

General Status 00 Success Extended Status Size 00 No extended status

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.

TotalCount

16 02 00 00 0000216 = 534 decimal

See also

Instance Addressing

18 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

CIP Services and User-created Tags on page 37

Read a single tag named rate using Symbol Instance Addressing. The tag has a data type of DINT and a value of 534.

1st Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Path Size

Request Path is 3 words (6 bytes) long

1st Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

Extended Status Size

No extended status

Reply Data C4 00

DINT Tag Type Value

Error Code (Hex)

Extended Error (Hex)

Description of Error

0x05

0x0000

Request Path destination unknown: Probably instance number is not present.

0x06

N/A

Insufficient Packet Space: Not enough room in the response buffer for all the data.

0x13

N/A

Insufficient Request Data: Data too short for expected parameters.

Read Tag Service

Read Tag

Request Service 4C Read Tag Service (Request)

Chapter 1 CIP services

Request Path 20 6B

25 00 8F F6

Request Data 01 00 Number of elements to read (1)

Logical Segment for Symbol Class ID Logical Segment for Instance ID of the tag

Reply Service CC Read Tag Service (Reply)

General Status 00 Success

16 02 00 00 0000216 = 534 decimal

See also

Read Tag Service on page 18

Services Supported by Logix 5000 Controllers on page 16

Both Symbolic Segment Addressing and Symbol Instance Addressing may return these errors.

Error Codes

rate

0x04 0x0000 A syntax error was detected decoding the Request Path.

0x26 N/A The Request Path Size received was shorter or longer than expected. 0xFF 0x2105 General Error: Access beyond end of the object.

See also

Read Tag Service on page 18

The Read Tag Fragmented Service enables client applications to read a tag with data that does not fit into a single packet (approximately 500 bytes). The

Fragmented Service

client must issue a series of requests to the controller to retrieve the data using this service. The client must change the Offset field value with each

request by the number of bytes transferred in the response to the previous request.

The Byte Offset field is expressed in number of bytes regardless of the data type being read. In the example following, the data type being read is SINT,

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 19

Chapter 1 CIP services

1st Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

Request Path

91 0A 54 6F 74 61 6C 43 6F 75 6E 74

ANSI Ext. Symbolic Segment for

TotalCount

00 00 00 00

Start at this byte offset (0) and return as much as will fit

1st Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

Extended Status Size

No extended status

2nd Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

Request Path

91 0A 54 6F 74 61 6C 43 6F 75 6E 74

ANSI Ext. Symbolic Segment for

TotalCount

2nd Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

General Status

Reply Data Too Large

Extended Status Size

No extended status

Example Using Symbolic

Segment Addressing

Request Service 52 Read Tag Fragmented Service (Request)

Request Data D6 06 Number of elements to read (1750)

which happens to be a byte. The elements and offset are in the same units, which is not the case for other data types.

See also

CIP services on page 11

Services Supported by Logix 5000 Controllers on page 16

Reading the tag TotalCount that has 1750 SINTs consists of these four service requests with service data, as shown in the tables.

Reply Service D2 Read Tag Fragmented Service (Reply)

General Status 06 Reply Data Too Large

Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Elements 0 through 489

Request Service 52 Read Tag Fragmented Service (Request)

Request Data D6 06 Number of elements to read (1750)

EA 01 00 00 Start at this byte offset (490) and return as much as will fit

Reply Service D2 Read Tag Fragmented Service (Reply) Reserved 00

Reply Data C2 00 SINT Tag Type Value

20 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

nn nn nn…nn Data for Elements 490 through 979

3rd Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

Request Path

91 0A 54 6F 74 61 6C 43 6F 75 6E 74

ANSI Ext. Symbolic Segment for

TotalCount

3rd Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

4th Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

Request Path

91 0A 54 6F 74 61 6C 43 6F 75 6E 74

ANSI Ext. Symbolic Segment for

TotalCount

4th Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

General Status

Success

1st Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Example Using Symbol

Request Service 52 Read Tag Fragmented Service (Request)

Request Data D6 06 Number of elements to read (1750)

D4 03 00 00 Start at this offset (980) and return as much as will fit

Chapter 1 CIP services

Reply Service D2 Read Tag Fragmented Service (Reply) Reserved 00

General Status 06 Reply Data Too Large Extended Status Size 00 No extended status Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Elements 980 through 1469

Request Service 52 Read Tag Fragmented Service (Request)

Request Data D6 06 Number of elements to read (1750)

BE 05 00 00 Start at this offset (1470) and return as much as will fit

Reply Service D2 Read Tag Fragmented Service (Reply) Reserved 00

Extended Status Size 00 No extended status Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Elements 1470 through1749

See also

Read Tag Fragmented Service Error Codes on page 23

Instance Addressing

Request Service 52 Read Tag Fragmented Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 21

Reading the tag TotalCount that has 1750 SINTs using Symbol Instance Addressing would consist of these four service requests with service data, as shown in the tables. The value used for Instance ID was determined using methods described in CIP Services and User-created Tags.

Chapter 1 CIP services

1st Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Data Offset

00 00 00 00

Start at this element (0) and return as much will fit

1st Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

General Status

Reply Data Too Large

Extended Status Size

No extended status

nn nn nn…nn

Data for Elements 0 thorough 489

2nd Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Data Offset

EA 01 00 00

Start at this element (490) and return as much will fit

2nd Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

00 General Status

Reply Data Too Large

3rd Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Service

Read Tag Fragmented Service (Request)

Request Path Size

Request Path is 3 words (6 bytes) long

3rd Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

Request Path 20 6B

25 00 1A E0

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

Request Data D6 06 Number of elements to read (1750)

Reply Service D2 Read Tag Fragmented Service (Reply)

Reply Data C2 00 SINT Tag Type Value

Request Service 52 Read Tag Fragmented Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

Request Path 20 6B

25 00 1A E0

Request Data D6 06 Number of elements to read (1750)

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

TotalCount

)

Reply Service D2 Read Tag Fragmented Service (Reply)

Extended Status Size 00 No extended status Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Element 490 through 979

Request Path 20 6B

25 00 1A E0

Request Data D6 06 Number of elements to read (1750) Data Offset D4 03 00 00 Start at this element (980) and return as much will fit

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

TotalCount

Reply Service D2 Read Tag Fragmented Service (Reply)

22 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

General Status

Reply Data Too Large

Extended Status Size

No extended status

4th Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Data Offset

BE 05 00 00

Start at this element (1470) and return as much will fit

4th Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

00 General Status

Reply Data Too Large

Error Code (Hex)

Extended Error (Hex)

Description of Error

0x05

0x0000

Request Path destination unknown: probably instance number is not present.

0x06

N/A

Insufficient Packet Space: Not enough room in the response buffer for all the data.

0x13

N/A

Insufficient Request Data: Data too short for expected parameters.

0x26

N/A

The Request Path Size received was shorter or longer than expected.

Read Tag Fragmented

Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Elements 980 through 1469

Chapter 1 CIP services

Request Service 52 Read Tag Fragmented Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

Request Path 20 6B

25 00 1A E0

Request Data D6 06 Number of elements to read (1750)

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

Reply Service D2 Read Tag Fragmented Service (Reply)

TotalCount

Extended Status Size 00 No extended status Reply Data C2 00 SINT Tag Type Value

nn nn nn…nn Data for Elements 1490 through 1749

Each response, except the last one, shows the General Status of 06, Reply Data Too Large, to indicate that more data is present than is in this particular frame.

The last response shows the General Status of 0 indicating that the data read did not exceed the message size limit. This means that the entire sequence of bytes has been read.

See also

CIP Services and User-created Tags on page 37

The Symbolic Segment Addressing and Symbol Instance Addressing may return these errors.

Service Error Codes

0x04 0x0000 A syntax error was detected decoding the Request Path.

0xFF 0x2105 General Error: Number of Elements or Byte Offset is beyond the end of the requested tag.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 23

Chapter 1 CIP services

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

0E 00 00 00

Data 0000000E=14 decimal

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

General Status

Success

Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Write Tag Service

Example Using Symbolic

Segment Addressing

See also

CIP services on page 11

Services Supported by Logix 5000 Controllers on page 16

The Write Tag Service writes the data associated with the tag specified in the path. The tag type must match for the write to occur. The controller validates

the tag type matches before executing the service.

• When writing a two or three dimensional array of data, all dimensions must be specified.

• When writing to a BOOL tag, any non-zero value is interpreted as 1.

See also

Write Tag Service Error Codes on page 25

Write the value of 14 to a DINT tag named CartonSize using Symbolic Segment Addressing.

Request Service 4D Write Tag Service (Request)

Request Path 91 0A 43 61 72 74 6F 6E 53 69 7A 65 ANSI Ext. Symbolic Segment for Request Data C4 00 DINT Tag Type Value

01 00 Number of elements to write (1)

Reply Service CD Write Tag Service (Reply)

Extended Status Size 00 No extended status

See also

Write Tag Service on page 24

Example Using Symbol Instance Addressing

Write the value of 14 to a DINT tag named CartonSize using Symbolic Instance Addressing. The value used for Instance ID was determined using methods described in CIP Services and User-created Tags.

CartonSize

Request Service 4D Write Tag Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

24 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

Extended Status Size

No extended status

Error Code (Hex)

Extended Error (Hex)

Description of Error

0x10

0x2101

Device state conflict: keyswitch position: The requestor is changing force 0xFF

0x2107

General Error: Tag type used n request does not match the target tag’s data type.

Write Tag Service

Write Tag

Chapter 1 CIP services

Error Codes

Request Path 20 6B

25 00 36 71

Request Data C4 00 DINT Tag Type Value

01 00 Number of elements to write (1) 0E 00 00 00 Data 0000000E=14 decimal

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

Reply Service CD Write Tag Service (Reply)

General Status 00 Success

See also

CIP Services and User-created Tags on page 37

The Symbolic Segment Addressing and Symbol Instance Addressing may returns these error codes.

CartonSize

0x04 0x0000 A syntax error was detected decoding the Request Path. 0x05 0x0000 Request Path destination unknown: Probably instance number is not present.

0x10 0x2802 Device state conflict: Safety Status: The controller is in a state in which Safety

0x13 N/A Insufficient Request Data: Data too short for expected parameters. 0x26 N/A The Request Path Size received was shorter or longer than expected. 0xFF 0x2105 General Error: Number of Elements extends beyond the end of the requested tag.

Fragmented Service

information in HARD RUN mode.

Memory cannot be modified.

See also

Write Tag Service on page 24

The Write Tag Fragmented Service enables client applications to write to a tag in the controller whose data will not fit into a single packet (approximately 500 bytes). The client must issue a series of requests to the controller to write all data using this service.

The Request Service, Request Path Size, Request Path, and Number of Elements fields remain the same for each request. The client must change the byte offset field value with each request by the number of bytes it transferred in the previous request.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 25

Chapter 1 CIP services

1st Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path

91 0A 54 6F 74 61 6C 43 6F 75 6E 74

ANSI Ext. Symbolic Segment for

TotalCount

00 00 00 00

Start at this offset.

nn, nn, …nn

Element Data for Elements 0 through 473

1st Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

2nd Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

2nd Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Example Using Symbolic

Segment Addressing

Request Service 53 Read Tag Fragmented Service (Request) Request Path Size 06 Request Path is 6 words (12 bytes) long

The Byte Offset field is expressed in number of bytes regardless of the data type being read. In the examples that follow, the data type being read is SINT, which happens to be a byte. In this case, the elements and offset are in the same units, which is not the case for other data types.

See also

Example Using Symbolic Segment Addressing on page 26

Example Using Symbol Instance Addressing on page 27

Writing 1750 SINTs to the tag TotalCount using Symbolic Segment Addressing would consist of the following four service requests with service data as shown in the tables that follow. The value used for Instance ID was determined using methods described in CIP Services and User-created Tags.

Request Data C2 00 SINT Tag Type Value

D6 06 Total number of elements to write (1750)

Reply Service D3 Write Tag Fragmented Service (Reply) Reserved 00

General Status 00 Success Extended Status Size 00 No extended status

Request Service 53 Write Tag Fragmented Service (Request) Request Path Size 06 Request Path is 6 words (12 bytes) long

Request Path 91 0A 54 6F 74 61 6C 43 6F 75 6E 74 ANSI Ext. Symbolic Segment for Request Data C2 00 SINT Tag Type Value

D6 06 Total number of elements to write (1750) DA 01 00 00 Start at this offset.

nn, nn, …nn Element Data for Elements 474 through 947

TotalCount

Reply Service D3 Write Tag Fragmented Service (Reply) Reserved 00

General Status 00 Success

26 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

2nd Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

3rd Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 6 words (12 bytes) long

B4 03 00 00

Start at this offset

3rd Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

4th Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Data

C2 00

SINT Tag Type Value

8E 05 00 00

Start at this Offset

nn, nn, …nn

Element Data for Elements 1422 through 1749

4th Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

00 General Status

Success

Extended Status Size

No extended status

Example Using Symbol

Extended Status Size 00 No extended status

Chapter 1 CIP services

Request Service 53 Write Tag Fragmented Service (Request)

Request Path 91 0A 54 6F 74 61 6C 43 6F 75 6E 74 ANSI Ext. Symbolic Segment for Request Data C2 00 SINT Tag Type Value

D6 06 Total number of elements to write (1750)

nn, nn, …nn Element Data for Elements 948 through 1421

TotalCount

Reply Service D3 Write Tag Fragmented Service (Reply)

General Status 00 Success Extended Status Size 00 No extended status

Request Service 53 Write Tag Fragmented Service (Request) Request Path Size 06 Request Path is 6 words (12 bytes) long

Request Path 91 0A 54 6F 74 61 6C 43 6F 75 6E 74 ANSI Ext. Symbolic Segment for

D6 06 Total number of elements to write (1750)

TotalCount

Reply Service D3 Write Tag Fragmented Service (Reply)

Instance Addressing

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 27

See also

CIP Services and User-created Tags on page 37

Writing 1750 SINTs to the tag TotalCount using Symbol Instance Addressing would consist of the following four service requests with service data as shown in the tables.

