Allen-Bradley ControlLogix DeviceNet 1756-DNB Instruction sheet

Configuration
Manual
DeviceNet
Communication
Module
(Cat. No. 1756-DNB)
Allen-Bradley
Allen-Bradley Drives

Because of the variety of uses for the products described in this
publication, those responsible for the application and use of this
control equipment must satisfy themselves that all necessary steps
have been taken to assure that each application and use meets all
performance and safety requirements, including any applicable laws,
regulations, codes and standards.
The illustrations, charts, sample programs and layout examples
shown in this guide are intended solely for example. Since there are
many variables and requirements associated with any particular
installation, Allen-Bradley does not assume responsibility or liability
(to include intellectual property liability) for actual use based upon
the examples shown in this publication.
Allen-Bradley publication SGI-1.1, “Safety Guidelines For The
Application, Installation and Maintenance of Solid State Control”
(available from your local Allen-Bradley office) describes some
important differences between solid-state equipment and
electromechanical devices which should be taken into consideration
when applying products such as those described in this publication.
Reproduction of the contents of this copyrighted publication, in
whole or in part, without written permission of Allen-Bradley
Company, Inc., is prohibited.
Throughout this manual we make notes to alert you to possible
injury to people or damage to equipment under specific
circumstances.
!ATTENTION: Identifies information about practices
or circumstances that can lead to personal injury or
death, property damage, or economic loss.
Attention helps you:
•Identify a hazard.
•Avoid the hazard.
•Recognize the consequences.
Important: Identifies information that is especially important for
successful application and understanding of the product.
Important: We recommend that you frequently back up your
application programs on an appropriate storage medium
to avoid possible data loss.
PLC-5, DeviceNetManager, FLEX I/O, and RediSTATION are trademarks of Rockwell Automation.
DeviceNet is a trademark of Open DeviceNet Vendor Association (O.D.V.A.).
Windows is a trademark of Microsoft Corp.
Microsoft is a registered trademark of Microsoft Corp.
IBM is a registered trademark of International Business Machines, Incorporated.
All other brand and product names are trademarks or registered trademarks of their respective companies.
Important
Use
r
Information

Preface
Publication 1756–6.5.15 – July 1998

Use this manual to help you understand how:
•the 1756–DNB communicaton module communicates with the
Logix 5550 processor
•to map I/O data using DeviceNet Manager software
•to configure your 1756-DNB communication module
Use this chapter before
you begin configuring
your communication
module.
Chapter 1
Chapter 2 Chapter 3
Appendix A Appendix B
Use this chapter
to plan your
configuration.
Use this chapter
to configure the
communication
module by using
DeviceNet Manager
software.
Use this appendix
for help with
troubleshooting. Use this appendix
to see a scan list
example.
We assume that you:
•are developing a DeviceNet network using a ControlLogix
chassis in conjunction with a 1756-DNB communication module
•know each of your device’s I/O parameters and requirements
•are proficient with DeviceNet Manager software
•are familiar with the MicrosoftWindowsenvironment
What’
s
in
T
hi
s
Manual
?
Audi
e
nc
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Publication 1756–6.5.15 – July 1998
The following conventions appear throughout this manual to guide
you through the information and concepts.
Important: Your screens may appear slightly different than the ones
depicted in this manual if you are running DeviceNet
Manager software on a platform other than Windows
NT, version 4.0.
This is a definition
box. When a word
is bold within the
text of a paragraph,
a definition box will
appear in the left
margin to further
define the term.
The “MORE” icon is placed beside any paragraph that references
sources of additional information outside of this document.
A definition box defines terms that may be unfamiliar to you.
Screen captures are pictures of the software’s actual screens.
The names of screen buttons and fields are often bolded in the
text of a procedure.
Screen Summary The screen-summary arrow points to a table that summarizes
each button and field of the corresponding screen capture.
The optional-step arrow points to a step that is not required for
scanner configuration. It may be a stand-alone feature or may be
dependent upon a set list of criteria.
Optional Step
1Step numbers appear on the screen captures by the
corresponding buttons or fields discussed in the procedure text.
Title Publication Number
DeviceNet Manager Software User Manual 1787-6.5.3
ControlLogix DeviceNet Scanner Module
Installation Instructions 1756–5.66
DeviceNet Cable Planning and Installation Manual DN-6.7.2
Installation
Instructions
DeviceNet
Scanner
(1756–DNB)
DeviceNet
Manager
Software
(Version
3.0)
(1787-MGR)
User
Manual
Conv
e
ntion
s
R
e
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s

