1. Introduction to DeviceNet
Chapter 11
Introduction to DeviceNet

2. DeviceNet Purpose Open network Link low-level devices to PLCs Sensors
Pushbutton stations
Distributed I/O blocks
Intelligent motor started overloads
Variable frequency drives

3. DeviceNet Open Network
Network devices (nodes) can be purchased from many different vendors
Network managed by Open DeviceNet Vendors Association (ODVA)
ODVA.ORG

4. DeviceNet Advantage Save wiring costs
Rather than run power wires separately to each device
Rather than run signal wires from each field device separately back to PLC, I/O module connect devices directly to a network
One cable with four wires
Two power wires
Two signal wires

5. Field Devices More Intelligent
Traditional systems
A photo switch counting pieces as they pass on a conveyer was wired directly into an input module.
Counter programmed on ladder to track parts’ count
Counter done bit triggered output point to control field action

6. DeviceNet Advantage Many DeviceNet devices are intelligent.
Photo switch has counters and timers incorporated into sensor.
PLC does not need to have timer or counter on ladder.
When timer or counter is done, the action is carried out through RSNetWorx for DeviceNet software to trigger field device across the network.

7. DeviceNet Components PLC with DeviceNet scanner
RSNetWorx software for DeviceNet
Trunk line
Drop lines
Nodes
Minimum one power supply
Two 121-ohm ¼-watt termination resistors
Up to 64 nodes

8. DeviceNet Network Example
Cable to open-style
connector on
network PLC scanner
Prox switch
and cable
Stack light
KwikLink cable
Power
supply
Termination
resistor
ArmorBlock
maximum
4 I/O points
Termination
resistor
Insulation
displacement
connector
Open-style connection
for power supply
CompactBlock
I/O module
RightSight
photo sensor

9. Sample of Some DeviceNet Media Components
Thick round
drop line cable
Device port
T-port
KwikLink drop
line cable
KwikLink flat trunk
line cable
KwikLink flat trunk
line cable insulation
displacement connector
DeviceLink

10. DeviceNet Cabling Thick round Thin round KwikLink cable
Special-use cable
Open-style connectors

11. Thick Round Cable Used for trunk line
T-ports used to connect from trunk line to drop lines

12. Thin Round Cable Typically used for drop lines
Can be used for trunk in short networks with low current requirements

13. KwikLink DeviceNet Connection
Insulation displacement
connector
KwikLink flat cable

14. Insulation Displacement Connection
For non-wash down
Typical usage conveyor lines
Mount on inside rail of conveyor
No conduit needed
Easy installation of new nodes
No minimum spacing

15. DevicePort Passive 4- or 8-point taps
Connected to trunk line by drop line
Previous slide showed an 8-point DevicePort
Nodes connected to DevicePort by drop lines

16. T-port Used to connect drop line to trunk line
Drop line connected to DevicePort and then on to multiple nodes
Drop line connected directly to node
Maximum drop line length 20 feet

17. DeviceLink Adapter to interface non-DeviceNet devices to network
2- or 3-wire 24-V sensors
Mechanical limit switches
Any non-DeviceNet device with relay contacts
One required for each non-DeviceNet node

18. Additional Media
Refer to the DeviceNet Media catalog for a complete listing of available products.

19. Maximum Trunk Line Length (1 of 2)
Maximum cable distance between any two nodes
Not necessarily actual length of backbone
Maximum length determined by cable type and baud rate

20. Maximum Trunk Line Length (2 of 2)

21. Trunk Line Calculation One
Node number

22. Example One Left terminating resistor to node 1 is 12 feet.
Drop line node 1 is 2 feet.
Right terminating resistor to node 12 is also 12 feet.
Node 12 drop line is 2 feet.
From node 1 drop line to node 12 drop line is 800 feet.

23. Trunk Line Calculation (1 of 2)
For this example, trunk line length is maximum length of cable between terminating resistors.