Chapter 1 CIP services

1st Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Path Size

Request Path is 3 words (6 bytes) long

D6 06

Number of elements to write (1750)

00 00 00 00

Start at this Offset

nn,nn,...nn

Element Data for Elements 0 through 473

1st Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reply Service

Write Tag Fragmented Service (Reply)

Reserved

00 General Status

Success

Extended Status Size

No extended status

2nd Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Service

Write Tag Fragmented Service (Request)

Request Path Size

Request Path is 3 words (6 bytes) long

nn,nn,...nn

Element Data (474 through 947)

2nd Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

General Status

Success

Extended Status Size

No extended status

3rd Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Service

Write Tag Fragmented Service (Request)

Request Path Size

Request Path is 3 words (6 bytes) long

nn,nn,...nn

Element Data (948 through 1421)

Request Service 53 Write Tag Fragmented Service (Request)

Request Path 20 6B

25 00 1A E0

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

Request Data C2 00 SINT Tag Type Value

Request Path 20 6B

25 00 1A E0

Request Data C2 00 Tag Data Type

D6 06 Number of elements to write (1750) EC 01 00 00 Start at this Offser

Logical Segments for Symbol Class ID Logical Segment for Instance ID for the tag

TotalCount

Reply Service D3 Write Tag Fragmented Service (Reply) Reserved 00

Request Path 20 6B

25 00 1A E0

Request Data C2 00 Tag Data Type

D6 06 Number of elements to write (1750) B4 03 00 00 Start at this Offset

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

TotalCount

28 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

3rd Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

General Status

Success

Extended Status Size

No extended status

4th Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

nn,nn,...nn

Element Data (1422 through 1749)

4th Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

General Status

Success

Extended Status Size

No extended status

Error Code (Hex)

Extended Error (Hex)

Description of Error

0x13

N/A

Insufficient Request Data: Data is too small for expected parameters.

0x26

N/A

The Request Path Size received was shorter or longer than expected.

0xFF

0x2105

General Error: Offset plus Number of Elements extends beyond the end of the requested tag.

0xFF

0x2107

General Error: Data type used in request does not match the data type of the target tag.

Write Tag Fragmented

Reply Service D3 Write Tag Fragmented Service (Reply)

Chapter 1 CIP services

Request Service 53 Write Tag Fragmented Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long Request Path 20 6B

25 00 1A E0

Request Data C2 00 Tag Data Type

D6 06 Number of elements to write (1750) 8E 05 00 00 Start at this Offset

Logical Segment for Symbol Class ID Logical Segment for Instance ID for the tag

TotalCount

Reply Service D3 Write Tag Fragmented Service (Reply) Reserved 00

The response to each request shows a General Status value of 00, Success status indication, to indicate that the write operation was successful. No other Reply Data is returned for this service.

See also

Write Tag Fragmented Service on page 25

Symbolic Segment Addressing and Symbol Instance Addressing return these error codes.

Service Error Codes

0x04 0x0000 A syntax error was detected decoding the Request Path. 0x05 0x0000 Request Path destination unknown: instance number is not present.

0x10 0x2101 Device state conflict: keyswitch position: The requestor is changing force information in HARD RUN

mode.

0x10 0x2802 Device state conflict: Safety Status: Unable to modify Safety Memory in the current controller state.

0xFF 0x2104 General Error: Offset is beyond end of the requested tag.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 29

Chapter 1 CIP services

Name

Description of Reply Data

Semantics of Values

OR masks

Array of OR modify masks

1 mask sets bit to 1

AND masks

Array of AND modify masks

0 mask resets bit to 0

Message Request Field

Bytes (in hex)

Description

Request Path Size

Request Path is 7 words (14 bytes) long

Message Reply Field

Bytes (in hex)

Description

Read Modify Write

Service Request Example

Tag Service

Parameters

See also

Write Tag Fragmented Service on page 25

The Read Modify Write Tag Service modifies Tag data with individual bit resolution. ControlLogix controllers read the Tag data, applies the logical or modification masks or both, and writes the data the Tag. Also use the Read Modify Write Tag Service to modify a single bit in a Tag without disturbing

other data.

See also

PCCC Commands on page 73

These are the Service Request Parameters.

Size of masks Size in bytes of modify masks Only 1,2,4,8,12 accepted

The size of masks must be the same or smaller than the size of the data type being accessed. For complete data integrity, the size of the mask should match the size of the data type. For example, to avoid the possibility of a mix of old and new data when modifying dynamic data, the size of the mask must match the size of the data type.

See also

CIP services on page 11

Read Modify Write Tag Service on page 30

Set bit 2 and reset bit 5 of the DINT named ControlWord.

Request Service 4E Read Modify Write Tag Service (Request)

Request Path 91 0B 43 6F 6E 7H 72 6F 6C 57 6F 72 64 00 ANSI Ext. Symbolic Segment for ControlWord Request Data 04 00 Size of Masks (shall be 4)

04 00 00 00 Array of OR modify masks DF FF FF FF Array of AND modify masks

Reply Service CE Read Modify Write Tag Service (Reply) Reserved 00

30 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

General Status

Success

Error Code

Extended Error

Description of Error

0x04

0x0000

A syntax error was detected decoding the Request Path.

0x05

0x0000

Request Path destination unknown: Probably instance number is not present.

force information in HARD RUN mode.

Memory cannot be modified.

0x26

N/A

The Request Path Size received was shorter or longer than expected.

Message Request Field

Bytes (in hex)

Description

Request Path

20 02 24 01

Logical Segment: CLass 0x02, Instance 01 (Message Router)

12 00

Read Modify Write Tag

Multiple Service Example

Extended Status Size 00 No extended status

See also

Read Modify Write Tag Service on page 30

These are the Read Modify Write Tag Service error codes.

Service Error Codes

Chapter 1 CIP services

Packet Service

(Hex)

0x03 N/A Bad parameter, size > 12 or size greater than size of element.

0x10 0x2101 Device state conflict: keyswitch position: The requestor is attempting to change

0x10 0x2802 Device state conflict: Safety Status: The controller is in a state in which Safety

0x13 N/A Insufficient Request Data: Data too short for expected parameters.

(Hex)

See also

Read Modify Write Tag Service on page 30

The Multiple Service Packet Service conducts more than one CIP request in a single CIP explicit-message frame. Use this service to optimize CIP reads and writes by grouping service requests together for faster request processing.

For details on this service, see the CIP Networks Library, Volume 1, Appendix A.

See also

This is an example for Multiple Service Packets.

Request Service 0A Multiple Service Packet Service (Request) Request Path Size 02 Request Path is 2 words (4 bytes) long

Request Data 02 00 Number of Services contained in this request

06 00

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 31

Read Modify Write Tag Service on page 30

CIP services on page 11

Offsets for each Service; from the start of the Request Data

Chapter 1 CIP services

Message Request Field

Bytes (in hex)

Description

04 91 05 70 61 72 74

01 00

Read 1 element

Message Reply Field

Bytes (in hex)

Description

Reserved

00 General Status

Success

Extended Status Size

No extended status

2A 00 00 00

Value: 0x0000002A (42 decimal)

Value: 0x000001DC (476 decimal)

Logix Data Structures

73 00

4C 07 91 0B 43 6F 6E 74 72 6F 6C

57 6F 72 64 00 01 00

First Request: Read Tag Service Tag name: Read 1 element

Second Request: Read Tag Service Tag name:

parts

ControlWord

The Multiple Service Packet Request Path contains the Message Router object (Class 2, Instance 1). This is the destination of the Multiple Service Packet’s Request Path. The Request Data field contains the Number of Services followed by byte offsets to the start of each service, followed by each of the CIP requests, each following the standard Message Router Request format.

Observe this example

Reply Service 8A Multiple Service Packet Service (Reply)

Reply Data 02 00 Number of Service Replies

06 00 10 00

CC 00 00 00 C4 00

Offsets for each Service Reply; from the start of the Reply Data

Read Tag Service Reply, Status: Success DINT Tag Type Value

CC 00 00 00 C4 00 DC 01 00 00

Read Tag Service Reply, Status: Success DINT Tag Type Value

The Multiple Service Packet response follows the same Message Router Response format as all CIP services; therefore, the General Status, Ext Status Size fields are in the same CIP Service Request/Response Format as described in previous examples. The Reply Data field contains the number of service replies followed by the byte offset to the start of each reply, followed by each of the CIP responses. Each of the responses follows the standard Message Router Response format.

See also

Read Modify Write Tag Service on page 30

Multiple Service Packet Service on page 31

A structure is a compound data type that stores a group of possibly different data types that function as a single unit and serve a specific purpose. (For

example, a combination of values.)

32 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Work with Data Structures

Chapter 1 CIP services

• A structure contains one or more members.

• Each member can be an:

• Atomic data type.

• Another structured data type.

• A single dimension array of an atomic or structure data type.

The controller contains these basic types of structures:

• Module-Defined data types - created by adding modules to the I/O tree

• Predefined data types - created by default in the controller (for

example, TON, CTU, and Motion)

• Add-On-Defined data types

• User-Defined data types (UDT) - created by the user

Group most structures into arrays or use them in other structures.

For more information on data types and creating structures

Logix 5000 Controllers Design Considerations Reference Manual, publication 1756RM094.

The Predefined, Add-On-Defined, and Module-Defined types, and Booleans within these structures, are difficult to deal with for various reasons and are beyond the scope of this publication. For alternatives for working with Predefined, Add-On-Defined, and Module-Defined types, and Booleans within these structures see the following topics in this chapter.

See also

Work with Data Structures on page 33

CIP services on page 11

For these guidelines for working with data structures.

• Complete user-defined structure tags, or individual members are accessed. Access to complete structure Tags requires an understanding of the organization and alignment of structure members, which follows rules. The UDT organization are described in the structure Template in CIP Services and User-created Tags. Do not access complete UDT tags that contain nested system structures, such as Module-Defined, Predefined, or Add-On Defined.

• Predefined, Module-Defined, and Add-On-Defined structure tags have a more complex set of rules than user-defined data types (UDT). Do not access complete structure tags of these types, or complete UDTs with nested tags of these types. Instead, access atomic members of these tags that are visible in the Logix Designer application Data Monitor, using one of the methods that follow.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 33

• Create an alias of the atomic member and access the alias instead of

the structure.

Chapter 1 CIP services

Tag type service

• Create an atomic tag or UDT structure tag with an atomic member,

and then have the user program copy the data to and from the tag or atomic member. Access the new tag or atomic member instead.

• In the Logix Designer, version 21 and later, and in RSLogix 5000 software, version 18 and later, external access to controller scope tags is user-selectable. If an External Access tag attribute is set to None, the tag cannot be accessed from outside of the controller. Therefore, structures that contain members whose external access is set to None cannot be accessed as a whole (that is, by reading or writing the entire structure). Similarly, structures that have one or more members whose External Access is set to Read Only cannot be written to as a whole (that is, by reading or writing the entire structure), but the members that are not restricted in access can be accessed by using symbolic segment addressing to the specific member.

Further information on data access control and the effect it has on structure access can be found in

Logix 5000 Controllers I/O and Tag Data Programming

Manual, publication 1756-PM004.

parameters for structure

• To improve tag access performance and to simplify the task of accessing structured tags through a network, create UDTs for the data that needs to be accessed through the network with members of the types listed following only, and access the UDTs as a whole.

• Atomic tags

• Arrays of atomic tags

• Other UDTs of atomic tags

• Arrays of UDTs of atomic tags

See also

CIP Services and User-created Tags on page 37

Structures use a Tag Type Service Parameter that is different from the one used with atomic tags. Like atomic tags, writing to UDT-based tags as a whole (that is, the whole structure, not just individual members) requires supplying the proper value for this parameter in the service request to successfully write

to the tag. The value is also returned when the structure is read.

The Tag Type Service Parameter for structures is a 4-byte sequence. The first two bytes are the values A0 and 02, followed by the latter two bytes, which contain a 16-bit calculated field called a Structure Handle. When transmitted on the wire, it looks like this:

34 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

A0 02 Structure Handle Low Byte Structure Handle High Byte

The Structure Handle comes from Template instance attribute 1 of the template instance associated with the tag. It is a calculated field, but generally it is not necessary to calculate the value. Reading and understanding the

IMPORTANT

knows what data type is in what position.

Chapter 1 CIP services

template information provides all the required information about the structure makeup to unambiguously access it. With that understanding, the client application can use the Structure Handle value read from the template instance attribute 1, rather than calculating it. For more information about structure templates, see Chapter 2, CIP services and user-created tags.

