Allen-bradley 842E User Manual

842E EtherNet/IP™Absolute Encoder

User Manual

Important User Information

Solid-state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid-State Controls (publication

SGI 1.1 available from your local Rockwell Automation sales office or online at http://literature.rockwellautomation.com) describes some important differences between solid-state

equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid-state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable.

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 copyrighted publication, in whole or part, without written permission of Rockwell Automation, is prohibited.

Throughout this manual 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 personal injury or death, property
					damage, or economic loss.
					Identifies information that is critical for successful application and understanding of
	IMPORTANT
					the product.

ATTENTION Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequences.

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

BURN HAZARD Labels may be on or inside the equipment (for example, drive or motor) to alert people that surfaces may reach dangerous temperatures.

Rockwell Automation, Allen-Bradley, RSLinx, RSLogix, and RSLogix 5000 are trademarks of Rockwell Automation, Inc.

Trademarks not belonging to Rockwell Automation are property of their respective companies.

It is recommended that you save this user manual for future use.

		Table of Contents
	About this document
	Who should use this manual . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . iii
	Purpose of this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . iii
	Related documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . iii
	Common techniques used in this manual . . . . . . . . . . . . .	. . . . . . . . . . . . . . iii
	Chapter 1
Safety	Authorized personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 1
	Correct use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 1
	General safety notes and protective measures . . . . . . . . . .	. . . . . . . . . . . . . . . 2
	Environmental protection . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 2
	Chapter 2
Encoder overview	Overview of the encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 3
	What is an encoder? . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 3
	What are the different kinds of encoders?. . . . . . . . . .	. . . . . . . . . . . . . . . 3
	842E encoder features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 4
	Configurable parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 5
	The electronic data sheet file . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 5
	Chapter 3
EtherNet/IP overview	Use of the Common Industrial Protocol . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 7
	TCP/IP and UDP/IP . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 8
	MAC address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 8
	Communication frame. . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . 8
	Understanding the producer /consumer model . . . . . . . .	. . . . . . . . . . . . . . . 9
	Specifying the requested packet interval . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 10
	EtherNet/IP topologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 10
	Star topology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 10
	Linear topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 11
	Device level ring topology . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 11
	CIP object model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 12
	Chapter 4
Installation	Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 17
	Shaft rotation direction . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 17
	Mounting with a solid shaft . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 17
	Mounting with a hollow shaft . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 18
	Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 19
	Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 19
	Electrical wiring instructions . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 19
	Pin assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 20
	Preset push button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 20
	Network address switches . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 20
	Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . 21

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Table of Contents

Configuring the encoder for your EtherNet/IP network

Chapter 5

Setting the IP Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Assigning the last octet in an IP address scheme of 192.168.1.xxx using the network address switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Assigning the IP Address using BootP/DHCP:. . . . . . . . . . . . . . . . . . 24

Configuring the 842 E encoder using RSLogix 5000

Chapter 6

Example: setting up the hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Configuring the encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Setting up the add-on profile in RSlogix 5000. . . . . . . . . . . . . . . . . . . . . . . 29 General tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Ethernet address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Module definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Connection tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Module Info tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Configuration tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Internet Protocol tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Network tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Default encoder settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Preset function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 RSLogix 5000 controller tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

	Chapter 7
Diagnostics and troubleshooting	Status indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	43
	Self-test via EtherNet/IP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	45
	Warnings, alarms and errors via EtherNet/IP . . . . . . . . . . . . . . . . . . . . . . .	45
	Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	46
	Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	46
	Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	47
	Appendix A
Installing the add-on profile	Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	49
	Performing the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	49
	Appendix B
RSLogix 5000 sample code	Linear scaling example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	53
	Setting up your project. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	54
	Using an explicit message configuration to set preset encoder value . . .	59
	Using an explicit message configuration to read preset encoder value . .	63
	Using an explicit message configuration to obtain the encoder’s run-time
	in seconds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	67

ii	Rockwell Automation Publication 842E-UM001A-EN-P May 2012

About this document

Read this section to familiarize yourself with the rest of the manual. It provides information concerning:

•Who should use this manual

•The purpose of this manual

•Related documentation

•Conventions used in this manual

Who should use this manual Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use 842E EtherNet/IP™ encoder.