24. Trunk Line Calculation (2 of 2)
= 824 feet
Refer to table for maximum baud rate of network.

25. Maximum Trunk Line Length
Trunk line length is over 820 feet so maximum baud rate for this network is 125 K.

26. Trunk Line Calculation Two
Power Supply 1 2 3 4 5 6 7 8 9 10 11 12 13 14
6 ft
2 ft
8 ft
300 ft
20 ft
12 ft
3 ft
Node numbers

27. Example Two Left terminating resistor to node 1 drop line is 20 feet.
Right terminating resistor to node 12 drop line is 2 feet.
Node 12 drop line is 8 feet.
Trunk line from node 12 drop to node 14 drop line is 3 feet.
Node 14 drop line is 12 feet.
Node 1 trunk line to node 14 is 300 feet.

28. Trunk Line Calculation
For this example, trunk line length is maximum length of cable between any two nodes or terminating resistors.
Assume round thick trunk line.
Look at network again.

29. Trunk Line Calculation Two (1 of 2)
Power Supply 1 2 3 4 5 6 7 8 9 10 11 12 13 14
6 ft
2 ft
8 ft
300 ft
20 ft
12 ft
3 ft
For this example, trunk line length is maximum length of cable between any
two nodes or terminating resistors.

30. Trunk Line Calculation Two (2 of 2)
The longest cable distance is between the left terminating resistor and node 14.
For this example, the distance between terminating resistors would not be the correct calculation.
= 332 feet
Refer to table for maximum baud rate of network.

31. Maximum Trunk Line Length (1 of 3)
Trunk line length is over 328 feet so maximum baud rate
for this network is either125 K or 250 k.

32. Maximum Trunk Line Length (2 of 3)
The rule is to go back 20 feet from the termination resistors and see if there is a drop line that is longer.
If a drop is longer, then it must be included in the trunk line calculation.
Remember maximum drop line length is 20 feet.

33. Maximum Trunk Line Length (3 of 3)15 8 4 3 7
20 feet
Terminating resistor and node 00 is 3 feet.
Node 00 and node 1 is 4 feet.
Trunk line to node 7 is 15 feet.
15 foot drop is longer than 3 +4 for trunk.

34. Cumulative Drop Line Length (1 of 2)
Sum of all drop lines
Maximum drop line length to any one node
20 feet
Cumulative drop line length also determines network baud rate

35. Cumulative Drop Line Length (2 of 2)
Text figure 11-30
Cumulative Drop Line Length (2 of 2)

36. Total All Drop Line Lengths (1 of 2)

37. Total All Drop Line Lengths (2 of 2)
Cumulative length is 131 feet.
Nodes 10, 13, and 14 exceed the 20-foot maximum drop to any 1 node.
Shorten up cable.
Cumulative drop line length is now 127 feet.
Refer to the table for maximum baud rate for network.

38. Cumulative Drop Line Length
Cumulative drop line length is 127 feet.

39. Power Calculations Add up total device current
Determine trunk line length
Cable type
How many power supplies and where mounted
Look up tables for power allowed on network
Full calculation method available for additional accuracy

40. Common Problems With DeviceNet Networks (1 of 2)
Improper installation
Trunk line length correct?
Cumulative drop line length correct?
Power supply proper size?
Overdriving network with too much information flow?
Refer to DeviceNet Cable System Planning and Installation Manual from Rockwell Automation Web site.

41. Common Problems With DeviceNet Networks (2 of 2)
Network modification after installation
Trunk line length recalculated?
Cumulative drop line length recalculated?
Power supply recalculated?
Overdriving network with too much information flow?

42. DeviceNet Interface

43. FlexLogix PLC DeviceNet Daughter Card
DeviceNet open-style
cable connection point
Set baud rate
Status LEDs
Set interface
card’s node

44. CompactLogix DeviceNet Scanner
Open-style cable connection
CompactLogix processor
CompactLogix is a member of the ControlLogix family.