When choosing to calculate a Structure Handle, the process used to calculate this value can be found on this website:

https://www.rockwellautomation.com/resources/downloads/rockwellautomat ion/pdf/sales-partners/technology-licensing/TypeEncode_CIPRW.pdf

In Logix controllers, arrays report the data type of its members. An array of an atomic type reports the corresponding 2 byte Tag Type Service Parameter, while an array of structures reports the corresponding 4 byte Tag Type Service Parameter.

Reading a structure before writing to it is one way to obtain the value for this parameter, but that does not provide any understanding of the structure makeup, which is critical information when manipulating structure data. Also, the Structure Handle value is not unique among structures. Some positional changes of members within an otherwise identical structure yield the same value. The correct way to access structures as a whole is to first read their template information and understand the data packing. This assures that the application

When reading the structure to get the Structure Handle value before writing to it, be aware that the results may be ambiguous. Reserve this method only in cases where the control system development is complete and no further data structure changes will be made.

See also

CIP Services and user-created tags on page 37

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 35

How tags are organized

Chapter 2

CIP Services and User-created Tags

This chapter describes processes that CIP clients use when interacting with Logix 5000 controller data. The processes are:

• Finding the controller-scope tags that are created in a Logix 5000 controller

• Isolating user created tags from system tags and identify structured tags

• Locating the structure template for a specific structure

• Determining the structure makeup of a specific structure

• Determining the data packing of the members of a structure when

accessed as a whole and not member by a member.

• Determining when to refresh the list of tags and structure information

in the controller

See also

How tags are organized in the controller on page 37

Symbol object on page 38

Template object on page 38

Creating and maintaining a symbol object list on page 40

A client application interacts with the symbol and template objects associated with tags in Logix 5000 controllers. Through this interaction, the client application determines:

• What tags are created

• If a tag is structure

• The structure members

• How the data is packed in a message when reading a structure

This diagram shows the two objects in the Logix 5000 controller that are associated with tags. A client application must use the attributes and services

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 37

Chapter 2 CIP Services and User-created Tags

Symbol object

Template object

of these objects to understand the tag data makeup when reading or writing to tags.

See also

Creating a tag creates an instance of the Symbol class (Class ID 0x6B) in the controller. The name of the tag is stored in attribute 1 of the instance. The

data type of the tag is stored in attribute 2.

Instances of the Symbol class defines a class-specific service with the name Get_Instance_Attribute_List. This service helps find an instance of the class, and enables retrieving the name and type attributes for each instance of the class.

CIP Services and User-created Tags on page 37

The member names for structures only exist in the template definition. It is acceptable for a user-defined data type template definition to contain members with the same names as other tags in the controller.

See also

CIP Services and User-created Tags on page 37

How tags are organized in the controller on page 37

When creating a user-defined data type, an instance of the Template object

(Class ID 0x6C) is created to hold information about the structure makeup. This instance of the template object provides information about the template structure such as:

• Its name.

• The member list.

• The number of members.

• The size of the structure when read or written.

• The Structure Handle.

38 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

The Get_Attribute_List service directed to the Template object allows the client application to retrieve one or more attributes from an instance of the Template class. Template instance attributes provide information about the

IMPORTANT

can be unpredictable.

Chapter 2 CIP Services and User-created Tags

template structure itself so the application can interpret what it receives when using the Template_Read service.

The Template Read service is used to retrieve the template structure information that describes the members of the structure, their ordering, and data types. This information is required when accessing a structured tag as an entire structure to understand the data packing in the message frame.

Other structures in the Logix 5000 controller, including Module-Defined, Add-On-Defined, and Predefined data types, are also described in instances of the Template object. Use the Logix Designer application to implement one of the following indirect methods to access individual member tags.

Access atomic or arrayed atomic members of Module-Defined, Add-OnDefined, or Predefined structure tags using one of the following methods:

• Create a corresponding atomic tag (or atomic member of a structured tag) and use ladder logic to periodically copy the atomic member of the structure to the atomic tag.

• Create an alias tag for the atomic member that needs to be accessed.

These tags are present in the Symbol object instances and can be accessed like any other atomic tag.

The previous methods are also used with structured tags of a user-defined data type that contain a nested Module-Defined, Add-On-Defined, or Predefined type member.

The information described in this manual about accessing and understanding structures should not be used to access complete Module-Defined structures, Predefined structures, Add-On-Defined structures, or system tags, whether they are stand alone, an alias, or nested within another user created tag. Tags of these types have rules for dealing with host members and mapping of BOOLS, which are beyond the scope of this document. If such structures are manipulated or accessed, results

The STRING data type is a form of Predefined structure that would normally be excluded after executing steps that are described later. It is also acceptable to create user-defined data type string structures, including Strings of the same format as the standard STRING. This allows external access to the string and avoids the issues of Predefined structures.

To access any atomic tag that is visible in the Logix Designer application Data Monitor, it is also acceptable to manually enter the full symbolic tag address (NAME in the Data Monitor) in the client software. This includes atomic members of any structure that are visible in Data Monitor. This only applies to visible atomic tags and atomic members of structured tags.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 39

See also

CIP Services and User-created Tags on page 37

Chapter 2 CIP Services and User-created Tags

information.

Create and maintain a

Client applications access atomic tags or atomic members of structured tags by:

symbol object list

Client applications identifying the available tags or accessing structures must identify the required tags for access before manipulating tag data. This information is used to identify the data type of each tag and enable the application to interpret the data value associated with the tag.

Update the list of information as required. User program changes frequently create or delete tags, and add, delete, and modify user-defined data types.

How tags are organized in the controller on page 37

• Identifying the name of the tags for accessing

• Learning what tags are present in the controller and enabling users to

select the desired data.

Tip: In certain scenarios, it is not necessary to read all symbol instances or interpret template information. For example, if the name of the tags are recognized and the Symbolic Segment Addressing method is used to access only atomic tags or atomic members of structured tags, it is not necessary to read all symbol instances or interpret the template

This procedure:

• Creates and maintain a list of controller-scope symbol objects in an Logix 5000 controller

• Associates each instance with a template object instance if it is a structured tag

• Eliminates the symbol instances of data that the client application does not access or manipulate

To create and maintain a symbol object list:

1. Find all controller-scope tags.

2. Isolate user-created tags from system tags.

3. Determine the makeup of the structures. Structure members are not separate Symbol instances.

4. Determine the data packing of structure members in a message.

5. Determine when Symbol Instances have changed.

See also

Step 1: Find user-created controller scope tags in a Logix 5000 controller on page 41

40 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Step 2: Isolate user-created tags from system tags/identifying structured tags on page 44

Step 3: Determine the structure makeup for a specific structure

on page 47

Step 1: Find user-created

controller scope tags in a

Retrieve all symbol

Step 4: Determine the data packing of the members of a structure

on page 53

Step 5: Determine when the tags list and structure information need refreshing on page 54

This section describes the process used to learn what controller-scoped tags are located in the Logix 5000 controller by retrieving the Symbol Name and Symbol Type attributes for each instance of the Symbol Object.

Chapter 2 CIP Services and User-created Tags

Logix 5000 controller

object instances

The Get_Instance_Attribute_List (0x55) service returns instance IDs for each created instance of the Symbol class, along with a list of the attribute data

associated with the requested attributes.

See also

CIP Services and User-created Tags on page 37

Retrieve all symbol object instances on page 41

Example of retrieving the first group of tags on page 42

Analysis on page 42

The maximum size of a packet does not return all instances and attributes in a single request. To retrieve all instances, the client application must issue a series of requests to the controller and adjust the starting instance with each request.

This sequence describes how client application retrieves all the instances:

1. Set initial instance to zero.

2. Send request.

3. When General Status = 06 is returned, there is more data to read. To determine the last instance sent in the reply, parse the data received from the Logix 5000 controller to find the last instance ID returned.

4. Add one to the instance number determined in step 3.

5. Send the request again using the new instance value in the Request Path.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 41

When General Status = 00 Success, then all the symbol instances that are created have been returned.

See also

CIP Services and User-created Tags on page 37

Step 1: Finding user-created controller scope tags in a Logix 5000 controller on page 41

Chapter 2 CIP Services and User-created Tags

Message Request Field

Bytes (in hex)

Description

Request Service

Get_Instance_Attribute_List Service (Request)

Request Path Size

Request Path is 3 words (6 bytes) long

Request Path

20 6B 25 00 00 00

Logical Segments: Class 0x6B, Instance 0 (starting instance)

02 00

Attribute 2 – Symbol Type

Message Reply Field

Bytes (in hex)

Description

General Status

Status of 06 means: Too Much Data

0D 00

16-bit Symbol Name Length

Example of retrieving the Analysis

The table shows the format of the initial service request, which starts with Symbol Object, Instance 0. This returns as much of the requested data as will

first group of tags

fit in the reply. Most controller programs require multiple attempts to get all the tags.

Request Data 02 00 Number of attributes to retrieve

01 00 Attribute 1 – Symbol Name

Reply Service D5 Get_Instance_Attribute_List Service (Reply)) Reserved 00

Extended Status Size 00 No extended status Reply Data 12 03 00 00 First 32-bit Instance ID

(The 1st Instance ID after the instance specified in the Request Path)

43 69 70 52 65 61 64 44 61 74 61 31

FF 8F Symbol Type 51 0E 00 00 Second 32-bit Instance ID

06 00 63 6F 75 6E 74 73

82 CF Symbol Type … Next … 34 5D 00 00 Last 32-bit Instance ID in this reply

0A 00 50 61 72 74 73 5F 44 65 73 74

C3 00 Symbol Type

Characters in the symbol name

16-bit Symbol Name Length Characters in the symbol name

See also

CIP Services and User-created Tags on page 37

Step 1: Finding user-created controller scope tags in a Logix 5000 controller on page 41

42 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Observe the analysis:

• The Reply Data includes the Instance ID along with the data values for attributes 1 and 2.

Message Request Field

Bytes

Description

Message Reply Field

Bytes (in hex)

Description

Reserved

Extended Status Size

No extended status

0F 00

16-bit Symbol Name Length

Chapter 2 CIP Services and User-created Tags

• The Symbol Name attribute is a variable length structure of type STRING that consists of a UINT character count followed by the single octet characters (ASCII encoded) in the name.

• The Symbol Type attribute is a WORD, which is a 16-bit string, representing the symbol data type that is described in the next step.

The example previously returned number of instances, starting with instance 0x0312 and ending with instance 0x5D34. Only instances that are created are returned. Gaps in the instance numbers will occur.

Any symbol instances that represent tags whose External Access is set to None are not included in the reply data.

See also

Continue the retrieval process on page 43

Continue the

In this example, assume that the controller has too many symbols to fit in one reply. The last instance number shown in the previous example is 0x5D34, and

retrieval process

incremented to 0x5D35.

This table shows the request for the next set of instances or attribute data. The value 0x5D35 is the starting instance ID in the path.

Request Service 55 Get_Instance_Attribute_List Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

Request Path 20 6B 25 00 35 5D Logical Segments: Class 0x6B, Instance 0 x5D35(starting instance) Request Data 02 00 Number of attributes to retrieve

01 00 Attribute 1 – Symbol Name 02 00 Attribute 2 – Symbol Type

The Logix 5000 controller retrieves data beginning with instance 0x5D35 and returns all of the data that fits in the message frame. The table lists examples of subsequent responses.

Reply Service D5 Get_Instance_Attribute_List Service (Reply)

General Status 06 Status of 06 means: Too Much Data

Reply Data 43 63 00 00 First 32-bit Instance ID

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 43

(The 1st Instance ID after the instance specified in the Request Path)

0C 00 43 69 70 52 65 61 64 44 61 74 61 33

FF 8F Symbol Type 54 72 00 00 Second 32-bit Instance ID

73 61 6D 70 6C 65 54 69 6D 65 5F 44 65 73 74

16-bit Symbol Name Length Characters in the symbol name

Characters in the symbol name

Chapter 2 CIP Services and User-created Tags

Message Reply Field

Bytes (in hex)

Description

Step 2: Isolate user-created

Symbol Type Attribute

83 8F Symbol Type … Next … E8 08 00 00 Last 32-bit Instance ID in this reply

13 00 50 72 65 67 72 61 6D 3A 4D 61 69 6E 50 72 6F 67 72 61

68 10 Symbol Type

The retrieval process is repeated until the General Status of 00 is received from the Logix 5000 controller, indicating the last of the data has been sent.

When the retrieval process is complete, the client has a list of these items.

16-bit Symbol Name Length Characters in the symbol name

• All the controller scope tags in the controller, including atomics, structures, arrays, and aliases

• Which instance of the Symbol class is associated with each controller scope tag

• Information about the data type of each controller scope tag, including whether it is a structured tag

tags from system tags/identifying structured tags

See also

Analysis on page 42

Once the application has retrieved the last of the data, the next step is to remove the system tags, Predefined tags, Add-On-Defined tags, and ModuleDefined tags. This is accomplished by interpreting the Symbol Type, Symbol Name, and structure Template Name, structure first Member Name, and the Type of each structure member.

See also

CIP Services and User-created Tags on page 37

Symbol Type Attribute on page 44

Eliminate tags by applying rules on page 46

44 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Tag Type

Symbol Type Attribute

Description

Bit 14

Bit 13

Meaning

1 1 3 dimension array

Chapter 2 CIP Services and User-created Tags

The Symbol Type value is decoded as follows:

Atomic and structured tags are differentiated by the value of bit 15. Do not access Symbols where bit 12 =1 is a system tag.