P–3
Publication 1756–6.5.15 – July 1998
This term Means
Change of State The communication module can send and receive data with slave
devices that have the change of state feature. Data is sent
whenever a data change occurs or at a user-configurable heartbeat
rate.
Communication
Module This refers to the 1756–DNB communication module.
Cyclic The communication module can send and receive data with slave
devices that have the cyclic feature. Data is only sent at a
user-configurable rate.
Dual Mode The communication module is in dual mode when it serves as a
master to one or more slaves and as a slave to another master
simultaneously.
EDS An electronic data sheet is a vendor-supplied template that dictates
how information is displayed as well as what is an appropriate
entry (value).
Explicit Messaging This messaging protocol states the meaning of the message.
The Explicit Message protocol commands the performance of a
particular task and returns the results of the task performance to
the requestor.
Heartbeat Rate The heartbeat rate is associated with producing data once every
EPR (Expected Packet Rate) duration. You may have four EPRs
before you time out. This only applies to change of state and cyclic
messaging.
Host Platform The computer that hosts the 1756–DNB communication module.
I/O I/O is an abbreviation for “input and output.”
Input Data This data is produced by a DeviceNet device and collected by the
communication module and made available for a host platform to
read.
Output Data This data is produced by a host platform that is written to the
communication module’s memory. This data is sent by the
communication module to DeviceNet devices.
MAC ID A MAC ID is the network address of a DeviceNet node.
Network This is a DeviceNet network or DeviceNet Manager software
representation of a network.
Node A node is the hardware that has a single address on the network
(also referred to as device).
Offline This is when the communication adapter is not able to
communicate on the network.
Online This is when the communication adapter is configured and enabled
to communicate on the network.
PC This is an abbreviation for an IBMcompatible personal-computer.
Poll This is a type of input/output-data communication. A poll message
solicits a response from a single, specified device on the network
(a point-to-point transfer of data).
Record This is a node address and channel-specific memory assigned in
the communication module’s non-volatile storage for a node in the
scan list.
Rx This is an abbreviation for “receive”.
Slave Mode The communication is in slave mode when it serves as a slave to
another master.
Strobe This is a type of input/output-data communication. A strobe
message solicits a response from each strobed device (a multicast
transfer). It is a 64-bit message that contains one bit for each
device on the network.
Tx This is an abbreviation for “transmit”.
Te
rminolog
y
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At Rockwell Automation, customer service means experienced
representatives at Customer Support Centers in key cities
throughout the world for sales, service, and support.
Our value-added services include:
Technical Support
•SupportPlus programs
•telephone support and 24-hour emergency hotline
•software and documentation updates
•technical subscription services
Engineering and Field Services
•application engineering assistance
•integration and start-up assistance
•field service
•maintenance support
Technical Training
•lecture and lab courses
•self-paced computer and video-based training
•job aids and workstations
•training needs analysis
DeviceNet courses Designing a DeviceNet Network (course no.
CCP160) and Configuring a DeviceNet Network (course no.
CCP161) are currently offered. Contact your local authorized
Allen-Bradley distributor or sales/support office for
more information.
Repair and Exchange Services
•your only “authorized” source
•current revisions and enhancements
•worldwide exchange inventory
•local support
S
upport
Se
rvic
es

