PHYSICAL LAYERPHYSICAL LAYER

• Support for up to 64 nodes

• Node removal without severing trunk line and under power.

• Protection from wiring errors. Reverse wiring protection circuitry built into devices.

• Selectable data rates: 125, 250, 500 K baud– Not required to support all– Data rates trade speed for distances

• Trunk line-drop line topology– Branching allowed on drops

• Allows zero node separation

General Physical General Physical CharacteristicsCharacteristics

• Twisted pair, low loss, low delay cable

• Use of sealed or open connectors

• Support of both (opto)isolated and non-isolated devices

• Separate power bus contained in the cable– Support of both network-powered and self-powered devices

• High current capability (thick and flat cable supports up to 8 amps)

• Power taps that allow the connection of several power supplies. NOTE: Power Taps are only needed where power supplies are added to network outside of a sealed enclosure. Most power connections are made inside the main control cabinet using ordinary terminal strips.

General Physical General Physical CharacteristicsCharacteristics

DeviceNet Cable DeviceNet Cable HighliightsHighliights

• 5 Conductors, 1 pair for 24 Volts DC power, 1 pair for CAN communication, 1 Shield

• Maximum current capability for 24 Volts DC in thick and flat cable is 8 amps. However no more than 4 amps is permitted in thick cable per NEC Class 2 requirements. ( North America Only )

• Maximum current capability for 24 Volts DC in thin wire is 3 amps.

+24VDC ( V+ )

+0VDC ( V- )

CAN-H

CAN-L

ShieldBare

Blue

WhiteRed

Black

Zero Drop Short DropsBranching Drop

TopologyTopology

Terminator TerminatorTap

Trunk

Daisy Chain max20 feet

Node Node

Node

Node

Node

Node

NodeNode

Node

Node

Node

Trunk Distance

TrunkLength P/S

Termination ResistorsTermination Resistors

• Termination resistors are 120 or 121 Ohms, 1/4 Watt

• They MUST be placed at each end of the trunk line between white and blue wires.

• There are both open and sealed versions

DeviceNet Physical DeviceNet Physical Media TermsMedia Terms

• “Trunk” and “Drops” are topology terms.– The trunkline is the “backbone” of your network. – Drops serve as physical connection mechanisms

to the trunkline. Drop length up to 20 feet.

• There are 3 types of cables: Thick, Flat, and Thin– Thick & Flat cables are rated for 8 amps of current– Thin cable is rated for 3 amps of current– All types of cable can be used for “Trunk”

Cable Budgets - Thick Cable Budgets - Thick TrunkTrunk

Data Rates 125 Kbaud 250 Kbaud 500 Kbaud

Trunk Distance 500m (1640 ft) 250m (820ft) 100m (328 ft)

Max. Drop Length 20 ft 20 ft 20 ft

Cumulative Drop 512 ft 256 ft 128 ft

Number of nodes 64 64 64

Cable Budgets - Thin Cable Budgets - Thin TrunkTrunk

Data Rates 125 Kbaud 250 Kbaud 500 Kbaud

Trunk Distance 100m (328 ft) 100m (328 ft) 100m (328 ft)

Max. Drop Length 20 ft 20 ft 20 ft

Cumulative Drop 512 ft 256 ft 128 ft

Number of nodes 64 64 64

Cable Budgets - Flat Cable Budgets - Flat TrunkTrunk

Data Rates 125 Kbaud 250 Kbaud 500 Kbaud

Trunk Distance 420m (1378 ft) 200m (656 ft) 75m (246 ft)

Max. Drop Length 20 ft 20 ft 20 ft

Cumulative Drop 512 ft 256 ft 128 ft

Number of nodes 64 64 64

Mini Quick Disconnect18mm

Micro Quick Disconnect12mm

“Terminal Strip”Style Connector

Cable

Connectors SupportedConnectors Supported

• Tee Tap– Keyed left & right

• Trunk line segments– molded minior micro connectors– various lengths

• Drop lines– mini or micro molded

connectors– up to 20ft– mini, micro or pigtail at

sensor

• Field Installable trunk line connectors

– screw type

Sealed T-TapsSealed T-Taps

Insulation Displacement Connector(IDC) Used for KwikLinkFlat Cable

• Requirements– Modular

– Low cost

– Minimal installation labor

– Compact package

– Compatible with existing media

– NEMA 6P and 13, IP 67 enclosure rating

Multi-Port Sealed MediaMulti-Port Sealed Media

Drop

Trunk Trunk

DeviceBox™DevicePort™

Drop

(to Trunk)