Atomic tag Bit 15 = 0, Bit 12 = 0 The value of bits 0-11 of the Symbol Type attribute

is the Tag Type Service Parameter used in the Read/Write Tag services.

Structured tag Bit 15 = 1, Bit 12 = 0 Bits 0-11 of the SymbolType attribute are the

instance ID of the template object that contains the structure definition for this tag.

For any tag type, the value of bits 13 and 14 indicates the dimensions of the tag as shown in this table:

0 0 0 dimensions (not an array) 0 1 1 dimension array

1 0 2 dimension array

The Template object contains information about structures and many instances of the object class created to hold structures associated with data inside the Logix 5000 controller. When creating new user-defined types creates a new instance of the object class. The instance ID numbers do not follow any order.

Structured tags are linked to the template object instance through the Symbol Type attribute. For this reason, it is not necessary to read all the instances of the Template class. Simply view the Symbol Type attribute. When Bit 12=0; Bit15=1, then Bits 0-11 represent the instance ID of the template associated with this tag.

For example, assume a MachineSummary tag exists in the controller the tag is a structure of type STRUCT_B. The Symbol Type attribute (attribute 2) for this tag has the value 0x82E9. Bit 15 is set, indicating this tag is a structured tag and Bit 12 is reset so it is not a reserved tag. The value of bits 0-11 is 0x2E9 is the instance ID of the Template object where the structure makeup of the tag is defined and the value is in the range of values that are accessed.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 45

Chapter 2 CIP Services and User-created Tags

Use instance ID 0x2E9 in the Step 3 example to retrieve the structure information for a tag of this type.

After gaining an understanding of interpreting the Symbol Type attribute, identify tags that are not user-created from those that are user-created.

See also

Step 2: Isolate user-created tags from system tags/identifying structured tags on page 44

Eliminate tags by applying rules

Beginning with the full list of symbol instances, eliminate tags that should not be accessed or manipulated by applying the following rules.

1. Discard tags that are not in these ranges (eliminates Predefined and

String)

• The Symbol Type, Bit 12=0, Bit 15=0, and Bits 0-11 range from 0x001-

0x0FF (atomics)

• The Symbol Type, Bit 12=0, Bit 15=1, and Bits 0-11 range from 0x100-

0xEFF (structures, not including Predefined)

2. Discard tags that contain these characters

• The Symbol Name contains leading double underscores (for

example, __ABC) (eliminates some system tags)

• The Symbol Name contains a colon (:) (for example, eliminates

Module-Defined tags)

3. For the structure tags that remain (bit 15=1), access the Templates and discard tags where the Template Name, or the name of the first member of the structure, contains leading double underscores or a colon (:) This eliminates Add-On-Defined tags and aliases of ModuleDefined tags.

For template details, see Step 3: Determining the structure makeup for a specific structure.

4. Locate any nested member structures within the remaining structures, by checking the Type of each member. For any nested structures, repeat the checks earlier for Type in valid range, Template Name and first Member Name, and discard the total structure if a check fails. Continue until all nested structures are checked.

See also

Step 3: Determining the structure makeup for a specific structure

on page 47

46 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Attribute

Description/Characteristics

4 • This is the number of 32-bit words

Data Type: UDINT

• Data Type: UDINT

Message Request Field

Bytes (in hex)

Description

Request Path Size

Request Path is 3 words (6 bytes) long

Request Path

20 6C 25 00 E9 02

Logical Segment Class 0x6C, Instance ID 0x02E9

Request Data

04 00

Attribute Count

01 00

Message Reply Field

Bytes (in hex)

Description

Step 3: Determine the

structure makeup for a

Example of reading

specific structure

Chapter 2 CIP Services and User-created Tags

Any remaining tag with the Symbol Type Bit 15 = 1 is a structured data type. The client application must read information from the Template object Instance ID associated with this tag. This Instance ID is the value of Symbol Type, Bits 0-11. Four attributes of this instance contain information about structured data types for a client application that interacts with a UDT-based

tag.

Read these Template Instance attributes, using the instance ID in the Request Path of the Get_Attribute_List service (0x03) to the Template class (0x6C).

1 • This is the Tag Type Parameter used in Read/Write Tag service

• Structure Handle

•

Data Type: UINT

2 • This is the number of structure members

• Template Member Count

•

Data Type: UINT

• Template Object Definition Size

•

5 • This is the number of bytes of the structure data

• Template Structure Size

The table that follows shows how to read the list of attributes for an instance of the Template Object associated with the STRUCT_B example.

See also

Example of reading template attributes on page 47

This is an example of reading template attributes.

template attributes

Request Service 03 Get Attributes, List Service (Request)

Request Data

04 00 05 00 02 00

Attribute List: Attributes 4, 5, 2 and 1 are requested

Reply Service 83 Get_Attributes_List Service (Reply)

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 47

The response in the table contains a count of the items requested, followed by a structured response for each item consisting of the attribute ID (16-bits), status of retrieval (16-bits), and the attribute data (size varies).

Chapter 2 CIP Services and User-created Tags

Reserved

General Status

Success

Reply Data

04 00

Count of Items returned

05 00

20 00 00 00

Attribute 5, Template Structure Size

Number of bytes transferred on the wire when the structure is read using the Read Tag service

04 00

Number of members defined in the structure

CD 9E

Calculated CRC value for members of the structure.

Error Code (Hex)

Extended Error (Hex)

Description of Error

0x04

0x0000

A syntax error was detected decoding the Request Path.

0x05

0x0000

Request Path destination unknown: probably instance number is not present.

0x06

N/A

Insufficient Packet Space: Not enough room in the response buffer for all the data.

attribute is 0x14.

attributes parameter.

Analysis

Extended Status Size 00 No extended status

04 00 00 00 IE 00 00 00

00 00

02 00 00 00

01 00 00 00

Attribute 4, Template Object Definition Size Status: 0000 = success Size of the template definition structure in 32-bit words

Status: 0000 = success

Attribute 2, Member Count Status: 0000 = success

Attribute 1, Structure Handle Status: 0000 = success

The error codes may be returned by the Get_Attribute_List service to the Template object.

0x0A N/A Attribute list error, generally attribute not supported. The status of the unsupported

0x1C N/A Attribute List Shortage: The list of attribute numbers was too few for the number of

0x26 N/A The Request Path Size received was shorter than expected.

See also

CIP Services and User-created Tags on page 37

Step 3: Determining the structure makeup for a specific structure

on page 47

With the information returned in the previous example, the client application now has all the information necessary to use the Template Read service to

retrieve the template member information.

• Attribute 4 (Template Object Definitions Size) will be used to calculate how much data to read when using the Template Read service (0x4C) to get the template definition structure from the Template instance. The service data includes the starting byte offset (initially = 0) and the number of bytes to read.

The number of bytes to read is calculated as: (Template Object Definition Size * 4) – 23.

48 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Structure data format

Chapter 2 CIP Services and User-created Tags

Use the entire size calculated here in the request, regardless of how big it is.

• The service handler in the Logix 5000 controller will only return as much data as will fit in the message frame, and uses the General Status = 06 to indicate more to read. The client can adjust the starting offset (that is, new starting offset = bytes received +1) and reissue this request, repeating the process until General Status = 0 is returned, indicating that all data has been read. For smaller structures, these extra steps may not be required, as all the data will fit in a single reply.

• The structure data returned by the Template Read service has the format shown in Structure data format.

See also

Structure data format on page 49

The structure data returned by the Template Read service has this format:

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 49

The response to the Template Read service is the Member Information in Contents of the member information.

See also

Contents of the member information on page 50

Chapter 2 CIP Services and User-created Tags

Contents of the

Example of retrieving Example

The first 32-bit value contains:

member information

• The lower 16-bits are the INFO value, which is one of these value:

• If the member is an atomic data type, the value is zero.

• If the member is an array data type, the value is the array size (max

65535).

• If the member is a Boolean data type, the value is the bit location

(0-31; 0-7 if mapped to a SINT).

• The upper 16-bits represent the data type.

• The second 32-bit value is the offset location of the member in the UDT

structure.

The offset given in the Member n offset value in the Example of retrieving member information topic is where the member is located in the stream of bytes returned from reading a tag of this type in the controller.

See also

Analysis on page 13

Example of retrieving member information on page 50

member information

This example uses the Template Read service to retrieve the member information for an instance of the Template object. This examples explains how to interpret the member information stored in the template instance.

The structure that is accessed in this example is a user defined structure named STRUCT_B that was defined with the following members:

• BOOL named pilot_on

• INT array of 12 elements named hourlyCount

• REAL named rate

A tag of the type STRUCT_B was created and given the name MachineSummary. This tag name is used in the following example. The instance ID used in this example was determined by examining the Symbol Type attribute of the tag MachineSummary, as described in Step 2: Isolating user-created tags from system tags/identifying structured tags. The Template Read service request and response to that instance is shown in the following examples.

See also

50 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Step 2: Isolating user-created tags from system tags/identifying structured tags on page 44

Read the structure information for the MachineSummary tag, which is the STRUCT_B user-defined type

Message Request Field

Bytes

Description

Request Path Size

Request Path is 3 words (6 bytes) long

Request Path

20 6C 25 00 E9 02

Logical Segment: Class 0x6C, Instance 0x02E9

Message Reply Field

Bytes

Description

Reserved

00 General Status

Success

00 00 00 00

Offset (00000000)

00 00 00 00

Offset (00000000) (bit 0 in the previous SINT)

1C 00 00 00

Member 4 info, type, offset:

Offset (0000001C)

bytes are sent on the wire.

68 6F 75 72 6C 79 43 6F 75 6E

Member 3 Name: This is the

hourlyCount

member.

Chapter 2 CIP Services and User-created Tags

Request Service 4C Read Template Service (Request)

Request Data 00 00 00 00

61 00

Offset to start reading from (should be zero, initially) The number of bytes to be read.

Reply Service CC Read Template Service (Reply)

Extended Status Size 00 No Extended Status Reply Data

00 00 C2 00

00 00 C1 00

0C 00 C3 20 04 00 00 00

Member 1 info, type, offset:

non-array (0000) SINT (00C2)

Member 2 info, type, offset:

bit 0 (0000) BOOL (00C1)

Member 3 info, type, offset:

12 element array (000c) INT (C3 20) Offset (00000004)

00 00 CA 00

53 54 52 55 43 54 5F 42 3B 6E 45 42 45 43 45 41 48 41

non-array (0000) REAL (00CA)

Template Name (STRUCT_B) The structure name precedes the 0x3B in the stream of bytes. All remaining bytes are outside the scope of this document.

5A 5A 5A 5A 5A 5A 5A 5A 5A 5A 53 54 52 55 43 54 5F 42 30 00

Member 1 Name: The Logix Designer application selects the name of the member for one or more members. The host member for the BOOL (Member

2) follows. Member 1 is sent on the wire but is not visible to the user in the Logix Designer application Data Monitor view. As indicated by the offset value for Member 3, three bytes of pad are inserted after the SINT for this host member, for data alignment. When reading or writing the structure, the pad

70 69 6C 6F 74 5F 6F 6E 00 Member 2 Name is the first member of the structure that is visible to the

pilot_on

user in the Logix Designer application Data Monitor view. This is the member. The Member 2 information from earlier in the packet indicates this is a BOOL type and the data offset is zero. The client identifies that the BOOL is part of the Member_1 at the zero data offset, and that this is bit 0 of that member. The other 7 bits of Member_1 are not used and are not visible. Member 2 is not sent separately on the wire because it is part of Member_1.

74 00 72 61 74 65 00 Member 4 Name: This is the

It is a DINT data type and is at offset 4.

rate

member. It is a REAL data type and is at

offset 1C.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 51

Chapter 2 CIP Services and User-created Tags

More about BOOLS in UDTs

The user-defined data type (UDT) Template Name string and structure member names, stored as null-terminated strings follow the member information. For a UDT structure, the Template Name string contains the Template Name followed by the characters ;n plus additional characters. This may also apply for some non-UDT structures. For other non-UDT structures, the semi-colon may be followed by other characters, or just a NULL instead of the semi-colon and characters. Non-UDT structures are beyond the scope of this publication and should not be accessed as whole structures.

In this example, the first and second members have the same offset. This is typical of how BOOL members are mapped into UDTs. The first member is the host member for the data described by the second member. The second member, which is the visible member, is seen in the Logix Designer application Data Monitor.

See also

Analysis on page 48

This description applies only to UDTs, not Module-Defined, Add-On-Defined or Predefined structures.

BOOLs in UDTs are typically mapped to a previous SINT (whose name begins with the prefix ZZZZZZZZZZ) in the structure data stream. This SINT does not appear in the Logix Designer application Data Monitor view. With SINT host members, if more than eight contiguous BOOLs are defined, multiple adjacent SINTs are created to hold them. The bits are mapped into each SINT beginning with bit 0 thru bit 7 for contiguous BOOLS. If BOOLS are defined non-contiguously in a UDT, they are mapped to more than one host member. The Member Offset in the Template identifies where the host SINT is located and the bit order of the BOOL in the SINT is determined by the order of the bit in the structure. The host member is sent on the wire when the tag is accessed, but the visible BOOL is only present in the structure definition to enumerate the value and is not part of what is sent on the wire.

Logix BOOL arrays are multiples of BOOL[32] and are implemented as a DWORD array.