Chapter 1
What’s in This Chapter? 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Y
ou Need to Know 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Beginning the Process 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PlanningExamples 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About This Example 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Part
I – Photoelectric Sensor Mapping Input Data 1–3. . . . . . . . . . . .
Part
II – RediST A TION Operator Interface Mapping Input Data 1–4. .
Part
III – RediST A TION Operator Interface Mapping Output Data 1–5.
What’s Next? 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2
What’s in This Chapter? 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Y
ou Need to Know 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Y
our Scanner Does 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Communicating
with Y our Devices 2–3. . . . . . . . . . . . . . . . . . . . . .
What
Communication Module Data T ables Are and What They Do 2–4. .
Scanner
Configuration T able (SCT) 2–4. . . . . . . . . . . . . . . . . . . . . .
Scan
List T able (SL T) 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DeviceNet
Manager Software as a Configuration T ool 2–5. . . . . . . . . . .
1756–DNB
Configuration Screen-Map 2–6. . . . . . . . . . . . . . . . . . . .
What’s Next? 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 3
What’s in This Chapter 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What Y
ou Need to Know 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Beginning
the Configuration Process 3–1. . . . . . . . . . . . . . . . . . . . . . .
Online
and Of fline Configuration 3–2. . . . . . . . . . . . . . . . . . . . . . . .
ConfiguringY
our 1756–DNB Communication Module 3–2. . . . . . . . . . .
Accessing
the Module Configuration Screen 3–3. . . . . . . . . . . . . . .
Setting
the Module’ s Operational Parameters 3–4. . . . . . . . . . . . . . .
Assigning Names From the Project 3–6. . . . . . . . . . . . . . . . . . . . . .
Accessing
the Scan List Editor Screen 3–7. . . . . . . . . . . . . . . . . . . .
Entering
the Scan List Editor Screen Through a Project 3–7. . . . . .
Entering
the Scan List Editor Screen Through Network Who 3–7. .
Using
the Scan List Editor Screen 3–8. . . . . . . . . . . . . . . . . . . . . . . . .
Scan
List Editor Functions 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing Devices from the Scan List 3–9. . . . . . . . . . . . . . . . . . . .
Viewing
Device Information in the Scan List 3–9. . . . . . . . . . . . . . . .
Adding
Devices to the Scan List from the Scan List Editor Screen 3–11
Configuring a Device in the Scan List 3–13. . . . . . . . . . . . . . . . . . . .

Planning Your Configuration
Before You Begin
Configuring Through
DeviceNet Manager Software
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Table of Contentstoc–ii
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Using the Slave Mode Function 3–14. . . . . . . . . . . . . . . . . . . . . . . . .
Determining
Data-Mapping Preferences with Auto Map 3–15. . . . . . . .
About
the Data T able Map 3–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using
the Data T able Map for Custom Editing 3–17. . . . . . . . . . . . . . .
Mapping Specific Bits to Specific Device Memory Locations 3–19. . . .
About Y
our Files 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What’s Next? 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
If You Encounter Error Messages 3–21. . . . . . . . . . . . . . . . . . . . . . .
Appendix A
What’s in This Appendix? A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B
What’s in This Appendix? B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Understanding a Scan List Example B–2. . . . . . . . . . . . . . . . . . . . . . .
Photoelectric
Sensor Input Mapping Scheme Example B–3. . . . . . . .
Node
Address 1 Input Data B–4. . . . . . . . . . . . . . . . . . . . . . . . . .
Node
Address 2 Input Data B–4. . . . . . . . . . . . . . . . . . . . . . . . . .
Node
Address 3 Input Data B–5. . . . . . . . . . . . . . . . . . . . . . . . . .
Node
Address 4 Input Data B–5. . . . . . . . . . . . . . . . . . . . . . . . . .
RediSTATION
Operator Interface Input Mapping Scheme Example B–6
RediSTA
TION Operator Interface Output Mapping Scheme Example . . .
B–7
Node
Address 5 Input and Output Data B–8. . . . . . . . . . . . . . . . .
FLEX
I/O Module Input Mapping Scheme Example B–9. . . . . . . . . .
FLEX
I/O Module Output Mapping Scheme Example B–10. . . . . . . . .
Node
Address 22 Input and Output Data B–11. . . . . . . . . . . . . . . .
Troubleshooting
Scan List Example

