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1.2 Network Configuration of DeviceNet
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1.2 Network Configuration of DeviceNet
This section describes the network configuration of the DeviceNet.
1.2.1
Network Configuration
A DeviceNet network configuration consists of a trunk line and drop lines as shown in
Figure 1-3.
(1) Nodes
The DeviceNet nodes shown in Figure 1-3 include slave devices, such as input/
output devices, sensors, and drive units, and a master device such as the DN611,
which exchanges data with the slave devices. One network can have up to 64 nodes
and one master device. There are no restrictions in particular on the physical
arrangements of a master device and slave devices.
Set an identification number (node address) for each of the DeviceNet devices on the
network to identify one node from the others. The node address range is 0 to 63 in
decimals, and all the addresses of the nodes connected to the network must be
different.
(2) Trunk Line
The DeviceNet specifications define a trunk line as the cable connecting the most
distant nodes. Nodes can be directly connected to a trunk line (without drop line).
The length of the trunk line varies depending on the communication rate of the
network. A terminator must be attached to both ends of the trunk line.
(3) Drop Line
All the cables branched from the taps on the trunk line are drop lines. The maximum
length of of drop lines is 6 meters (from a tap to the terminal node) regardless of the
communication rate of the network. (The total length of drop lines varies depending
on the communication rate of the network). A drop line can have one or more nodes
connected to it. Nodes can be arranged on the drop lines in any of the following three
configurations shown in Figure 1-3.
(a) Short drop line configuration from tap/multiport tap
(b) Multidrop configuration on a drop line
(c) Branch configuration on a drop line (no branch configuration of trunk lines)
Figure 1-3 Example of DeviceNet Network Configuration
Node 45
Node 5
Node 0
Node 60
Node 55
Node 50
Node 40
Node 30
Node 35
Node
25
Node
20
Node
15
Node
10
Tap
Terminator
Tap
Multiport tap
Branch configuration
Short drop line configuration
No drop line configuration
Multidrop
configuration
Terminator
Tap
Multiport tap
Trunk line
Drop line