To better understand structure encoding, see the information on structured definitions in the Logix 5000 Controllers Import/Export Manual

, publication

1756-RM084.

52 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

See also

Analysis on page 13

Message Request Field

Bytes

Description

Message Reply Field

Bytes

Description

General Status

Success

Extended Status Size

No Extended Status

Attribute 1. See Step 3.)

00 00

= hourlyCount[0] (array of INT)

01 00

= hourlyCount[1]

02 00

= hourlyCount[2]

03 00

= hourlyCount[3]

04 00

= hourlyCount[4]

Step 4: Determine the data

packing of the members of

Example of reading an

a structure when accessed

Chapter 2 CIP Services and User-created Tags

This example illustrates reading a structure to understand how data transmits. This example also shows the value for the accessed tag.

The MachineSummary structured tag is a STRUCT_B type tag. The members of the MachineSummary tag have these values:

as a whole

• pilot_on = 1

• hourlyCount[0] = 0x00

• hourlyCount[1] = 0x01

• hourlyCount[2] = 0x02

• …

• hourlyCount[11] = 0x0b

• rate = 1.0

See also

Example of reading an entire structure on page 53

The following is an example of reading an entire structure.

entire structure

Request Service 4C Read Tag Service (Request) Request Path Size 08 Request Path is 8 words (16 bytes) long

Request Path 91 0E 4D 61 63 68 69 6E

65 53 75 6D 6D 61 72 79

Request Data 01 00 Number of elements to read (1)

ANSI Ext. Symbol Segment for

Machine Summary

Reply Service CC Read Tag Service (Reply) Reserved 00

Reply Data A0 02 CD 9E =Tag Type Service Parameter (The Structure Handle, Template Instance

The data returned would be packed like this:

01 = host SINT (for BOOLs) 00 = Pad byte 00 = Pad byte 00 = Pad byte

05 00 = hourlyCount[5] 06 00 = hourlyCount[6]

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 53

Chapter 2 CIP Services and User-created Tags

Message Reply Field

Bytes

Description

08 00

= hourlyCount[8]

09 00

= hourlyCount[9]

0a 00

= hourlyCount[10]

0b 00

= hourlyCount[11]

00 00 80 3F

= rate (REAL)

How to detect changes

07 00 = hourlyCount[7]

The amount of data returned (0x20 bytes) agrees with the value of Attribute 5 (Template Structure Size = 0x20 as determined in Step 3) using the Get_Attributes_List service.

See also

Step 4: Determining the data packing of the members of a structure when accessed as a whole on page 53

CIP Services and User-created Tags on page 37

Step 5: Determine when the tags list and structure information need refreshing

The client application should periodically check for changes in the controller to determine if it must repeat the process outlined in this chapter. Once controller program development is complete, tags and UDT definitions generally remain constant; however, it is possible that a PLC program

developer may create or delete tags from time to time, or change a UDT definition. When that happens, the symbol object instance associated with a tag may change, the relationship between the template instance and the symbol instance may change, or the data makeup of a UDT-based tag can change.

See also

How to detect changes on page 54

Controller object attributes indicate changes made to the controller. A change

in these values indicates changes to symbol instances, template instances, or both. These are not the only changes indicated by these attributes, but these provide the most straightforward way to determine when the client application should refresh the list of created tags, while keeping the number of false indications to a minimum.

54 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

For client applications, use the Get_Attribute_List service to periodically retrieve attributes 1, 2, 3, 4 and 10 of class 0xAC in the controller. If the value of these attributes changes between reads, the client application must refresh the:

• List of symbols

• Association between symbols and templates

• Template information.

IMPORTANT

determining whether the tag information needs to be re-read.

Message Request Field

Bytes (in hex)

Description

Request Path

20 AC 25 00 01 00

Logical Segments: Class 0xAC, Instance 0x0001

0A 00

Attribute 10

Message Reply Field

Bytes (in hex)

Description

Reserved

General Status

Success

Extended Status Size

No extended status

05 00

Attribute value (INT)

02 00

Attribute number (attribute 2)

00 00

Success

Chapter 2 CIP Services and User-created Tags

To verify these attributes, use the Multi Service Packet Service (0x0a) to group the Get_Attribute_List service with the Read Tag services. If the situations occur, discard the Tag Read reply data and refresh the symbol and template information:

• The values returned for these attributes are different than the last time they were read.

• The General Status 0x05 (Path Not Known) is returned, which indicates that a project download is in progress.

Do not use the Multi Service Packet service to group the attribute check with the Tag Write service, as this would allow data to be written before

When writing to tags, prepare the tags to be written and then check the attributes. If no change is indicated and the General Status of the request is Success, proceed with writing the tag data. If a change is indicated, refresh the tag and template information as described. The tag write is followed by the attribute reads to confirm that the tag did not change before the write. If the attribute check fails, check the tag to confirm it did not change.

The client application should refresh this information after re-establishing the CIP network connection with the Logix 5000 controller, or if a General Status of 0x05 occurs when reading these attributes.

The service request and reply are shown as:

Request Service 03 Get_Attribute_List Service (Request) Request Path Size 03 Request Path is 3 words (6 bytes) long

Request Data 05 00 Number of attribute IDs that follow(5)

01 00 02 00 03 00 04 00

Attribute list: Attribute 1 Attribute 2 Attribute 3 Attribute 4

Reply Service 83 Get_Attributes_List Service (Reply)

Reply Data 02 00 Number of attribute responses that follow

01 00 Attribute number (attribute 1) 00 00 Success

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 55

Chapter 2 CIP Services and User-created Tags

Message Reply Field

Bytes (in hex)

Description

03 00

Attribute Number (Attribute 3)

00 00

Success

03 B2 80 C5

Attribute value (DINT)

04 00

Attribute Number (Attribute 4)

00 00

Success

03 B2 80 C5

Attribute value (DINT)

00 00

Success

F8 DE 47 B8

Attribute value (DINT)

The CPU Lock feature of Logix 5000 controllers causes this service request to return a General Status 0x10, Device State Conflict when the controller is password locked. In this state, controller memory can not be altered. Rockwell Automation suggests after receipt of the Device State Conflict for the first time, the client application should refresh the tag information one time. The client application should refresh again if the connection lost. The client application should reconnect after receipt of General Status 0x05, or a successful response to the service that indicates the CPU is unlocked.

01 00 Attribute value (INT)

0A 00 Attribute Number (Attribute 10)

See also

Step 5: Determining when the tags list and structure information need refreshing on page 54

56 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Data

01 00

Number of elements to read (1)

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

General Status

Success

Atomic Members of

Chapter 3

CIP Addressing Examples

The examples in this chapter show:

• Request Path strings for various data accesses using native CIP service requests and addressing.

• Only a portion of a message frame for requests and responses.

• How various references to atomic data types, arrays, and portions of

arrays are constructed.

Visit http://www.rockwellautomation.com/enabled/guides.html

• The traffic capture files that contain these services.

• The controller project file used as the target in these examples.

See also

Atomic Members of Predefined Data Types on page 57

Accessing User-Defined Structures on page 63

The examples access tags that return atomic data types.

Predefined Data Types

Read a single integer tag named parts. The tag has a data type of INT and a

Example 1 (Symbolic

value of 42.

Segment Addressing Method)

Request Service 4C Read Tag Service (Request) Request Path Size 04 Request Path is 4 words (8 bytes) long

Request Path 91 05 70 61 72 74 73 00 ANSI Ext. Symbolic Segment for

parts

to download:

Reply Service CC Read Tag Service (Reply) Reserved 00

Extended Status Size 00 No extended status Reply Data C3 00 INT Tag Type Value

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 57

Chapter 3 CIP Addressing Examples

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Message Request Field

Bytes (in hex)

Description - Symbol Instance Addressing

Request Path Size

Request Path is 3 words (6 bytes) long

Request Data

01 00

Number of elements to read (1)

Message Reply Field

Bytes (in hex)

Description - Symbol Instance Addressing

Reserved

General Status

Success

Extended Status Size

No extended status

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 7 words (14 bytes) long

…the Member segment for 5

Example 2 (Symbol

Example 3 (Symbolic

2A 00 0x002A= 42 decimal

See also

Atomic Members of Predefined Data Types on page 57

Read a single integer tag named parts.The tag has a data type of INT and a value of 42.

Instance Addressing Method)

Request Service 4C Read Tag Service (Request)

Request Path 20 6B

25 00 82 25

Reply Service CC Read Tag Service (Reply)

Reply Data C3 00 INT Tag Type Value

2A 00 002A = 42 decimal

Logical Segment for Symbol Class ID Logical Segment for Instance ID for tag

See also

Atomic Members of Predefined Data Types on page 57

Write the value of 14.5 to the 6th element of an array of REALs named setpoints(setpoints[5]).

Segment Addressing

parts

Method)

Request Service 4D Write Tag Service (Request)

Request Path 91 09 73 65 74 70 6F 69 6E 74 73 00 28 05 ANSI Ext. Symbolic Segment for

Request Data CA 00 REAL Tag Type Value

58 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

01 00 Number of elements to write (1) 00 00 68 41 0x41680000 = 14.5 decimal

setpoints

and

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

General Status

Success

Extended Status Size

No extended status

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Member Segment for 257

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Message Request Field

Bytes (in hex)

Description

Request Path Size

Request Path is 7 words (14 bytes) long

Example 4 (Symbolic

Example 5 (Symbol

Reply Service CD Write Tag Service (Reply)

Chapter 3 CIP Addressing Examples

See also

Atomic Members of Predefined Data Types on page 57

Read two elements of profile[0,1,257], which is a three dimensional DINT array The values of the tag are 572 and 50988.

Segment Addressing Method)

Request Service 4C Read Tag Service (Request) Request Path Size 09 Request Path is 9 words (18 bytes) long

Request Path 91 07 70 72 6f 66 69 6c 65 00

28 00 28 01 29 00 01 01

Request Data 02 00 Number of elements to read (2)

ANSI Ext. Symbolic Segment for Member Segment for 0 Member Segment for 1

profile

Reply Service CC Read Tag Service (Reply) Reserved 00

General Status 00 Success Extended Status Size 00 No extended status Reply Data C4 00 DINT Tag Type Value

F0 02 00 00 2C C7 00 00

0x000002F0 = 752 decimal 0x0000C72C=50988 decimal

See also

Atomic Members of Predefined Data Types on page 57

Read one element of profile[0,1,257] which is a three dimensional array of DINTs.

Instance Addressing Method)

Request Service 4C Read Tag Service (Request)

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 59

Chapter 3 CIP Addressing Examples

Message Request Field

Bytes (in hex)

Description

29 00 01 01

Member Segment of 257

Message Reply Field

Bytes (in hex)

Description

Reserved

00 General Status

Success

Reply Data

C4 00

DINT Tag Type Value

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

91 03 61 63 63 00

ANSI Ext. Symbolic Segment for

ACC

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Extended Status Size

No extended status

Example 6 (Symbolic

Request Path

Request Data 01 00 Number of elements to read (1)

20 6B 25 00 97 8A 28 00 28 01

Logical Segment for Symbol Class ID Logical Segment for Instance ID for tag Member Segment for 0 Member Segment for 1

Reply Service CC Read Tag Service (Reply)

Extended Status Size 00 No extended status

F0 02 00 00 0x000002F0 = 752 decimal

See also

Atomic Members of Predefined Data Types on page 57

profile

Read the accumulated value of a timer named dwell3 (dwell3.ACC).

Segment Addressing Method)

Request Service 4C Read Tag Service (Request) Request Path Size 07 Request Path is 7 words (14 bytes) long

Request Path 91 06 64 77 65 6C 6C 33

Request Data 01 00 Number of elements to read (1)

Reply Service CC Read Tag Service (Reply) Reserved 00

General Status 00 Success

Reply Data C4 00 DINT Tag Type Value

25 02 00 00 0x00000252 = 549 decimal

ANSI Ext. Symbolic Segment for

dwell3

60 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

See also

Atomic Members of Predefined Data Types on page 57

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 9 words (18 bytes) long

91 03 50 52 45 00

ANSI Ext. Symbolic Segment for

PRE

32 00 00 00

0x00000032 = 50 decimal

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reply Service

Read Tag Service (Reply)

Reserved

00 General Status

Success

Extended Status Size

No extended status

Message Request Field

Bytes (in hex)

Description- Symbol Instance and Symbolic Segment Addressing

Request Path Size

Request Path is 9 words (18 bytes) long

Message Reply Field

Bytes (in hex)

Description - Symbol Instance and Symbolic Segment Addressing

General Status

Success

Extended Status Size

No extended status

Example 7 (Symbolic Example 8 (Both

Write a preset value of 50 to the .PRE member of the counter ErrorLimit (ErrorLimit.PRE).

Segment Addressing Method)

Request Service 4D Read Tag Service (Request)

Chapter 3 CIP Addressing Examples

Request Path 91 0A 45 7272 6F 72 4C 69 60 69 74

Request Data C4 00

01 00

See also

Read the tag struct3.today.rate, which is a structure of type STRUCT_C, using both the Symbol Instance and Symbolic Segment Addressing methods.