You should have a basic understanding of electrical circuitry and familiarity with relay logic. If you do not, obtain the proper training before using this product.

Purpose of this manual

This manual is a reference guide for the 842E EtherNet/IP encoders. It describes the procedures you use to install, wire, and troubleshoot your encoder. This manual:

•Gives you an overview of the 842E EtherNet/IP encoders

•Explains how to install and wire your encoder

Related documentation	The following documents contain additional information concerning Rockwell
	Automation products. To obtain a copy, contact your local Rockwell Automation
	office or Allen-Bradley® distributor.
	Resource	Description
	Installation Instructions	Pub. # 10000169360
	842E EtherNet/IP Multi-turn Encoders
	EtherNet/IP Modules in Logix5000 Control Systems	A manual on how to use EtherNet/IP modules with Logix5000
	User Manual, publication ENET-UM001	controllers and communicate with various devices on the
		ethernet network
	Getting Results with RSLogix™ 5000,	Information on how to install and navigate RSLogix 5000. The
	publication 9399-RLD300GR	guide includes troubleshooting information and tips on how to
		use RSLogix 5000 effectively.
	M116 On-Machine Connectivity Catalog,	An article on wire sizes and types for grounding electrical
	M116-CA001A	equipment
	Allen-Bradley Industrial Automation Glossary,	A glossary of industrial automation terms and abbreviations
	AG-7.1

Common techniques used in this manual

The following conventions are used throughout this manual:

•Bulleted lists such as this one provide information, not procedural steps.

•Numbered lists provide sequential steps or hierarchical information.

•Italic type is used for emphasis.

Rockwell Automation Publication 842E-UM001A-EN-P May 2012

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About this document

Notes:

iv	Rockwell Automation Publication 842E-UM001A-EN-P May 2012

Chapter 1

Safety

This chapter deals with your own safety and the safety of the equipment operators.

Please read this chapter carefully before working with the 842E EtherNet/IP encoder or the machine or system in which the 842E EtherNet/IP encoder is used.

Authorized personnel

ATTENTION

The 842E EtherNet/IP encoder must only be installed, commissioned, and serviced by authorized personnel.

Repairs to the 842E EtherNet/IP encoder are only allowed to be undertaken by trained and authorized service personnel from Rockwell Automation.

The following qualifications are necessary for the various tasks:

Activity	Qualification
Mounting	Basic technical training
	Knowledge of the current safety regulations in the
	workplace
Electrical installation	Practical electrical training
and replacement	Knowledge of current electrical safety regulations
	Knowledge on the use and operation of devices in the
	related application (e.g., industrial robots, storage, and
	conveyor technology)
Commissioning,	Knowledge on the current safety regulations and the use
operation, and	and operation of devices in the related application
configuration	Knowledge of automation systems (e.g. Rockwell
	ControlLogix controller)
	Knowledge of EtherNet/IP
	Knowledge of the usage of automation software (e.g.
	Rockwell RSLogix)

Correct use

The 842E EtherNet/IP encoder is an instrument that is manufactured in accordance with recognized industrial regulations and meets the quality requirements as per ISO 9001:2008 as well as those of an environment management system as per ISO 14001:2009.

An encoder is a device for mounting that cannot be used independent of its foreseen function. For this reason an encoder is not equipped with immediate safe devices.

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Chapter 1	Safety

General safety notes and protective measures

Considerations for the safety of personnel and systems must be provided by the constructor of the system as per statutory regulations.

Due to its design, the 842E EtherNet/IP encoder can only be operated within an EtherNet/IP network. It is necessary to comply with the EtherNet/IP specifications and guidelines for setting up a EtherNet/IP network.

In case of any other usage or modifications to the 842E EtherNet/IP, e.g. opening the housing during mounting and electrical installation, or in case of modifications to the Rockwell Automation software, any claims against Rockwell Automation under warranty will be rendered void.

