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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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