Omron DEVICENET -, Operation Manual

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26
Network Configuration Overview Section 2-1
2-1-3 Network Configuration Restrictions
The following table shows the maximum cable lengths and maximum current
for the various cable type/baud rate combinations.
Definition of the
Maximum Network
Length
The maximum network length is the distance between the two nodes that are
farthest apart or the distance between the terminators, whichever is greater.
(The trunk line length and maximum network length are not always the same.)
Definition of Branch
Line Length
A branch line cannot be longer than 6 m.
The branch line length is the distance from the point in the trunk line where
the original branch was made to the end of the branch.
Cable type Baud rate Max.
network
length
Branch
line
length
Total
branch
line
length
Current
capacity
Thick cable 500 kbps 100 m 6 m max. 39 m 8 A
250 kbps 250 m 78 m
125 kbps 500 m 156 m
Thin cable 500 kbps 100 m 39 m 3 A
250 kbps 100 m 78 m
125 kbps 100 m 156 m
Flat cable 500 kbps 75 m 35 m 5 A
250 kbps 150 m 48 m
125 kbps 265 m 135 m
Termi-
nator
Termi-
nator
Node
Node
Communications
power supply
(24 V DC)
Trunk line
Power
Supply
Tap
Ground the
network at only
one point.
The max. branch line
length (from the trunk line
to the last node) is 6 m.
T-branch made with a T-branch Tap
or T-branch Connector
Node
Node
Node Node Node
Node
Current capacity
of trunk line
Thick cable: 8A
Thin cable: 3 A
Maximum network length: 100 m when baud rate is 500 kbps
(When thick cable is used, the network length can be up to 250 m max.
with a 250 kbps baud rate or 500 m max. with a 125 kbps baud rate.)
Branch line
The maximum network length is the
longer of these two distances.
Communi-
cations
power
supply
Node
Node
Branch
line
Node
Node
Branch
line
Terminal Block
with terminator
T-branch Tap
with terminator