Chapter 1
Publication 1756–6.5.15 – July 1998

This chapter introduces questions you should ask before configuring
your 1756–DNB communication module. In addition, it presents an
example DeviceNet network and I/O data mapping scheme.
For information about See page
What you need to know 1–1
Beginning the process 1–1
Planning example 1–2
Mapping input data 1–3
Mapping input data 1–4
Mapping output data 1–5
To map data via your communication module, you must understand:
•your network requirements
•how to map input data
•how to map output data
Planning before configuring your communication module helps
make sure that you can:
•use your memory and bandwidth efficiently
•cater to device-specific needs and requirements
•give priority to critical I/O transfers
•leave room for expansion
A very important question to answer is “what is on your network?”
You should be familiar with each device’s:
•communication requirements
•I/O importance and size
•frequency of message delivery
You should also ask “how might this network appear in the future?”
At this point in your planning, it is advantageous for you to have
some idea of how the network could be expanded. When mapping
your I/O, you have the opportunity to allot room for future I/O. This
can save time and effort in the future.
What’
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What
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to
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now
Be
ginning
th
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1–2 Planning Your Configuration
Publication 1756–6.5.15 – July 1998
The following examples illustrate a data-mapping plan for a
DeviceNet network.
About This Example
This example has the following characteristics:
•a PC host platform
•a 1756–DNB communication module
•a Series 9000 photoelectric sensor (strobed)
•a RediSTATION operator interface (polled)
Important: In the following examples, output is data sent to a
device. Input is data collected from a device.
PC running Windows
NT or Windows 95
containing DeviceNet
Manager software
DeviceNet network
Two input bits from the photoelectric
sensor will be mapped: one status bit and
one data bit.
Two input bits from the RediSTATION
operator interface will be mapped: one bit
for the green start button and one bit for the
red stop button. One output bit for the
operator interface will also be mapped: one
bit for the operator interface’s indicator light
(on/off). Bit 4 of the input byte indicates if
the bulb is missing.
Series 9000 photoelectric sensor RediSTATION operator interface
indicator light
green start button
red stop button
1 byte 1 byte
1 byte
input
output
The photoelectric sensor
produces one byte of input
data in response to the
strobe message.
The RediSTATION
operator interface produces
one byte of input data and
consumes one byte of
output data.
status
bit
data
bit
bit for green button
bit for
red button
bit for
indicator light
Node 1
Node 2
RediStation
operator interface
photoelectric sensor
input
1770–KFD
communciation
module
DD
S
SD
Node 62
1756–DNB in ControlLogix chassis
DEVICENET
01234567
01234567
01234567
Node 15
P
lanning
Ex
ampl
es

1–3Planning Your Configuration
Publication 1756–6.5.15 – July 1998
Part I – Photoelectric Sensor
Mapping Input Data
The photoelectric sensor inputs are mapped to the scanner’s input
data table and then to the host platform’s input data file.
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
Word 2
Word 3
Word 4
Word 5
Host Platform
Input Image Table
D = data bit
S = status bit
usage example: 1D = data bit for photoelectric sensor #1
1S = status bit for photoelectric sensor #1
Photoelectric Sensor Input Bytes
photoelectric sensor node address 1
1D1S
1 byte
1
What’s Happening?
= unused bits
Series 9000 Photoelectric Sensor Inputs
word 1
word 0
2
word 2
word 3
word 4
1756–DNB Communication Module Input Image Table
1D1S
word 5
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
Word 6
Word 7
Word 8
Address Data
word 123
up to
Example: The data bit for photoelectric
sensor #1 (1D) appears at word 1, bit 1
in the input image table of your host platform.
1
2
The status and data bits from the
photoelectric sensor are mapped
into the communication module’s
input data table.
The data table is then
transferred to the host
platform’s input data file.
Important: The communication
module’s only makes the data
available for the host platform to
read. The communication
module’s does not move the
data to the host platform.
Word 0
Word 1
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1–4 Planning Your Configuration
Publication 1756–6.5.15 – July 1998
Part II – RediSTATION Operator Interface
Mapping Input Data
The RediSTATION operator interface’s input byte is mapped to the
communication module’s data table. In the RediSTATION’s byte is a
bit for the:
•red button (on/off)
•green button (on/off)
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
Word 0
Word 1
Word 2
Word 3
Word 4
Word 5
Host Platform
Input Data File
R = bit for red button
G = bit for green button
usage example: 2R = red-button bit for station #2
2G = green-button bit for station #2
word 2
word 1
RediSTATION Input Bytes
start/stop station node address 2
2R2G
1 byte
The bits for the
RediSTATION operator
interface’s red and green
buttons are mapped into the
communication module’s data table.
1
2
What’s Happening?
= unused bits
R
e
di
ST
A
T
I
O
N
Input
s
word 3
word 4
word 5
1756–DNB Communication Module Input Image Table
Address Data
up to
word
123
Example: The green start button from
RediSTATION #2 (2G) appears in the host
platform’s input image-file word 2, bit 1.
1
2The data table is then
transferred to the host
platform’s input data file.
Important: The communication
module only makes the data
available for the host platform to
read. The communication
module does not move the data
to the host platform. word 0
1S 1D
2G 2R