45. ControlLogix Modular Interface
1756-DNB
ControlLogix modular chassis interface module
1756-DNB
DeviceNet bridge module
Information
window
Status LEDs
Open-style
network connection

46. Example of Rockwell Automation PLC DeviceNet Interface Modules
SLC 500 DeviceNet scanner
1747-SDN
PLC 5 DeviceNet scanner
1771-SDN

47. Example of General Electric PLC DeviceNet Interface Modules
Series PLCs
DeviceNet master module
IC693DNM200
VersaMax PLC
Remote I/O DeviceNet network interface
IC200DB1001

48. Personal Computer DeviceNet Interface
Computer type determines interface needed.
Notebook uses PCMCIA such as a Rockwell Automation 1784-PCD.
Desktop or industrial computer would require a DeviceNet 1784-expansion card.
Computer with serial port could use Rockwell Automation 1770-KFD interface box.

49. Open-style connector to
1770-KFD Interface
Desktop or notebook
computer with serial port
SLC SDN
Interface
cable plug
Open-style connector to
DeviceNet network
Interface cable
KFD to serial port
interface cable
1770-KFD

50. 1784-PCD Card Open-style connector to DeviceNet network
PCMCIA interface
card 1784-PCD
SLC SDN
Notebook
personal computer
Interface cables

51. Use ControlLogix PLC as a Bridge (1 of 2)
Most popular interface to PLC for upload, download, on-line editing is Ethernet
Ethernet interface card in ControlLogix chassis(1756- ENBT)
A 1756-DNB or DeviceNet bridge module in ControlLogix chassis to communicate with DeviceNet

52. Use ControlLogix PLC as a Bridge (1 of 2)
Use RSLinx Ethernet driver to get to Ethernet interface module
Bridge across ControlLogix backplane to DeviceNet Bridge module (1756-DNB)
Out DNB to DeviceNet network
No separate DeviceNet interface required

53. RSNetWorx Software RSNetworx for DeviceNet software Set up network
Map data flowing on network
Program, monitor, or modify device parameters

54. RSNetWorx for DeviceNet

55. RSNetWorx View of DeviceNet
Network scanner
Drop line
Termination
resistor
Termination
resistor
Node address
Trunk line
Device or node
on network
Power supply not shown in RSNetWorx

56. DeviceNet Scan List RSNetWorx software
Scan List is part of scanner properties.
Any device that is on the network that is to be scanned by the PLC scanner must be in the Scan List.
Network devices are not mapped until placed in the Scan List by programmer.
Auto mapping
Manual mapping

57. DeviceNet PLC Scanner Properties
Scan List tab
ControlLogix
DNB scanner
properties screen
Scan List
Add or remove
single device to
or from Scan List
Add or remove
all devices to
or from Scan List
Electronic
keying
Auto map
devices when
add to scan list

58. Available Devices on Network
When going on-line with a network scanner, like a 1756-DNB, scanner will recognize devices currently present on network.
These devices or nodes will be listed in the Available Devices view.
These devices are not in the scan list at this time.

59. Auto Map Devices When Add to Scan List
Do you want the device(s) to be auto-mapped when added to the scan list?
If Automap is selected, you have no control of how devices are mapped.
If you uncheck Automap, then devices can be manually mapped by the programmer.

60. Electronic Keying
How close does a replacement device have to be to the original when replaced?
Device type
Vendor
Product code
Major revision
Minor revision
Minor revision or higher

61. DeviceNet Data Mapping
ControlLogix

62. ControlLogix 1756-DNB Mapping
Input tab
Scanner
properties
Click here to
unmap a device.
Input devices
in Scan List
Unused processor
memory. Can be
manually mapped later.
Data mapping
for each node
ControlLogix processor
tags or addresses
where data is mapped.