		Please observe the following procedures in order to ensure the correct and safe
ATTENTION
		use of the 842E EtherNet/IP encoder.

The encoder is to be installed and maintained by trained and qualified personnel with knowledge of electronics, precision mechanics and control system programming. It is necessary to comply with the related standards covering the technical safety stipulations.

All safety regulations are to be met by all persons who are installing, operating or maintaining the device:

•The operating instructions must always be available and must always be followed.

•Unqualified personnel are not allowed to be present in the vicinity of the system during installation.

•The system is to be installed in accordance with all applicable safety regulations and the mounting instructions.

•All work safety regulations of the applicable countries are to be followed during installation.

•Failure to follow all applicable health and safety regulations may result in personal injury or damage to the system.

•The current and voltage sources in the encoder are designed in accordance with all applicable technical regulations.

Environmental protection	Please note the following information on disposal.
	Assembly	Material	Disposal
	Packaging	Cardboard	Waste paper
	Shaft	Stainless steel	Scrap metal
	Flange	Aluminum	Scrap metal
	Housing	Aluminum Die-cast	Scrap metal
	Electronic assemblies	Various	Hazardous waste

2	Rockwell Automation Publication 842E-UM001A-EN-P May 2012

Chapter 2

Encoder overview

	The 842E family of encoders uses EtherNet/IP technology to provide its data to
	a programmable controller. These encoders include an embedded EtherNet/IP
	switch to connect additional EtherNet/IP capable products in series and/or
	support a device level ring (DLR) topology for ethernet media redundancy.
	The 842E are ultra-high resolution encoders in single-turn and multi-turn
	versions. These encoders have 18 bit single-turn resolution. The multi-turn has
	an additional 12 bits for counting the number of revolutions.
Overview of the encoder	What is an encoder?
	Encoders can electronically monitor the position of a rotating shaft to measure
	information such as speed, distance, RPM, and position. Rockwell Automation
	offers a variety of lightand heavy-duty incremental and absolute encoders. Our
	accessories help you easily install and efficiently use our encoders.
	What are the different kinds of encoders?
	Incremental
	A simple and cost-effective solution for a wide variety of applications,
	incremental encoders electronically monitor the position or speed of a rotating
	shaft. Encoder feedback is compatible with programmable controllers, numerical
	controllers, motion controllers, and other positioning systems. Rockwell
	Automation offers light-duty and heavy-duty incremental encoders for differing
	shaft loads. Ruggedized incremental encoders are available with an enclosure
	rating of NEMA Type 4 and IP66. Incremental encoders are also available in
	solid and hollow shaft models for a variety of mounting options. Applications
	include: machine tools, packaging machinery, motion controls, robotics, and DC
	drives.
	Absolute
	An absolute encoder has a unique digital output for each shaft position. The use
	of absolute encoders assures that true position is always available, regardless of
	power interruptions to the system. Absolute encoders can be single-turn or multi-
	turn.

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Chapter 2	Encoder overview
		Multi-turn units assign a unique digital output for each shaft position across
		multiple shaft rotations and are capable of extremely high resolutions. Rockwell
		Automation absolute encoders are available with an enclosure rating of NEMA
		Type 4 and IP66, as well as a variety of mounting options. Applications include
		steel mills, overhead cranes, punch presses, transfer lines, oil rigs, wind mills,
		machine tools, and packaging.
		Sine-cosine
		A sine-cosine encoder is a position transducer using two sensors, each 90° out of
		phase with respect to the other. Sine-cosine encoders can be used directly by the
		drive or squared to provide a conventional A quad B digital signal. Therefore, the
		sine-cosine encoder can be used as an absolute, sine-cosine, or incremental
		feedback device.
		Single-turn vs. multi-turn
		Absolute encoders are either single-turn or multi-turn. Single-turn encoders are
		used if the absolute position of the shaft for one revolution is required. Multi-
		turn encoders are used if the absolute position is required for more than one shaft
		revolution.
842E encoder features		The 842E EtherNet/IP encoder features include:

• Support for the encoder profile 22h (0x22) defined in the Common Industrial Protocol (CIP™), according to IEC 61784-1

• Compatibility with star, linear and device level ring topology

• Robust nickel code disk for harsh ambient conditions

• Configurable resolution per revolution: 1 to 262,144

• High precision and availability

• Ball bearing spacing of 30 mm for longer life

• Face mount flange and servo flange/blind hollow shaft and through hollow shaft

• 18-bit single turn resolution

• 30-bit total resolution multi-turn resolution

4	Rockwell Automation Publication XXXX-X.X.X - Month Year

Encoder overview	Chapter 2

Configurable parameters

The electronic data sheet file

The EtherNet/IP technology allows for certain encoder parameters to be configured over the network.

•Counting direction

•Counts per revolution

•Preset value

•Velocity output

•IP addressing

The electronic data sheet (EDS) file contains all the information related to the measuring-system-specific parameters as well as the operating modes of the 842E EtherNet/IP encoders. The EDS file is integrated using the EtherNet/IP network configuration tool to configure and place in operation the 842E EtherNet/IP encoder

For more information, go to www.rockwellautomation.com/resources/eds/ and search on “842E.”

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Chapter 2 Encoder overview

Notes:

6	Rockwell Automation Publication XXXX-X.X.X - Month Year

Chapter 3

Use of the Common

Industrial Protocol

EtherNet/IP overview

Ethernet Industrial Protocol (EtherNet/IP) is a frame-based computer networking technology for local industrial area networks. It follows the seven layers of the Open Systems Interconnection model:

OSI Model

		Layer	Function
		7. Application	Network process to application
	Host Layers	6. Presentation	Data, encryption
		5. Session	Inter-host communication
			Explicit and implicit messaging
		4. Transport	Flow control, TCP/UDP
	Media	3. Network	Internet protocol, logical addressing
		2. Data Link	Physical addressing
	Layers
		1. Physical	Media, signal and binary transmission, peer-to-peer, multicast, unicast

EtherNet/IP implements the Common Industrial Protocol (CIP), the application layer protocol specified for EtherNet/IP.

EtherNet/IP uses the CIP on the process layer. Similarly, as, for example, FTP is used for the transfer of files, this protocol is used for process control. The 842E encoder meets the requirements of the EtherNet/IP protocol according to IEC 61784-1 and those of the encoder profile.

	FTP	CIP	HTTP	Process layer
	TCP		UDP
	Explicit messagin g		Implicit messaging	Communication
				layers
		IP
		Ethernet		Physical layer

The encoder is an I/O adapter in the EtherNet/IP. It receives and sends explicit and implicit messages either cyclic or on request (polled).

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Chapter 3 EtherNet/IP overview

TCP/IP and UDP/IP

EtherNet/IP uses TCP/IP or UDP/IP for communication. (TCP is transmission control protocol and UDP is user datagram protocol.)

Implicit messaging is used for real-time communication between a programmable logic controller (PLC) and the encoder in EtherNet/IP. With implicit messaging a connection is established between exactly two devices within the CIP to transfer, for example, I/O data such as position or velocity from the encoder to the PLC. Implicit messaging uses UDP/IP via port 2222. As a result, a fast data rate is used.

Explicit messaging is used in EtherNet/IP for communication that does not need to take place in real time. Explicit messaging uses TCP/IP; it is used, for example, to transfer parameters from the PLC to the encoder.

MAC address

Devices that originate or use data on the network have factory-assigned media access control (MAC) addresses for unique identification. The MAC address (MAC ID) consists of 6 bytes. The first three bytes identify the manufacturer. The last three bytes are unique to the device. An example of a MAC address is 00:00:BC:C9: D7:14.

Communication frame

EtherNet/IP is based on the standard ethernet FRAME. This contains the ethernet header, the ethernet data and the ethernet trailer. The MAC addresses of the receiver (destination address) and of the source (source address) are contained in the ethernet header.