Addressing Methods)

ANSI Ext. Symbolic Segment for

DINT Tag Type Value Number of elements to write (1)

ErrorLimit

Atomic Members of Predefined Data Types on page 57

Request Service 4C Read Tag Service (Request)

Request Path 20 6B

25 00 D1 18 91 05 74 6F 64 61 79 00 91 04 72 61 74 65

Request Data 01 00 Number of elements to read (1)

Reply Service CC Read Tag Service (Reply) Reserved 00

Reply Data CA 00 REAL Tag Type Service Parameter

00 00 80 41 16.0 decimal

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 61

Logical Segment for Symbol Class ID Logical Segment for Instance ID for tag ANSI Ext. Symbolic Segment for member ANSI Ext. Symbolic Segment for member

struct3

today rate

Chapter 3 CIP Addressing Examples

Message Request Field

Bytes (in hex)

Description - Symbol Instance and Symbolic Segment Addressing

Request Path Size

Request Path is 22 words (44 bytes) long

Message Reply Field

Bytes (in hex)

Description- Symbol Instance and Symbolic Segment Addressing

Reserved

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 10 words (20 bytes) long

Example 9 (Both

Example 10 (Symbolic

See also

Atomic Members of Predefined Data Types on page 57

Read the tag my2Dstruct4[1].today.hourlyCount[3] using both Symbolic Instance and Symbolic Segment Addressing methods.

Addressing Methods)

Request Service 4C Read Tag Service (Request)

Request Path 20 6B 25 00 4B 0D

28 00 91 07 6D 79 61 72 72 61 79 00 28 01 91 05 74 6F 64 61 79 00 91 0B 68 6F 75 72 6C 79 43 6F 75 6E 74 00 28 03

Request Data 01 00 Number of elements to read (1)

Logical Segments for Symbol Class ID and Instance ID for Element ID for element 0 ANSI Ext. Symbolic Segment for Element ID for element 1 ANSI Ext. Symbolic Segment for ANSI Ext. Symbolic Segment for Element ID for element 3

Reply Service CC Read Tag Service (Reply)

General Status 00 Success Extended Status Size 00 No extended status Reply Data C3 00 Data Type for INT

D0 5C 0x5CD0 = 23760 decimal

myarray

today hourlyCount

myDstruct4

Segment Addressing Method) with BOOLs

Request Service 4C Read Tag Service (Request)

62 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

See also

Atomic Members of Predefined Data Types on page 57

Read the value of a BOOL named struct2.pilot_on using Symbolic Segment Addressing. The value of the BOOL is 1.

The values for BOOL 0 and 1 returned by the controller are 0x00 and 0xFF respectively.

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

00 General Status

Success

Extended Status Size

No extended status

BOOL value for 1

Structure Name: STRUCT_A

Structure Name: STRUCT_B

Structure Name: STRUCT_C

Structure Name: STRUCT_D

Access User-Defined

Chapter 3 CIP Addressing Examples

Request Path 91 07 73 74 72 75 63 74 32 00

91 08 70 69 6C 6F 74 5F 6F 6E

Request Data 01 00 Number of elements to read (1)

Symbolic Segment for Symbolic Segment for

Reply Service CC Read Tag Service (Reply)

Reply Data C1 00 BOOL Tag Type Value

See also

Atomic Members of Predefined Data Types on page 57

This topic shows examples of accessing simple structures to help illustrate the message formats needed. The examples all use the Symbolic Segment

Structures

Addressing method. The four structure examples are defined and various members of the structures are accessed in the examples that follow.

struct2

pilot_on

Member Data Type limit4 BOOL

limit7 BOOL travel DINT

errors SINT wear REAL

Member Data Type hours_full BOOL

today STRUCT_B sampleTime DINT shipped DINT

For the controller project file and EtherNet/IP traffic capture files examples shown here, go to http://www.rockwellautomation.com/enabled/guides.html

See also

Member Data Type pilot_on BOOL

hourlyCount INT [12] rate REAL

Member Data Type myint INT

myfloat REAL myarray STRUCT_C[8] mypid REAL

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 63

Example 1 on page 64

Example 2 on page 64

Chapter 3 CIP Addressing Examples

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 5 words (10 bytes) long

Request Path

91 07 73 74 72 75 63 74 31 00

ANSI Ext. Symbolic Segment for

struct1

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

General Status

Success

Extended Status Size

No extended status

33 33 2B 41

wear member (REAL) = 10.7 decimal

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

91 04 77 65 61 72

ANSI Ext. Symbolic Segment for

wear

Message Reply Field

Bytes (in hex)

Description

General Status

Success

Example 1

Example 2

Example 3 on page 65

Example 4 on page 65

Example 5 on page 66

Read the tag struct1 that is a tag of type STRUCT_A. This reads the entire structure.

Request Service 4C Read Tag Service (Request)

Request Data 01 00 Number of elements to read (1)

Reply Service CC Read Tag Service (Reply) Reserved 00

Reply Data A0 02 C1 FA Tag Type for STRUCT_A

03 00 00 00 55 00 00 00 77 00 00 00

limit4 and limit7 members (bits 0 and 1 respectively) (BOOL) = 1, travel member (DINT) = 0x55 (85 decimal), errors member (SINT) = 0x77 (119 decimal),

See also

Access User-Defined Structures on page 63

Read the tag struct1.wear.

Request Service 4C Read Tag Service (Request) Request Path Size 08 Request Path is 8 words (16 bytes) long

Request Path 91 07 73 74 72 75 63 74 31 00

Request Data 01 00 Number of elements to read (1)

ANSI Ext. Symbolic Segment for

struct1

Reply Service CC Read Tag Service (Reply) Reserved 00

Extended Status Size 00 No extended status Reply Data CA 00 REAL Tag Type Value

64 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Message Reply Field

Bytes (in hex)

Description

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path Size

Request Path is 11 words (22 bytes) long

91 06 74 72 61 76 65 6c

ANSI Ext. Symbolic Segment for

travel

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

General Status

Success

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

28 04

Member Segment for element 4

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Example 3

Example 4

33 33 2b 41 0x412B3333=10.7 decimal

Chapter 3 CIP Addressing Examples

See also

Access User-Defined Structures on page 63

Read the tag str1Array[8].travel which is a one dimensional array of STRUCT_A.

Request Service 4C Read Tag Service (Request)

Request Path 91 09 73 74 72 31 41 72 72 61 79 00

28 08

Request Data 01 00 Number of elements to read (1)

Reply Service CC Read Tag Service (Reply) Reserved 00

Extended Status Size 00 No extended status Reply Data C4 00 DINT Tag Type Value

0F 27 00 00 0x0000270F=9999 decimal

ANSI Ext. Symbolic Segment for Member ID for element 8,

See also

Access User-Defined Structures on page 63

Read two elements of the tag struct2.hourlyCount[4], which is a structure of type STRUCT_B.

str1Array

Request Service 4C Read Tag Service (Request) Request Path Size 0D Request Path is 13 words (26 bytes) long

Request Path 91 07 73 74 72 75 63 74 32 00

Request Data 02 00 Number of elements to read (2)

Reply Service CC Read Tag Service (Reply) Reserved 00

General Status 00 Success

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 65

91 0B 68 6f 75 72 6c 79 43 6F 75 6E 74 00

ANSI Ext. Symbolic Segment for ANSI Ext. Symbolic Segment for

struct2

hourlyCount

Chapter 3 CIP Addressing Examples

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

06 00

0x0006=6 decimal

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Request Path

91 07 73 74 72 75 63 74 33 00

91 04 72 61 74 65

ANSI Ext. Symbolic Segment for

struct3

ANSI Ext. Symbolic Segment for

rate

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Extended Status Size

No extended status

Message Request Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Example 5

Example 6

Extended Status Size 00 No extended status Reply Data C3 00 INT Type Value

05 00

0x0005=5 decimal

See also

Access User-Defined Structures on page 63

Read the tag struct3.today.rate, which is a structure of type STRUCT_C.

Request Service 4C Read Tag Service (Request) Request Path Size 0C Request Path is 12 words (24 bytes) long

91 05 74 6F 64 61 79 00

Request Data 01 00 Number of elements to read (1)

ANSI Ext. Symbolic Segment for

Reply Service CC Read Tag Service (Reply) Reserved 00

General Status 00 Success

Reply Data CA 00 REAL Tag Type Value

00 00 80 41 0x41800000=16.0 decimal

See also

Access User-Defined Structures on page 63

Read the tag myDstruct4[0].myarray[1].today.hourlyCount[3] in the controller, which is a one dimensional array of type STRUCT_D.

today,

Request Service 4C Read Tag Service (Request) Request Path Size 19 Request Path is 25 words (50 bytes) long

Request Path 91 0A 6D 79 44 73 74 72 75 63 74 34

Request Data 01 00 Number of elements to read (1)

66 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

28 00 91 07 6D 79 61 72 72 61 79 00 28 01 91 05 74 6F 64 61 79 00 91 0B 68 6F 75 72 6C 79 43 6F 75 6E 74 00 28 03

ANSI Ext. Symbolic Segment for Element ID for element 0 ANSI Ext. Symbolic Segment for Element ID for element 1 ANSI Ext. Symbolic Segment for ANSI Ext. Symbolic Segment for Element ID for element 3

myDstruct4

myarray

today hourlyCount

Message Reply Field

Bytes (in hex)

Description - Symbolic Segment Addressing

Reserved

General Status

Success

Extended Status Size

No extended status

Chapter 3 CIP Addressing Examples

Reply Service CC Read Tag Service (Reply)

Reply Data C3 00 INT Tag Type Value

D0 5C 0x5CD0=23760 decimal

See also

Access User-Defined Structures on page 63

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 67

Name

Type

Description of Request Parameter

Semantics of Values

FNC

USINT

Fragmentation protocol function

See CIP Services on page 11.

Unconnected Messaging

Chapter 4

CIP Over the Controller Serial Port

The information in this chapter provides guidelines for communicating with ControlLogix controllers that use CIP over the serial port. For more information about DFI, see the

Manual, publication 1770-6.5.16. For more information about CIP services

used with Logix 5000 controllers, see CIP services.

The serial port of the controller supports the DF1 protocol and PCCC commands. Also deliver CIP messages and CIP services by encapsulating CIP explicit messages inside of the PCCC commands 0x0A and 0x0B.

PCCC has an inherent format limit of 244 bytes of application data. If an application sends a message larger than 244 bytes, it returns an error. The PCCC commands support a PCCC fragmentation protocol to allow the transmission of larger CIP messages (up to 510 bytes). For more information, see Fragmentation Protocol.

DF1 Protocol and Command Set Reference

(UCMM) through PCCC

CMD USINT Command = 0x0B STS USINT Status (0 in request) See the DF1 Protocol and Command Set TNSW UINT Used to match response with request

See also

CIP services on page 11

Unconnected Messaging (UCMM) through PCCC on page 69

Connected Explicit Messages through PCCC on page 70

Fragmentation Protocol on page 72

PCCC Command Code 0B provides CIP unconnected explicit-message capability over the controller's serial port. Use this for infrequent requests to the controller (for example, to read or write ControlLogix tags) or to establish an explicit message connection with the controller. See Connected Explicit

Messages through PCCC for connected communication.

The content of this PCCC message is a CIP explicit-message service request or response, such as those described earlier in this manual.

Reference Manual, publication 1770-6.5.16.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 69

Chapter 4 CIP Over the Controller Serial Port

Name

Type

Description of Request Parameter

Semantics of Values

Request Service

USINT

CIP Service Code

Request Path Size

USINT

Number of 16-bit words in the Request Path

Request Path

EPATH

Logical or Symbolic Segments, or both

varies

Name

Type

Description of Request Parameter

Semantics of Values

TNSW

UINT

Used to match response with request

Extended Status

Only present if Size > 0

size/ data type

Tip: Rockwell Automation assumes that you are familiar with CIP and the information related to CIP

http://www.rockwellautomation.com/enabled/cipetraining.html.

Connected Explicit

Extra USINT Additional information for fragmentation protocol

Service Request Data

Service data as defined by the service. Size and type

Similarly, the CIP service response is returned in a PCCC command reply, as shown in the following table.

CMD USINT Response = 0x0B + 0x40 See the DF1 Protocol and Command Set STS USINT Status (0 == Success)

FNC USINT Fragmentation protocol function See Fragmentation Protocol Extra USINT Additional information for fragmentation protocol Reply Service USINT CIP Service Code + 0x80 See CIP Services. Reserved USINT 00 General Status USINT ss

Extended Status Size USINT nn

Service Response Data

Service determines whether present or not, and the

Reference Manual, publication 1770-6.5.16.

Messages through PCCC

See also

Connected Explicit Messages through PCCC on page 70

CIP Services on page 11

Fragmentation Protocol on page 72

PCCC Command Code 0A provides CIP explicit-message connection behavior. The services are used within these commands. For example, the only difference between connected explicit messages through PCCC and an

EtherNet/IP explicit message connection is the wrapper that the CIP service is carried in. EtherNet/IP network uses Ethernet and TCP/IP technology and this uses DF1 and PCCC.

that is discussed here. The details of the CIP portions of the frame are not fully described here. References to where more detailed information can be found are provided later. If you are not familiar with CIP, a tutorial is available for purchase at

The table shows the fields used and where more information can be found about specific fields of the command structure.

70 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Name

Type

Description of Request Parameter

Semantics of Values

TNSW

UINT

Transaction sequence number

CID(2)

UINT

Connection ID

Determined in the Forward_Open request or reply.

Refer to the CIP Specification.

