
1.CONNECTING THE DeviceNet CONNECTION B-64044EN/01
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NOTE
When thick-wire cables and thin-wire cables are
mixed:
Thick-wire cables and thin-wire cables can be
mixed for connection between two nodes that are
most distant. In this case, however, the lengths of
the cables must satisfy the following expression.
The maximum network length is shorter as
compared with the case where only thick-wire
cables are used.
In addition, the maximum current capacity of each
cable must not be exceeded.
Communication rate Maximum network length
500 K bit/sec Lthick + Lthin ≤ 100m
250 K bit/sec Lthick + 2.5 × Lthin ≤ 250m
125 K bit/sec Lthick + 5 × Lthin ≤ 500m
Lthick :Length of a thick-wire cable
Lthin :Length of a thin-wire cable
Example)
Node
Node
Node
Branch
length
Node
Terminator
Terminator
T-branch tap
T-branch tap
Maximum network length
1m
5m
40m
25m100m
1m
3m
2m
Power supply for
communication
Communication
rate
Maximum network length Enabled/
Disabled
500 K bit/sec Lthick + Lthin=175 ≤ 100m Disabled
250 K bit/sec Lthick+2.5 × Lthin=125+2.5 × 50=250 ≤ 250m Enabled
125 K bit/sec Lthick + 5 × Lthin=125+5 × 50=375 ≤ 500m Enabled
According to the above calculation, communication at a speed of 250
K bits/sec and 125 K bits/sec is enabled in this case. Even when the
above conditions are satisfied, however, a network cannot be
configured if the maximum allowable current capacity is exceeded.