63. DeviceNet Data Mapping
ControlLogix is a 32-bit PLC.
All tags will be either 32 bits wide or a:
Word, called an integer (INT) which is16 bits
Byte, called a short integer (SINT) which is 8 bits
Minimum memory allocation for any DeviceNet device is a SINT.
Node 6 is a bulletin 160 Allen-Bradley Drive.
Drive has two words of data.
Drive status information as single bits
Drive speed feedback represented as 0 to 32767

64. ControlLogix Input Mapping
32 Bits
16 Bits 31 16 15 8 7
Node 3 Series 9000
Photo Electric Sensor
mapping
ControlLogix Tags
Node 6 Drive Input Status word
Node 6 Drives Speed Feedback word
Node 4 Series 9000
Photo Electric Sensor
mapping

65. ControlLogix Processor Data Mapping or Tags (1 of 2)
Node 6 is Bulletin 160, the variable frequency drive
Status bits mapped as upper word of Local:1:I.Data[2].
Drive Speed Feedback word is mapped as the lower word of Local:1:I.Data[3].

66. ControlLogix Processor Data Mapping or Tags (2 of 2)
Node 4 is a Series 9000 Photo Switch mapped as the upper byte of the lower word at Local:1.I.Data[2].
Node 3 is a Series 9000 Photo Switch mapped as the lower byte of the lower word at Local:1.I.Data[2].

67. DeviceNet Data Mapping
SLC 500

68. DeviceNet Data Mapping
SLC 500 and PLC 5 are 16-bit computers.
All data will either be a 16-bit word or one byte.
Minimum memory allocation for any DeviceNet device is a byte.
Node 6 is a Bulletin 160 Allen-Bradley Drive.
Drive has two words of data.
Drive Command information as single bits
Drive Speed Command represented as 0 to 32767

69. SLC 500 Output Data Mapping
1747-SDN
properties view
Output mapping tab
Click here to unmap
selected device
Output devices
in Scan List
SLC 500 Output Status
Table where data is
coming from
Two words or 8
bytes currently
mapped for drive
at node 6

70. SLC 500 Processor Data Mapping
Node 6 is Bulletin 160, the variable frequency drive
Drive Command bits word is mapped as O:1.2.
Drive Speed Command word is mapped as O:1.3.

71. Node 2 Output Mapping
Node 8 is a Rockwell Automation 1792D compact block output module.
This compact block has four outputs.
Output data from SLC 500 mapped to lower byte of O:1.6.
Currently upper byte of O:1.6 is available for another device.

72. DeviceNet Nodes General Properties

73. Right click on device on RSNetWorx screen.
General Properties screen is displayed.
Display I/O data
Display, monitor, or modify devices parameters
View electronic data sheet (EDS file)

74. General Properties EDS tab Parameters tab Identifies this device
Current node address.
Node address can be
changed here.
Device’s
identity
Numbers used
to identify EDS file

75. Device Parameters Monitor a single parameter or all Device Parameters
tab
Icons for uploading
or downloading
to device
Lock identifies
read-only
parameters
Click here to
monitor parameter
Parameter
number
Current value
of parameter

76. Parameter Editing Select parameter to edit Options drop-down box

77. Electronic Data Sheets
EDS Files

78. Electronic Data Sheets
Typically referred to as EDS files
EDS files contain information regarding the personality of the device.
Correct EDS file must reside in the device before it can be a working part of the network.
EDS file must be the same firmware level as the device.

79. If EDS File Is Not Current
Go to manufacturer’s Web site and download correct file.
Go to ODVA.ORG site and download correct file.
EDS file numbers represented in Hex.
Use EDS Wizard to update or register the network device.

80. EDS Wizard Updating a network Device’s EDS file is to
register the file.
Click next to continue.

81. Register EDS File After download, browse for file on you computer.
How many
files to register
EDS file name
represented
in Hex
Click next to
continue
registration.

82. Determine EDS File Name
After downloading EDS file, the file name is represented in Hex.
To determine EDS file to use when registering file:
Must know Hex
Construct file number from RSNetWorx general properties page

83. Convert General Properties Page Device Identity to Hex
[1] = 0001
[6] = 0006
[43] = 002B
[1.004] = 0100

84. Select Correct EDS File

85. Select Correct EDS File