Omron DEVICENET -, Operation Manual

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Network Configuration Overview Section 2-1
The cables branching from the trunk line are known as branch lines.
DeviceNet cables (Special Thin/Thick Cables and Special Flat Cables) are
used for both the trunk and branch lines in DeviceNet communications. Spe-
cial Thin/Thick Cables include Special Thin Cables and Special Thick Cables.
Note With Environment-resistive Slaves (Slaves with a round connector), special
OMRON cable with a shielded, waterproof connector is used for both the
trunk and branch lines.
Terminating Resistors
(Terminators)
Always connect Terminating Resistors at both ends of the network to reduce
signal reflection and stabilize communications. The cable that stretches from
one terminator to the other is the trunk line. Determine which cable will be the
trunk line based on the network’s configuration.
There are two main kinds of Terminating Resistors available, one for the T-
branch Tap/Power Supply Tap and one for a Terminal Block. There are also
connectors with terminating resistance (male and female) that connect to the
Shielded T-branch Connector used with Environment-resistive Slaves.
Note When using a Terminal-block type Terminating Resistor, a DeviceNet cable
must be used for the cable connecting the Terminating Resistor.
Connection Methods
Two methods can be used to connect DeviceNet nodes: The T-branch method
and the multi-drop method. With the T-branch method, the node is connected
to a branch line created with a T-branch Tap or Shielded T-branch Connector.
Terminator
Terminator
T-branch Taps
All are branch lines.
There is no limit on the number of T-branch Taps.
Only the total length of the branch lines is limited.
Trunk
line
Trunk line