1–5Planning Your Configuration
Publication 1756–6.5.15 – July 1998
Part III – RediSTATION Operator Interface
Mapping Output Data
The RediSTATION operator interface’s output is mapped to the
communication module’s discrete output data table. Within each of
these output bytes is a bit for the indicator light. The output image
table is then transferred from the host application. This example
highlights the poll messages from which the RediSTATION operator
interface receives its output bit.
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
0000 0000 0000 0000
Word 0
Word 1
Word 2
Word 3
Word 4
1756–DNB Output Image Table
L = bit for the station indicator light
usage example: 2L = station indicator-light bit
for RediSTATION #2
RediSTATION Output Bytes
2L
1 byte
The indicator-light bit
for each RediSTATION
operator interface is
mapped to the communication
module’s output image table.
1
2
The output image-table
is then sent out to the operator
interfaces via poll messages
from which each operator
interface receives its
indicator-light bit.
What’s Happening?
= unused bits
Mapping Example Part III
RediSTATION Output
word 1
word 0
word 2
word 3
word 4
2L
Address Data
1756–DNB Communication Module Output Image Table
start/stop station node address 2
Example: RediSTATION operator interface’ s
indicator-light bit (2L) is taken from word 1, bit 0 in
the 1756–DNB Output Image Table.
1
2
up to
word
122
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1–6 Planning Your Configuration
Publication 1756–6.5.15 – July 1998
The next step is to understand how to configure the communication
module and perform I/O data mapping through DeviceNet Manager
software. The next chapter details:
•1756-DNB Module Configuration
•1756–DNB Scan List Editor
•Edit Display Properties
•Edit Device I/O Parameters
•1756–DNB Auto Map
•1756–DNB Data Table Map
•1756–DNB Scan List Editor upload and download
What’
s
N
ex
t
?

Chapter 2
Publication 1756–6.5.15 – July 1998

Read this chapter to understand communication between a host
platform and DeviceNet devices through a 1756–DNB
communication module, the data tables, and the DeviceNet Manager
screens used to configure data tables.
For information on See page
What you need to know 2–1
What your communication module does 2–2
What communication module data tables
are and what they do 2–4
Scanner configuration table (SCT) 2–4
Scan list table (SLT) 2–4
DeviceNet Manager software as a
configuration tool 2–5
1756–DNB communication module
configuration screen map 2–6
What’s next 2–7
Before configuring your communication module, you must
understand:
•the data exchange between a host platform and DeviceNet
devices through the 1756–DNB communication module
•user-configurable communication module data tables
•the role of DeviceNet Manager software
What’
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2–2 Before You Begin
Publication 1756–6.5.15 – July 1998
In a typical configuration, the communication module acts as an
interface between DeviceNet devices and the Logix 5550 controller.
The communication module communicates with DeviceNet devices
over the network to:
•read inputs from a device
•write outputs to a device
•download configuration data
•monitor a device’s operational status
The communication module communicates with the processor in the
form of Input, Output, and Diagnostic Tables.
Information exchanged includes:
•device I/O data
•status information
•configuration data
The following is an example configuration.
DeviceNet network
computer with
DeviceNet Manager
software
RediSTATIONt
operator interface
Flex I/Otrack
1305
drive
DeviceNet devices
1770–KFD
communication
module
ControlLogix chassis with 1756–DNB
and Logix 5550 processor
DEVICENET
What
Y
our
S
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2–3Before You Begin
Publication 1756–6.5.15 – July 1998
Communicating with Your Devices
Your communication module communicates with scanned device via
strobe, poll, change of state, and cyclic messages. It uses these
messages to solicit data from or deliver data to each device. Data
received from the devices, or input data, is organized by the
communication module and made available to your host platform.
Data received from your host platform, or output data, is organized
in the communication module and sent on to your devices.
Important: Throughout this document, input and output are defined
from the host platform’s point-of-view. Output is data
sent from the host platform to a device. Input is data
collected by the host platform from a device.
Important: All data sent and received on a DeviceNet network is in
byte lengths. A device may, for example, produce only
two bits of input information. Nevertheless, since the
minimum data size on a DeviceNet network is one byte,
two bits of information are included in the byte of data
produced by the device. In this case (only two bits of
input information), the upper six bits are insignificant.
1756–DNB Communication Module DeviceNet Devices
X
Y
Z
Input Data Storage
Output Data Storage
C
D
E
B
A1
B
C
D
E
X
Y
Z
Input Data From
DeviceNet Devices
Output Data To
DeviceNet Devices
output from the
host platform
input from the
devices to the
host platform
A2
A1
A2
Bits can be mapped to separate
communication module memory
locations; this is known as map segment-
ing. This concept is illustrated in “byte A.”
Byte
0
1
2
3
4
5
...
A strobe message is a
multicast transfer of data
(which is 64 bits in length)
sent by the communica-
tion module that solicits a
response from each
strobed slave device.
There is one bit for each
of the possible 64 node
addresses. The
devices respond with
their data, which can be
as much as 8 bytes.
A poll message is a
point-to-point transfer of
data (0 to 255 bytes))
sent by the communica-
tion module that solicits a
response from a single
device. The device
responds with its input
data (0 to 255 bytes).
A change of state
message is a point-to-
point transfer of data sent
whenever a data
change occurs or at a
user-configurable
heartbeat rate. This does
not solicit response data,
but may receive an
acknowledge message.
A cyclic message is
sent only at a
user-configurable rate.
Allen-Bradley Drives