Chapter 4 CIP Over the Controller Serial Port

CMD USINT Command = 0x0A STS(1) USINT Status (0 in request)

FNC USINT Fragmentation protocol function See Extra USINT Additional information for fragmentation

protocol

Trans. Header ** UINT Transport class 3 Sequence Count Increments with each new data request, echoed in

Data - CIP Explicit Message See

See

the DF1 Protocol and Command Set Reference

Manual, publication 1770-6.5.16.

Fragmentation Protocol

One unique ID for requests and another for replies.

response. Refer to the CIP Specification.

CIP services

Establish the CIP explicit message connection before using the 0A command. This is accomplished by sending the 0B command to the controller with the CIP Forward_Open service request. The successful Forward_Open response provides the information for the fields shown later. The Forward_Open service is described in the CIP Specification and in the CIP tutorial.

The 0A command only supports Transport Class 3 connections to the Message Router object. No other transport classes are supported. The contents of the data field are CIP services that follow the CIP Service Request/Response Format.

Like all CIP connections, an RPI value associated with the connection establishes the rate at which messages must be sent. If they are not sent at this rate, timeouts occur. Rest the RPI timer should be reset when a message is sent. When the timer reaches the RPI value, the re-transmit the connection to the last sent message and keep the same sequence count. The target does not reprocess the message after it detects the same sequence count. The target resends the same response previously sent. The connection timeout has a short duration, and the recovery time from a noise or a temporary disconnect also has a short duration. It is recommended to scale the timeout for noise recovery to 20 seconds and then set the RPI rate productions to avoid allowing connections to time out repeatedly.

The PCCC status (STS) in the PCCC response indicates the success or failure of the PCCC system to deliver the data across the PCCC link. It does not indicate the success or failure of the CIP service in the reply. The status for that presents in the CIP service response, within the data field. See the CIP services for details.

Connections are usually kept open for very long periods of time. However, it may be necessary for the client to close the connection from time to time. In that case, the client application must close the connection using the 0B command with a CIP Forward_Close service request in it. It is not acceptable to allow connections to timeout naturally and clean themselves up.

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 71

Chapter 4 CIP Over the Controller Serial Port

Name

Type

Description of Request Parameter

Semantics of Values

DST

USINT

Address of destination

SRC

USINT

Address of source

00hex (

Only

function)

00hex (

Only

has no Extra)

Request Path Size

USINT

Number of 16-bit words in the Request Path

Request Path

EPATH

Logical or Symbolic Segments, or both

6.5.16.

Fragmentation Protocol

The following is an example of the fields for a CIP explicit message connection using a Class 3 Transport encapsulated in PCCC sent unfragmented, using DF1 Full Duplex on RS-232.

DLE USINT ASCII escape character See the DF1 Protocol and Command Set Reference STX USINT Start of message

CMD USINT Command = 0Ahex STS USINT Status (0 in request) See the DF1 Protocol and Command Set Reference TNSW UINT Transaction sequence number FNC USINT Fragmentation protocol function Fragmentation Protocol

Extra USINT Additional information for fragmentation protocol Fragmentation Protocol

CID UINT O-T Connection ID Refer to the CIP Specification Transport Header UINT Transport class 3 Sequence Count Request Service USINT CIP Service Code See

Manual, publication 1770-6.5.16.

CIP Services

Service Data DLE USINT ASCII escape character See the DF1 Protocol and Command Set Reference

ETX USINT End of message BCC or CRC USINT or UINT Block Check Character Cyclic Redundancy Check See the DF1 Protocol and

Command Set Reference Manual, publication 1770-

Service data

Manual, publication 1770-6.5.16.

See also

Fragmentation Protocol on page 72

CIP Service Request/Response Format on page 15

CIP services on page 11

The fragmentation protocol allows messages up to 510 bytes to be sent over

PCCC/DF1, which has an inherent limit of 240 bytes. It allows each fragment to be identified as it is transferred, with each fragment being acknowledged (Ack or Nak) before the next fragment is sent, and provides the ability for the client device to abort the fragmentation sequence if necessary. This fragmentation protocol is used only with the 0A and 0B PCCC commands.

72 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

For more information on the PCCC fragmentation protocol, go to

http://www.rockwellautomation.com/enabled/guides.html

IMPORTANT

To avoid data mismatch, use an array tag of the same data type as the PLC/SLC file.

Supported Subset of

Chapter 4 CIP Over the Controller Serial Port

See also

CIP Over the Controller Serial Port on page 69

PCCC Commands

PCCC commands are carried within DF1 packets to the serial port of the Logix 5000 controller. This option for accessing data table mappings inside the Logix 5000 controller is provided for backward compatibility with legacy controllers that do not understand CIP. CIP is the native language of a Logix 5000 controller. Other applications that worked with our legacy controllers over serial port could, with proper mapping of Logix 5000 tags to data tables, be used to access information in the Logix 5000 controller.

For details on mapping of tags to PLC/SLC data files or data tables, see the Logix

5000 Controllers Design Considerations Reference Manual, publication 1756-RM094.

CIP messaging is the preferred method of interacting with Logix 5000 controllers, but PCCC messaging is serviceable for many applications, especially where the legacy communications product is not able to be modified, and where the Logix 5000 customer is willing to do the extra configuration of data table mappings in the Logix 5000 controller. Remote applications that depend on serial communication over a modem or serial radio link can also use this method.

PCCC commands can also arrive at the controller in these ways:

• Through the RS-232 serial port

• Encapsulated inside a ControlNet message

• Encapsulated inside a EtherNet/IP message

This chapter identifies the PCCC commands supported by Logix and the formatting required. A license from ODVA is not required for you to use the PCCC commands described in this chapter.

See also

Supported Subset of PCCC Commands on page 73

Logix controllers support these subset of PCCC commands.

PCCC Commands

• PLC-2 Communication Commands on page 75

• Unprotected Read

• Protected Write

• Unprotected Write

• Protected Bit Write

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 73

Chapter 4 CIP Over the Controller Serial Port

All Requests Start with these Fields: [CMD] [STS] [TNS] [FNC]

[CMD] 1-byte, Request command code

• [FNC] 1 byte, function code (not included in some PLC2 commands)

All Replies Start with these Fields: [CMD] [STS] [TNS]+[EXT STS]

• only present if [STS]=0xF0

Initial Fields of All

• Unprotected Bit Write

PCCC Commands

• PLC-5 Communication Commands on page 77

• Read Modify Write

• Read Modify Write N

• Typed Read

• Typed Write

• Word Range Read

• Word Range Write

• Bit Write

• SLC Communication Commands on page 81

• SLC Protected Typed Logical Read with 3 Address Fields

• SLC Protected Typed Logical Write with 3 Address Fields

• SLC Protected Typed Logical Read with 2 Address Fields

• SLC Protected Typed Logical Write with 2 Address Fields

See also

PCCC Commands on page 73

This topic describes the initial fields present in all PCCC commands. These

fields are followed by command-specific fields

The name of each command is listed in this format:

Command Name (CMD=xx,yy; FNC=zz), where:

• xx= CMD code in the Request

• yy= CMD code in the Reply

• zz = Function code

•

• 0x0F in PLC-5 and SLC commands

• 0x0N in PLC2 commands (N is the hex value for the command)

• [STS] 1-byte, status code, 0x00 in commands

• [TNS] 16-bits, transaction identifier

• [CMD] 1-byte, Reply command code

• 0x4F in PLC-5 and SLC commands

• 0x4N in PLC2 commands (N is the same hex value in the corresponding Request CMD)

• [STS] 1-byte, status code

• 0x00 (success)

• 0xNN is error code (N is any hex value)

• 0xF0 means fourth field present (EXT STS] See following.

• [TNS] 16-bits, unique transaction identifier

• [EXT STS] 1-byte, extended status error code

74 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Request Format: [PLC-2 address] [size]

[PLC-2 address] 2-bytes; byte offset from start of file, on 16-bit boundary, low byte first

Reply Format: [data]

Request Format: [PLC-2 address] [data]

Reply Format:

no data-only status

Request Format: [PLC-2 address] [data]

• [data]

Reply Format:

PLC-2 Communication

Commands

Unprotected Read (CMD=01,

Protected Write (CMD=00,

Unprotected Write (CMD=08,

41; FNC not present)

Chapter 4 CIP Over the Controller Serial Port

See also

PCCC Commands on page 73

Use the PLC-2 commands to access one tag in a Logix 5000 controller. After

sending the command, it is acceptable to map the message to an INT(16 bit

integer) tag in the Logix 5000 controller. All the PLC2 commands access the

same tag, typically an INT array.

Logix Designer handles protected and unprotected commands the same way, whether the access for the data is set to Read/Write, Read Only, or None.

See also

PCCC Commands on page 73

This command provides the read capability for the PLC-2 commands.

•

[size] 1-byte; must be an even number of bytes

40; FNC not present)

[data] is up to 244 bytes

See also

PLC-2 Communication Commands on page 75

This Protected Write command provides a protected write capability for the

PLC-2 commands.

• [PLC-2 address] 2-bytes; byte offset from start of file, on 16-bit boundary, low byte first

•

[data]

See also

PCCC Commands on page 73

PLC-2 Communication Commands on page 75

This command provides a basic write capability for the PLC-2 commands.

48; FNC not present)

• [PLC-2 address] 2-bytes; byte offset from start of file, on 16-bit boundary, low byte first

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 75

Chapter 4 CIP Over the Controller Serial Port

Request Format: [PLC-2 address] [data]

Request Format: [PLC-2 address][SET mask] [RESET mask] + repeats(1)

Reply Format:

no data-only status

Request Format: [PLC-2 address] [SET mask][RESET mask] + repeats(1)

Reply Format:

no data-only status

Protected Bit Write

Unprotected Bit Write

no data-only status

See also

The Protected Bit Write (CMD=02, 42; FNC not present) command provides a

protected bit write capability for the PLC-2 commands.

(CMD=02, 42; FNC not

For each 3-field set, the command performs this sequence:

present)

PLC-2 Communication Commands on page 75

1. Copy the specified byte from limited areas of memory

2. Set the bits specified in the [SET mask]

3. Reset the bits specified in the [RESET mask]

4. Write the byte back.

• [PLC-2 address] 2-bytes; byte offset from start of file, on 16-bit boundary, low byte first

• [SET mask] is 1 byte (1=set to 1)

•

[RESET mask] is 1 byte (1=reset to 0)

(CMD=05, 45; FNC not present)

See also

PCCC Commands on page 73

PLC-2 Communication Commands on page 75

This command provides a bit write capability for the PLC-2 commands. For

each 3-field set, this command performs this sequence:

1. Copy the specified byte from limited areas of memory

2. Set the bits specified in the [SET mask]

3. Reset the bits specified in the [RESET mask]

4. Write the byte back.

• [PLC-2 address] 2-bytes; byte offset from start of file, on 16-bit boundary, low byte first

• [SET mask] is 1 byte (1=set to 1)

•

[RESET mask] is 1 byte (1=reset to 0)

See also

76 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

PLC-2 Communication Commands on page 75

IMPORTANT

Manual, publication 1770-6.5.16.

EXAMPLE

tag_name[x][y][z]

IMPORTANT

Use the PLC-5 file data type that matches the data type of the Logix tag.

To access

This entry is specified (1)

PCCC symbolic

setpoints[5]

PLC-5 Communication Addressing examples

Chapter 4 CIP Over the Controller Serial Port

Each PLC-5 command requires a system address in one of these forms:

Commands

• Logical binary or logical ASCII, which addresses data by file and element.

• The first level of the logical binary must be 0. This is required to

access controller-scoped tags.

• The second level is the file number. This is also the level following the letters in the logical ASCII form.

• The next 1, 2, or 3 levels correspond to the array dimension indices as follows: data[1][2][3].

• Any subsequent levels of logical address access parts of the complex types. See CIP data types

Logical addressing requires use of data table mapping. Use a Logix array tag that matches the data type of the PLC5 file. Members of SINT, INT, DINT, and REAL arrays are contiguous in Logix memory. For more information on Logical addressing, see the

DF1 Protocol and Command Set

• Symbolic, which addresses data directly by a tag name.

• The symbol string starts with a NULL character and ends with a

NULL character.

• In the simplest case, the symbol string consists of just the tag name.

• To address an array, delimit the array indices with square brackets.

The examples depict symbolic addresses.

Symbolic addresses: tag_name tag_name[x] tag_name[x,y,z]

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 77

The PLC-5 TYPED READ and TYPED WRITE commands access tags (elements) of SINT, INT, DINT, or REAL only. The other PLC-5 commands access only INTs, that is, 16-bit words.

See also

CIP data types on page 11

This table lists the addressing examples for PLC-5 PCCC Messages.

Single integer tag named The sixth element of the array of REALs named

setpoints

Single integer [2,5,257] of three dimensional array named

profile

parts

PCCCsymbolic parts

PCCC Logical ASCII $F8:6

PCCC Logical ASCII

PCCC symbolic profile[2,5,257]

$N7:2:5:257

Chapter 4 CIP Over the Controller Serial Port

Request Format: [PLC-5 system address] [AND mask] [OR mask] + repeats(1)

Reply Format:

no data-only status

Request Format: [no of sets][PLC-5 system address] [mask length][AND mask][OR mask]

• [OR mask] 2 or 4 bytes (low byte first) specifying which bits in the word to set (1= set to 1)

Reply Format: [data]

[data]

the Logix data format is not documented.

