
B-64044EN/01 CONNECTION 1.CONNECTING THE DeviceNet
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Branch line length
The branch line length is the maximum distance between a T-branch
tap on a main line from which a branch line extends and a node to
which a branch line is connected. The branch line length must be 6
m or less.
Another branch line can be branched from a branch line.
Node
Branch length
(Max. 6m)
T-branch tap
Main line
Node B
Node C
Branch
len
th
Node A
T-branch
tap A
T-branch
ta
B
4m
1m
1m
2m
Main line
Between T-branch tap
and node A: 6 m
Between T-branch tap
and node B: 5 m
Between T-branch tap
and node C: 6 m
ll branch lines must
be shorter than 6 m.
Sample calculation
Total branch line length
The total branch line length is the sum of the lengths of all branch
lines. Even when each branch line is shorter than 6 m, the total
branch line length may be exceeded. The total branch line length
varies with the communication rate.
Communication rate Maximum total branch line length
500 K bit/sec 39m
250 K bit/sec 78m
125 K bit/sec 156m
Node D
6m
T-branch
tap C
Node B
Node C
Node A
T-branch
tap A
T-branch
tap B
4m
1m
1m
2m
Between T-branch tap A and T-branch tap B: 4 m
Between T-branch tap B and node A: 2m
Between T-branch tap B and node A: 1m
Between node B and node C: 1m
Between T-branch tap C and node D: 6m
The total branch line len
th is 12 m.
Sample calculation
Terminator
Terminator