Transmission sequence

Header

Data field

Trailer

Destination Source

Address Address

46...1500 Byte

8	Rockwell Automation Publication 842E-UM001A-EN-P May 2012

EtherNet/IP overview	Chapter 3

Understanding the producer/consumer model

The ethernet data field consists of several nested protocols:

•The IP datagram is transported in the user data of the ethernet data field.

•The TCP segment or the UDP datagram are transported in the user data of the IP datagram.

•The CIP protocol is transported in the user data of the TCP segment or of the UDP datagram.

IP header	TCP/UDP header	CIP header	CIP data

CIP protocol

TCP segment or UDP datagram

IP datagram

CIP is a message-based protocol that implements a relative path to send a message from the “producing” device in a system to the “consuming” devices.

The producing device contains the path information that steers the message along the proper route to reach its consumers. Because the producing device holds this information, other devices along the path simply pass this information; they do not need to store it.

This has two significant benefits:

•You do not need to configure routing tables in the bridging modules, which greatly simplifies maintenance and module replacement.

•You maintain full control over the route taken by each message, which enables you to select alternative paths for the same end device.

The CIP “producer/consumer” networking model replaces the old source/ destination (“master/slave”) model. The producer/consumer model reduces network traffic and increases speed of transmission. In traditional I/O systems, controllers poll input modules to obtain their input status. In the CIP system, input modules are not polled by a controller. Instead, they produce their data either upon a change of state or periodically. The frequency of update depends upon the options chosen during configuration and where on the network the input module resides. The input module, therefore, is a producer of input data and the controller is a consumer of the data.

The controller can also produce data for other controllers to consume. The produced and consumed data is accessible by multiple controllers and other devices over the EtherNet/IP network. This data exchange conforms to the producer/consumer model.

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Chapter 3 EtherNet/IP overview

Specifying the requested packet interval

EtherNet/IP topologies

The requested packet interval (RPI) is the update rate specified for a particular piece of data on the network. This value specifies how often to produce the data for that device. For example, if you specify an RPI of 50 ms, it means that every 50 ms the device sends its data to the controller or the controller sends its data to the device.

RPIs are only used for devices that exchange data. For example, a ControlLogix EtherNet/IP bridge module in the same chassis as the controller does not require an RPI because it is not a data-producing member of the system; it is used only as a bridge to remote modules.

The 842E encoders can be connected in any of three network topologies: star, linear or device level ring (DLR).

IMPORTANT Rockwell Automation recommends that you use no more than 50 nodes on a single DLR or linear network. If your application requires more than 50 nodes, we recommend that you segment the nodes into separate, but linked, DLR or linear networks.

Star topology

The star structure consists of a number of devices connected to a central switch.

IMPORTANT When this topology is used, make the ethernet connection on the 842E encoder to the Link 1 connection. The Link 2 ethernet connection must remain unused.

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Linear topology

The linear topology uses the embedded switching capability to form a daisychain style network that has a beginning and an end. Linear topology simplifies installation and reduces wiring and installation costs, but a break in the network disconnects all devices downstream from the break. When this topology is used, both ethernet connections on the encoder may be used. For the network connection use Link 1, Link 2, or both.

Device level ring topology

A DLR network is a single-fault-tolerant ring network intended for the interconnection of automation devices. DLR topology is advantageous as it can tolerate a a break in the network. If a break is detected, the signals are sent out in both directions. With this topology, use both the Link 1 and Link 2 ethernet connections on the 842E encoder.

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CIP object model

EtherNet/IP uses an object model for network communication wherein all functions and data of a device are defined. The important terms are as follows:

Class: A class contains related objects of a device, organized in instances.

Instance: An instance consists of different attributes that describe the properties of the instance. Different instances of a class have the same services, the same behavior, and the same attributes. They can, however, have different values.

Attribute: The attributes represent the data a device provides over EtherNet/IP. These include the current values of, for example, a configuration or an input. Typical attributes are configuration and status information.

Service: Services are used to access classes or the attributes of a class or to generate specific events. These services execute defined actions such as reading the attributes.

The following table shows an example of the object model for the 842E encoders.