Read Modify Write N

Read Modify Write (CMD=0F, 4F; FNC=26)

For each 3-field sequence (address, AND mask, OR mask), this RMW command performs this procedure.

See also

1. Copy the specified word.

2. Reset the bits specified in the [AND mask].

3. Set the bits specified in the [OR mask].

4. Write the word back.

• [PLC-5 system address] specifies the word to be modified

• [AND mask] 2 bytes (low byte first) specifying which bits in the word to reset (0=reset to 0)

•

[OR mask] 2 bytes (low byte first) specifying which bits in the word to set (1=set to 1)

Read Modify Write N (CMD=0F, 4F; FNC=79) on page 78

(CMD=0F, 4F; FNC=79)

Typed Read (CMD=0F, 4F; FNC=68) on page 79

Typed Write (CMD=0F, 4F; FNC=67) on page 79

Word Range Read (CMD=0F, 4F; FNC=01) on page 79

Word Range Write (CMD=0F, 4F; FNC=00) on page 80

For each 4-field sequence, this RMW-N command performs this procedure:

1. Copy the specified word.

2. Reset the bits specified in the [AND mask].

3. Set the bits specified in the [OR mask].

4. Write the word back.

+repeats(1)

• [no of sets] indicates the number of sets of the following four fields.

• [PLC-5 system address] specifies the word to be modified

• [mask length] specifies 2 or 4 byte masks. For this command, most Logix controllers only support

4-byte mask; use RMW command (FNC=26) for 2-byte mask

• [AND mask] 2 or 4 bytes (low byte first) specifying which bits in the word to reset (0=reset to 0)

• For a successful command ([STS]=0x00), data may be returned, but the Logix data format is not

documented

• For an unsuccessful command ([STS]=0xF0), a byte (error code) occurs; data may be returned, but

78 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Request Format: [packet offset][total transaction][PLC-5 system address][size]

Reply Format: [Type/ID][data]

Request Format: [packet offset] [total transaction][PLC-5 system address] [type/ID] [data]

[data]

Reply Format:

Typed Read (CMD=0F,

4F; FNC=68)

Typed Write (CMD=0F,

Word Range Read (CMD=0F,

Chapter 4 CIP Over the Controller Serial Port

See also

PCCC Commands on page 73

PLC-5 Communication Commands on page 77

The typed read command reads a block of data starting at the PLC-5 system address plus the packet offset.

• [packet offset] 2 bytes, offset in number of elements

• [total transaction] 2 bytes, number of elements in complete transaction

• [PLC-5 system address]

•

[size] is 2 bytes; number of elements to return in this reply

• [Type/ID] 1 byte, (for integers) or 2 bytes (for float) type and size of elements

• SINT, INT, DINT (type: integer; size 1,2,4 bytes) REAL (type: float, size 4 bytes)

• For details about Type/ID encoding, see the DF1 Protocol and Command Set Reference Manual,

publication 1770-6.5.16. [data]

4F; FNC=67)

See also

PLC-5 Communication Commands on page 77

The typed write command writes a block of data starting at the PLC-5 system address plus the packet offset.

• [packet offset] 2 bytes, offset in number of elements

• [total transaction] 2 bytes, number of elements in complete transaction

• [PLC-5 system address]

• [type/ID] 1 byte (for integers) or by 2 bytes (for float), type and size of elements.

• SINT, INT, DINT (type: integer; size 1,2,4 bytes) REAL (type: float, size 4 bytes)

• Integer conversion; error if data value too large for target integer type (SINT or INT)

• For details about Type/ID encoding, see the DF1 Protocol and Command Set Reference Manual,

publication 1770-6.5.16.

•

no data, only status

See also

PLC-5 Communication Commands on page 77

The word range read command reads a block of words starting at the PLC-5 system address plus the word offset.

4F; FNC=01)

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 79

Chapter 4 CIP Over the Controller Serial Port

Request Format: [packet offset] [total transaction][PLC-5 system address] [size]

[size] is 1 byte, number of bytes and must be even in number

Reply Format: [data]

[data] up to 244 bytes

Request Format: [packet offset] [total transaction][PLC-5 system address] [data]

[packet offset] 2 bytes, offset in number of 16-bit words

[data]

Reply Format:

Request Format: [PLC-5 system address][SET mask][RESET mask]

Reply Format:

Word Range Write (CMD=0F,

Bit Write (CMD=0F, 4F;

• [packet offset] 2 bytes, offset in number of 16-bit words

• [total transaction] 2 bytes, number of 16-bit words in complete transaction

• [PLC-5 system address]

•

See also

The word range write command writes a block of words starting at the PLC-5 system address plus the word offset.

4F; FNC=00)

•

• [total transaction] 2 bytes, number of 16-bit words in complete transaction

• [PLC-5 system address]

•

PLC-5 Communication Commands on page 77

FNC=02)

no data; only status

See also

PLC-5 Communication Commands on page 77

The Bit Write (CMD=0F, 4F; FNC=02) command sets and resets bits in a single word specified by the PLC-5 logical address. It changes a single word in a command.

For the 3-field sequence, the Bit Write (CMD=0F, 4F; FNC=02) command:

• Copies the specified word.

• Sets the bits specified in the [SET mask].

• Resets the bits specified in the [RESET mask].

• Writes the word back.

• [PLC-5 system address] specifies the word to be modified.

• [SET mask] is 2 bytes (low byte first) specifying which bits in the word to set (1=set to 1)

•

[RESET mask] is 2 bytes (low byte first) specifying which bits in the word to reset (1=reset to 0)

no data; only status

See also

PLC-2 Communication Commands on page 75

80 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

IMPORTANT

For the SLC Typed Read and Typed Write commands, map the data files to Logix tags

In a

The element number is used as the

SLC Communication

Commands

SLC Protected Typed

Chapter 4 CIP Over the Controller Serial Port

The SLC commands use strictly a logical form of addressing (for example, file/element/sub-element). For details about mapping the SLC files to Logix 5000 tags, see the

Logix 5000 Controllers Design Considerations Reference

Manual, publication 1756-RM094.

Logix handles protected and unprotected commands the same way, whether the access for data is set to Read/Write, Read Only, or None.

of types INT, DINT, or REAL only. Use an SLC or MicroLogix file data type that matches the data type of the Logix tag.

For INT tags, use file type 85hex (Binary) or 89hex (Integer) For DINT tags, use file type 91hex (Long For REAL tags, use file type 8Ahex (Float) For more information on SLC file types, see the

Reference Manual, publication 1770-6.5.16.

- MicroLogix only

)

DF1 Protocol and Command Set

SLC logical addressing has a limited number of logical address levels so there are some special concerns.

One-dimension array Dimension index for addressing (data[elem]) Two-dimensional array Index of the second dimension and the first dimension index is 0

(data[0][elem])

Three-dimensional array Index of the third dimension and the first and second dimension

indices are both 0 (data[0][0][elem])

See also

SLC Protected Typed Logical Read with 3 Address Fields (CMD=0F, 4F; FNC=A2) on page 81

SLC Protected Typed Logical Write with 3 Address Fields(CMD=0F, 4F, FNC=AA) on page 82

SLC Protected Typed Logical Read with 2 Address Fields (CMD=0F, 4F; FNC=A1) on page 82

SLC Protected Typed Logical Write with 2 Address Fields (CMD=0F, 4F; FNC=A9) on page 83

PCCC Commands on page 73

The service is supported for compatibility with SLC modules. It reads data from the logical address.

Logical Read with 3 Address Fields (CMD=0F, 4F; FNC=A2)

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Chapter 4 CIP Over the Controller Serial Port

Request Format: [byte size][file number][file type][element number][sub-element number]

Reply Format: [data]

[data]

Request Format: [byte size][file number][file type][element number][sub-element number]

first

Reply Format:

Request Format: [byte size][file number][file type][element number]

Reply Format: [data]

[data]

SLC Protected Typed SLC Protected Typed

• [byte size] 1 byte, number of data bytes to be read

• [file number]1 byte for 0-254; for >=255, 3 bytes, 0xFF followed by 2-byte number, low byte first

• [file type] 1 byte. For file types and codes, see the DF1 Protocol and Command Set Reference Manual,

• [element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte first

• [sub-element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte

See also

This service is supported for compatibility with older modules. It writes to the logical address.

Logical Write with 3

publication 1770-6.5.16. Refer to

SLC Communication Command

first

SLC Communication Commands on page 81

PCCC Commands on page 73

Address Fields(CMD=0F, 4F, FNC=AA)

Logical Read with 2 Address Fields (CMD=0F, 4F; FNC=A1)

• [byte size] 1 byte, number of data bytes to be written

• [file number]1 byte for 0-254; for >=255, 3 bytes, 0xFF followed by 2-byte number, low byte first

• [file type] 1 byte. For file types and codes, see the DF1 Protocol and Command Set Reference Manual,

publication 1770-6.5.16. Refer to

SLC Communication Command

• [element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte first

•

[sub-element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte

no data-only access

See also

SLC Communication Commands on page 81

PCCC Commands on page 73

This read command provides a simpler version for reading data.

• [byte size] 1 byte, number of data bytes to be read

• [file number]1 byte for 0-254; for >=255, 3 bytes, 0xFF followed by 2-byte number, low byte first

• [file type] 1 byte. For file types and codes, see the DF1 Protocol and Command Set Reference Manual,

publication 1770-6.5.16. Refer to

SLC Communication Command

•

[element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte first

82 Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Request Format: [byte size][file number][file type][element number]

• [data]

Reply Format:

no data-only access

SLC Protected Typed

Logical Write with 2 Address Fields (CMD=0F, 4F; FNC=A9)

Chapter 4 CIP Over the Controller Serial Port

See also

SLC Communication Commands on page 81

PCCC Commands on page 73

This write command provides a simpler version for writing data.

• [byte size] 1 byte, number of data bytes to be written

• [file number]1 byte for 0-254; for >=255, 3 bytes, 0xFF followed by 2-byte number, low byte first

• [file type] 1 byte. For file types and codes, see the DF1 Protocol and Command Set Reference Manual,

publication 1770-6.5.16. Refer to

SLC Communication Command

• [element number] 1 byte, 0-254; 3 bytes for >=255, first byte=0xFF then 2-byte number, low byte first

See also

SLC Communication Commands on page 81

PCCC Commands on page 73

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 83

Index

Atomic members 57, 58, 59, 60, 61, 62

CIP 11, 15, 37, 57, 69 CIP Addressing Examples 57, 58, 59, 60,

61, 62

CIP, data types 12

Data structures, Logix 33

PCC Commands 73, 74, 75 PLC-2 Communication Commands 75, 76 PLC-5 Communication Commands 78, 79,

Tags 37, 38

User-defined structures, access 63, 64,

65, 66

Write Tag Fragmented Service Error Codes

Write Tag Fragmented Service, examples

26, 27 Write tag service error codes 25 Write Tag Servie, Examples 24

Read Modify Write Tag Service 30, 31 Read Modify Write Tag Service, error codes

31 Read tag error codes 19 Read Tag Fragmented Service Error Codes

23 Read Tag Fragmented Service, examples

20, 21 Read Tag Service 18

Segment encoding 14 Services supported by Logix5000

Controllers 16, 18, 19, 24, 25, 30 SLC Communicatino Commands 81, 82, 83 Structures, user-defined 63, 64, 65, 66 Symbol object list, create 41, 44, 47, 53,

54 Symbol object list, maintain 41, 44, 47,

53, 54

Rockwell Automation Publication 1756-PM020G-EN-P - September 2020 85

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Rockwell Automation Publication 1756-PM020G-EN-P - September 2020

Rockwell Automation 1756 ControlLogix, 1756 GuardLogix, 1769 CompactLogix, 1769 Compact GuardLogix, 1789 SoftLogix Programming Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Logix 5000 Controllers Data Access

Important User Information

Summary of Changes

Table of Contents

Studio 5000 environment

Additional resources

Preface

Legal notices

CIP Services Overview

CIP Data Types

Atomic data type sizes

Logix 5000 data

Tag type service parameter

Analysis

Segment Encoding

Logical Segments

Symbolic Segments

Services Supported by Logix 5000 Controllers

Read Tag Service

Example Using Symbolic Segment Addressing on page 18

Example Using Symbol Instance Addressing on page 18

Write Tag Service

Example Using Symbol Instance Addressing

Example Using Symbolic Segment Addressing on page 26

Read Modify Write Tag Service on page 30

Logix Data Structures

Work with Data Structures

How tags are organized in the controller on page 37

Symbol object

Template object

Retrieve all symbol object instances on page 41

Continue the retrieval process on page 43

Symbol Type Attribute

Eliminate tags by applying rules

Example of reading template attributes on page 47

Analysis

Structure data format

Example of retrieving member information on page 50

More about BOOLS in UDTs

Example of reading an entire structure on page 53

How to detect changes

Step 5: Determine when the tags list and structure information need refreshing

Atomic Members of Predefined Data Types on page 57

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Unconnected Messaging (UCMM) through PCCC on page 69

Connected Explicit Messages through PCCC on page 70

Fragmentation Protocol

PCCC Commands

Supported Subset of PCCC Commands on page 73

PLC-2 Communication Commands on page 75

Read Modify Write N (CMD=0F, 4F; FNC=79) on page 78

SLC Protected Typed Logical Read with 3 Address Fields (CMD=0F, 4F; FNC=A2) on page 81

Index