2–4 Before You Begin
Publication 1756–6.5.15 – July 1998
To manage the flow of data between your processor and a network’s
devices, the communication module uses the following data tables.
•Communication Module Configuration Table
•Scan List Table
•Device Input Data Table
•Device Output Data Table
•Device Idle Table
•Device Failure Table
You may configure two of these data tables through DeviceNet
Manager software. These tables are stored in the communication
module’s non-volatile memory and used to construct all other data
tables:
•Scanner Configuration Table (SCT)
•Scan List Table (SLT)
Scanner Configuration Table (SCT)
The SCT controls basic information your communication module
needs to function on your DeviceNet network. It tells your
communication module:
•if it can transmit and receive input and output data
•how long it waits after each scan before it scans the devices again
•when to send out its poll messages
Scan List Table (SLT)
The SLT supports I/O updating for each of your devices on the
network. It also makes it possible for your communication module to
make device data available to your processor. The SLT tells your
communication module:
•which devices to scan (node addresses)
•how to scan each device (strobe, poll, change of state, cyclic or
any valid combination)
•how often to scan your devices
•exactly where in each device’s total data to find the desired data
•the size of the input data/output data
•exactly where to map the input or output data for your host
platform to read
What
Communication
Module Data Tables Are
and What They Do

2–5Before You Begin
Publication 1756–6.5.15 – July 1998
DeviceNet Manager software configures the communication
module’s data tables. This software tool connects to the
communication module via the DeviceNet network and an RS-232
interface module (1770-KFD) or PC Card (1784–PCD, –PCID).
User
configured
tables
Data in this table DeviceNet Manager
configuration screen See page
SCT Gbasic operation
parameters
Ginter-scan delay
Gbackground poll ratio
1756–DNB Module
Configuration 3–3
SLT Gdevice-specific
identification data Scan List Editor (SLE) 3–8
Gdata transfer method
Gtransmit/receive data size Edit Device I/O Parameters 3–13
Ginput and output data
source and destination
locations
These values can be
configured automatically
through the Auto Map
function on the SLE or
manually through the Data
Table Map.
3–8 for SLE information
or
3–16 for data table map
information
The interscan
delay is the time
between scans.
It is the time the
communication
module will wait be-
tween the last poll
message and hte
start of the next
scan cycle.
The background
poll ratio sets the
frequency of poll
messages to a
device in relation to
the number of
I/O scans.
For example: if the
ratio is set at 10,
that device will be
polled once every
10 scans.
I/O communication
is the exchange
and transfer of input
and output data.
D
e
vic
e
N
e
t
Manag
e
r
Software as a
Configuration Tool
Allen-Bradley Drives

2–6 Before You Begin
Publication 1756–6.5.15 – July 1998
1756–DNB Configuration Screen-Map
To access the Module Configuration
screen from a Network Who, double
click on the 1756–DNB communication
module icon.
The main dialog screen
can be accessed through
either the Network Who
or Project View.
To access the Scan List Editor,
choose Edit Scan List.
To view/edit your scan list’s data table map,
choose Data Table Map.
To access the Module Configuration
screen from a Project View, double click
on the 1756–DNB communication mod-
ule icon.
To have DeviceNet Manager software
automatically map your device data,
choose Auto Map.
To edit the Scan List Editor display
properties choose Display Filters.
To edit devices’ I/O parameters,
choose Edit I/O Parameters.