Class	Instance	Attribute	Value
842E	Basic	Resolution per revolution	15 bit
		Revolutions, total	12 bit
	Advanced	Resolution per revolution	18 bit
		Revolutions, total	12 bit

The 842E EtherNet/IP encoder supports the following classes of the encoder profile:

Supported classes

			Number of
Class code	Object class	Description	instances
0x01	Identity object	Contains information on the node within the network	1
0x02	Message router object	Processes all messages and routes them to the	1
		appropriate objects
	Assembly object	Assembles attributes (data) of various objects to a	7
		single object
0x04	(I/O-assembly class)
		Used for I/O messages
0x06	Connection manager object	Contains connection specific attributes for triggering,	1
		transport, and connection type
0x23	Position sensor object	Administrates device specific data like position and	1
		counting direction
0x47	Device level ring (DLR) object	Contains the configuration and status information of	1
		the DLR protocol
0x48	QoS object	Contains mechanisms used to treat traffic streams with	1
		different relative priorities
0xF4	Port object	Contains implemented port types port numbers and	1
		port names
	TCP/IP interface object	Contains all attributes for configuring the TCP/IP	1
0xF5		interface
0xF6	Ethernet link object	Contains connection-specific attributes like	3
		transmission rate, MAC address, or duplex mode

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23h Position sensor	01h Identity
	02h Message
	router
04h Assembly
	F4h
	F5h
	F6h
	Network
	06h Connection manager

The Class Instance Attributes for the position sensor object are provided in the tables below.

See Appendix B on page 53 for an example of how to create an explicit message in

RSLogix 5000 using the position sensor object tables.

Class services of the position sensor object

Instance	Service Name	Description
0x05	Reset	Reboot with all EEProm parameters of the encoder, reboot with the factory
		defaults
		00: reboot Object– read all EEProm parameters
		01: set and save factory defaults and reboot object– read all EEProm parameter
0x0E	Get_Attribute_Single	Returns value of attribute
0x15	Restore	Restore all parameter values from the non-volatile storage, customer defaults
(21dec)
0x16	Save	Save parameters to the non-volatile storage
(22dec)

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Class attributes of the position sensor object

Num	Required/	Access
(dec)	optional	rule	Name	Data type	Description	Default
1	Required	Get	Revision	INT	Object revision no	0x00 02
	(implemented)
2	Implemented	Get	Max instance	INT	Max. instance number of an object	0x00	01
					in this class
3	Implemented	Get	Number of	INT	Number of object instances in this	0x00	01
			instances		class
6	Implemented	Get	Maximum ID	INT	Highest implemented class ID	0x00	64
			number class
			attributes
7	Implemented	Get	Maximum ID	INT	Highest implemented instance	0x00	7A
			number		attribute ID
			instance
			attributes
100	Get	NV (1)	Encoder	ARRAY	aa.bb: major revision	842eaa.bb
			firmware	of bytes	minor revision	dd.mm.yy
			version		dd.mm.yy: day.month.year

(1) Nonvolatile

Instance Services of the position sensor object are automatically populated in the explicit message instruction configuration

Instance services of the position sensor object

Instance	Service name	Description
0x0E	Get_Attribute_Single	Returns value of attribute
0x10	Set_Attribute_Single	Sets value of attribute

1Instance attributes of the position sensor object

Attribute ID	Attribute ID	Access	NV /				Min. / max
(dec)	(hex)	rule (1)	V (2)	Name	Data type	Description	(default)
1	1	Get	V	Number of attributes	INT	Number of supported attributes in this	0x0039
						class
2	2	Get	V	Attribute list	ARRAY	List of supported attributes	–
					of byte
10	A	Get	V	Position value signed	DINT	Current position value (32 Bit)	none
11	B	Get	NV	Position sensor type	INT	Device Type	Min 0x00 01
				(see following table, encoder ID)		0x01: Single-turn absolute encoder	Max 0x00 02
						0x02: Multi-turn absolute encoder	(0x00 02)
12	C	Set	NV	Direction counting toggle, code	BOOL	Definition of direction of incrementing	(0: CW)
				sequence (CS)		counts (10)
						0: CW
						1:CCW
13	D	Set	NV	Commissioning diagnostic control	BOOL	ON: 1 Encoder diagnostics possible	(OFF: 0)
				(encoder position test)		OFF: 0 No diagnostics implemented
14	E	Set	NV	Scaling function control (SFC)	BOOL	ON: 1 calc. value (from 16+42)	(OFF: 0)
						OFF: 0 phys. resolution [steps]
15	F	Set	NV	Position format	ENG	Format of position value	(0x1001)
					UNIT	(e.g., arcsec or steps)
						Engineering unit: 0x1001 (counts)