Drop

• DevicePort Multiport Tap– micro quick

disconnects– various configurations

• DeviceBox Multiport Tap– cord grip– 2, 4, 8 grips

Typical Sealed-Style Typical Sealed-Style TapsTaps

Multiport Taps

Tee Taps

Trunk line segments -molded mini-connectors

Drop lines - molded connectors - 0 to 6 m (20 ft.) - mini or micro at device

Field Installabletrunk lineconnectors -screw type -crimp type

Trunk

Dropline

Open Style TapsOpen Style Taps

• Zero length drop using 1787-Plug10R with probe cable support

Sealed Control Enclosure

OpenStyleDevice

OpenStyleDevice

OpenStyleDevice

OpenStyleDevice

Thick Cable Description

• Signal pair (#18), blue/white• Power pair (#15), black/red• Foil/braid shield with drain wire(#18)• PVC/nylon insulation on power pair• Industrial temperature range

– Storage: -40o C to +85oC– Operating: -20o C to +60o C @ 8A

• derate linearly to 0A at 80o C

• High flexure capability• Flame resistant, UL Oil Res. II• 0.480 inch diameter

DeviceNet Thick CableDeviceNet Thick Cable

Vinyl Jacket.480” O.D.

Beldfoil Aluminum/Polyester Shield

Polypropylene FillersBlue & White Data Pair

Datalene Insulation

18 AWG. Tinned and StrandedCopper Conductors

15 AWG.Tinned and StrandedCopper Conductors

Red & Black DC Power PairPVC/Nylon Insulation

Stranded Drain WireTinned Copper

18 AWG.

65% CoverageTinned Copper Braid Shield

Thick Cable Belden AB numberGrey PVC 3082A YR-29790Yellow CPE 3083A YR-39659

• Signal pair (#24), blue/white

• Power pair (#22), black/red

• Foil/braid shield with drain wire(#22)

• PVC/nylon insulation on power pair

• Industrial temperature range– Storage: -40o C to +85oC– Operating: -20o C to +70o C @ 1.5A

• derate linearly to 0A at 80o C

• High flexure capability

• Flame resistant, UL Oil Res. II

• 0.270 inch diameter

Thin Cable DescriptionThin Cable Description

DeviceNet Thin CableDeviceNet Thin Cable

Vinyl or CPE Jacket.270” O.D.

Beldfoil Aluminum/Polyester Shield

Polypropylene FillersBlue & White Data Pair

Datalene Insulation

24 AWG. Tinned and StrandedCopper Conductors

22 AWG. Tinned and StrandedCopper Conductors

Red & Black DC Power PairPVC/Nylon Insulation

Stranded Drain WireTinned Copper

22 AWG.

65% CoverageTinned Copper Braid Shield

Overall Mylar Tape

Thin Cable Belden AB numberGrey PVC 3084A YR-29832Yellow CPE 3085A YR-39660

KwikLink4-wire Flat Cable

DeviceNet Flat MediaDeviceNet Flat Media

•• 600V, 8A rating 600V, 8A rating

•• Physical key Physical key

•• Fits in 1” conduit Fits in 1” conduit

+24Vdc

DeviceNet Power, 8 Amps Max.

DeviceNet Cable

0 VdcCAN_H CAN_L

User defined 1

0 Vdc

User defined 2

Auxiliary Power Cable

Output Power, 8 Amps Max.

+24Vdc

•• Works with existing devices Works with existing devices

•• TPE / Santoprene jacket TPE / Santoprene jacket

•• Highly flexible Highly flexible

Media Features

• Single & multiple supply configurations

• High current capability by using multiple power supplies.

• Easy to meet supply specifications. 1787-DNPS by Rockwell Automation is worlds only class 2, DeviceNet certified, 5.25 amp power supply.

• Power supplies should be dedicated to DeviceNet cable power ONLY!!

Power Bus CapabilitiesPower Bus Capabilities

NETWORK GROUNDINGNETWORK GROUNDING• V- ( Black Wire ) and Shield ( Bare Wire ) MUST

be connected to a good earth ground at only one location on a DeviceNet System.

