User`s manual

DeviceNet (Master) Function
8-2
8
[1] Network names and functions
This section lists the device names and functions used in DeviceNet networks.
A example of network
Termination
resistance
Power
tap
Power supply for
communication
(24 VDC)
Multi-drop
method
Node
T branch
method
Branch line
Trunk
T branch
system
Termination
resistance
Multi-drop
method
Branch line
Node
Multi-drop
method
Node Node
T branch
system
Branch line
Branch
line
Node Node Node
Node
Node
Names Functions
Node
Master and slave nodes are available on the DeviceNet.
Master: Integrates external I/Os from each slave.
Slave: Provides connections for external I/Os.
- Since there are no restrictions in allocating a master and slaves, you can arrange
nodes at any location shown above.
Trunk
Cable with a termination resistance at both ends.
- Normally, the cable connecting the terminals the furthest distance apart will be a
trunk cable.
- Use a five conductor cable (2 signal wires, 2 power wires, 1 shield).
- The trunk length is not always equal to the maximum length of the network.
Branch line
A cable branching off the trunk.
- You can add new branch lines to the trunk
- Use a five conductor cable (2 signal wires, 2 power wires, 1 shield).
Connection
method
There are two methods for connecting nodes: T branch and Multi-drop.
T branch method: Uses T branch taps for up to three separate branch lines.
Multi-drop method: Connects a node directly to a trunk or to a branch line.
- Both the T branch method and the Multi-drop method can be used in the same
network.
Termination
resistance
Install a termination resistance (121 ohms) on both ends of the trunk, in order to
reduce signal reflection and stabilize the communication.
Power supply
for
communication
Communication power should be supplied to the communication connector on each
node through the five conductor cable.
- Use only a power supply dedicated exclusively to communications. Do not share
this power supply with other devices.