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	Attribute ID	Attribute ID	Access	NV /				Min. / max
	(dec)	(hex)	rule (1)	V (2)	Name	Data type	Description	(default)
	16	10	Set	NV	Counts per range	DINT	Number of requested steps per	Min 0x00 00 00 01
							revolution.	Max 0x00 04 00 00
								(0x00 04 00 00)
	17	11	Set	NV	Total measuring range	DINT	Total resolution	Min / Max
								0x00 00 00 01 /
								Max. 2^n * Attr.16 (Max.
								2^n * Attr.16)
	18	12	Set	NV	Position measuring increment	DINT	Minimum resolution in steps (is always	(0x00 00 00 01)
							0x00 01)
	19	13	Set	NV	Preset value	DINT	The preset value is set to the current	Min / Max
							position value	0x00 00 00 00 /
								Attr.17 - 1
								(0x00 00 00 00)
	21	15	Get	V	Position status register	BYTE	State of the software limit switch	(0x00)
							Bit 0: Out of range
							Bit 1: Range overflow
							Bit: 2: Range underflow
							Bit 3…7 reserved
	22	16	Set	NV	Position low limit	DINT	Lower limit for position	0x00 00 00 00
	23	17	Set	NV	Position high limit	DINT	Upper limit for position	0x3F FF FF FF
	24	18	Get	V	Velocity value	DINT	Current velocity (32 Bit)	Format (25) und (26)
	25	19	Set	NV	Velocity format	ENG	Format of velocity value	(0x1F0F)
						INT	0x1F04 counts/s
							0x1F0E revs/s
							0x1F0F revs/min
	26	1A	Set	NV	Velocity resolution	DINT	Minimum resolution of velocity value	(0x00 00 00 01)
							(24)
	27	1B	Set	NV	Minimum velocity setpoint	DINT	Minimum velocity set-point for setting	(0x00 00 00 00)
							warning flag (47)
	28	1C	Set	NV	Maximum velocity setpoint	DINT	Maximum velocity set-point for setting	(0x3F FF FF FF)
							warning flag (47)
	29	1D	Get	V	Acceleration value	DINT	Current acceleration (32 Bit)	Format (30) und (31)
	30	1E	Set	NV	Acceleration format	ENG	Format of acceleration value	(0x0810)
						UNIT	0x0810: cps/s
							0x0811: rpm/s
							0x0812: rps/s
	31	1F	Set	NV	Acceleration resolution	DINT	Minimum resolution of acceleration	(0x00 00 00 01)
							value
	32	20	Set	NV	Minimum acceleration setpoint	DINT	Minimum acceleration set-point	(0x00 00 00 00)
	33	21	Set	NV	Maximum acceleration setpoint	DINT	Maximum acceleration set-point	0x3F FF FF FF
	41	29	Get	V	Operating status	BYTE	Operating status encoder
							Bit 0: Direct. 0 (inc.) 1 (dec.)
							Bit 1: Scaling 0 (off) 1 (on)
							Bit: 2…4 Reserved
							Bit: 5: Diag. 0 (off) 1 (on)
							Bit 6…7 manuf. spec.
	42	2A	Get	NV	Physical resolution span (PRS)	DINT	Number of steps per rev	(0x00 04 00 00)
							Basic = 15 bit
							Advanced = 18 bit
							(single-turn part)
	43	2B	Get	NV	Physical resolution	INT	Number of revolutions	(0x00 01) single
					number of spans		(multi-turn part)	(0x10 00) multi
	44	2C	Get	V	Alarms	WORD	Flags for alarms (errors)
	45	2D	Get	NV	Supported alarms	WORD	Information on supported alarms	0x3003
	46	2E	Get	V	Alarm flag	BOOL	Indication of set alarm	0: OK
								1: Alarm error
	47	2F	Get	V	Warnings	WORD	Flags for warnings
	48	30	Get	NV	Supported warnings	WORD	Information on supported warnings	0x673C