Signal

Signal

Shield

V-

V+

V- V+ 24 VDC Power Supply

.

..

..

Power Tap

powersupply

N33 N64N32 N1

up to 500 m

up to 500 m up to 500 m

Single Supply Single Supply ConfigurationConfiguration

• Characteristics and Advantages– Power supplies can be located anywhere on the network

• Must consider IR losses along cable– Greater current than most comparable networks

• Up to 8 amps (NEC limits to 4 amps)– Power supplies are standard, low cost models

Two Supply Two Supply ConfigurationConfiguration

( Current Boost )( Current Boost )

PowerSupply

N33 N64N32N1

up to 500 m

PowerSupply

• Characteristics and Advantages– Loads shared by supplies so same low cost supplies are used– Substantially more current

• Still 8 amp limit on any branch of the trunk ( NEC limit of 4 Amps)

– Supplies can be located anywhere (consider IR losses)

V+ Power Conductor

V- Power Conductor

24 V PowerSupply

Optional SecondSupply

Topology for Power Topology for Power Along the BusAlong the Bus

Node Node Node

24 V PowerSupply

Node

CAN-H, CAN-L, Shield

Power Utilization of Power Utilization of DevicesDevices

• All devices have a source voltage range of 11 VDC to 25VDC. Some devices will draw more current as the source voltage drops.

• All devices on a DeviceNet network will draw at least 50 mili-amps of current off of the 24VDC network power. This is because all products, regardless of type, at the minimum will have their tranceiver circuitry powered from the network power.

• Some devices are designed to draw all of their power off of the network power through the DeviceNet connection entirely. Examples of these type of products include Series 9000 Photoeyes, DeviceLinks and an all input ArmorBlock.

• Some devices will have their power requirements satisfied by another source of current such as external AC voltage or DC voltage through terminal strips. Examples of these type of products include the DTAMPlus, FlexI/O and the Bulletin 160 drive.

• The last category of products are those with outputs driving AC loads or higher current DC loads. These products will have tranceivers and electronics powered by the DeviceNet network power, but the output circuitry will be powered off of an external connector or terminal strip. A classic example device is an ArmorBlock with 2 or 4 DC outputs. In this case a 3 pin mini connector is provided to connect in a source of 24 VDC to power the output circuitry ONLY.

Common Mode VoltageCommon Mode VoltageWhen current is drawn through the power pair on the DeviceNet trunk line,the length of the cable and current draw becomes important. The thick wire,normally used for trunk line, has a resistance of 0.0045 Ohms/foot. So as thedistance from the DeviceNet power supply connection becomes greater, thepower pair will act as a resistor whose value will be equal to 0.0045multiplied by the Distance From The Power Supply ( In Feet ). At anyparticular point on the power pair the Common Mode Voltage will equal theCurrent being drawn on the power pair at that point times the Resistance ofthe Power Pair. ( V = I X 0.0045 X Distance )

The effect of the Common Mode Voltage is that the V+ line will lowergradually from the 24VDC at the power supply as you move farther down thetrunk line. More importantly the V- wire will gradually raise from the 0VDCvalue at the power supply along the length of the trunk line. On mostnetworks the amount of voltage the V+ lowers and V- raises are equal. Soeven though there may be exactly 24VDC measured at Network PowerSupply, further down the cable the voltage on the V+ and V- wires may onlybe 20VDC. This effect is due to Common Mode Voltage and should thevoltage drop become too large the network will fail to operate properly. Sincethe CAN-H (White Wire) and the CAN-L (Blue Wire) both are referenced tothe V- wire, if the V- line varies more than 4.65 VDC at any two points onthe network the CAN tranceivers will fail to operate properly.

An easy way to measure for Common Mode Voltage problems is to go the the farthest ends of the network and measure between the Red V+ and Black V- wires. This voltage should NEVER be less than 15 Volts.

Typical System Typical System ConnectionsConnections

V+

V-

SHLD

CAN-H

CAN-L

Terminal Strip

+24V

0V

PowerSupply

Earth Ground

Normal Control Enclosure

Trunk Line

Scanner PhoenixConnector

KFD/PCD PhoenixConnector

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