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	Attribute ID	Attribute ID	Access	NV /				Min. / max
	(dec)	(hex)	rule (1)	V (2)	Name	Data type	Description	(default)
	49	31	Get	V	Warning flag	BOOL	Indication of set warning	0: OK
								1: Warning Flag
	50	32	Get	NV	Operating time	DINT	Storage of operating time counter	0
							[0,1h], the format of the counter is
							second.
	51	33	Get	NV	Offset value	DINT	Offset value is calculated when using	0x00 00 00 00
							preset function
	100	64	Get	V	Temperature value	INT	Current temperature value	0xF0 60
							-40…100°C or -40…212°F	0x27 10
							Accuracy of the temperature sensor is	(-4000… +10000)
							about +/- 5 °C.
	101	65	Set	NV	Temperature value format	ENG	Format of temperature value	(0x1200)
						UNIT	°C or °F (Fahrenheit)
							0x1200: °C
							0x1201: °F
	102	66	Set	NV	Temperature resolution	DINT	Minimum resolution of temperature	(0x00000001)
							value
							[°C/100] or [(°F)/100]
	103	67	Set	NV	Minimum temperature value	INT	Minimum temperature set-point	0xF0 60
					setpoint		(-40…100°C, -40…212°F)	(-4000)
	104	68	Set	NV	Maximum temperature value	INT	Maximum temperature set-point	0x27 10 (+10000)
					setpoint		(-40…100°C, -40…212°F)	or 0x52D0
								(+21200)
	105	69	Get	V	Fault header	DINT	Flags of encoder sensor errors and	0x00 00 00 00
					(see Sensor error table)		warnings
	106	6A	Set	NV	Slave sign of live	DINT	Flags for encoder functionalities	0x0000500
							(Bit-field):
							Bit 0: Slave sign of live (on/off)
							Bit 1…7: not used
							Bit 8…15: UpdateFactor (1…127)
							Bit 16…31: not used
	107	6B	Get	NV	Encoder motion time	DINT	Storage of the motion time. This counter	0
							is incrementing if the encoder is in
							rotation [sec].
	108	6C	Get	NV	Encoder operating time [second]	DINT	Storage of the operating time. This	0
							counter is incrementing if the encoder is
							powered on [sec].
	109	6D	Get	NV	Max velocity	DINT	Storage of the maximum velocity of the	0
					RA [cnts/ms]		encoder in operational state.
	110	6E	Get	NV	Max acceleration [cnts/(ms)2]	DINT	Storage of the maximum acceleration of	0
							the encoder in operational state.
	111	6F	Get	NV	Max temp [°C/100]	DINT	Storage of the maximum temperature of	2000
							the encoder in operational state
	112	70	Get	NV	Min temp [°C/100]	DINT	Storage of the minimum temperature of	2000
							the encoder in operational state
	113	71	Get	NV	Number of startups	DINT	Storage of the number of startups	0
							(power-on) cycles
	114	72	Get	V	LED current value [μA]	INT	Current LED current [μA]	200…25.000
							Range: 200…25.000	(0)
	115	73	Get	NV	Max current value [μA]	INT	Max. LED current [μA]	1.500
	116	74	Get	NV	Min current value [μA]	INT	Min. LED current [μA]	1.500
	117	75	Get	V	Power supply voltage [mV]	INT	Current supply voltage [mV]	9.500…30.500
					Accuracy is about 1% from the		Range: 9.500…30.500	(24.000)
					measurement value.

(1)You can do a Get of all the Set values, as shown in Appendix B, page 53. It is always good programming practice to do a Get after setting a value to ensure the Set command was successful.

(2)Nonvolatile/volatile

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