Omron DEVICENET -, Operation Manual

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31
Network Configuration Overview Section 2-1
Multi-drop Method
Communications
Power Supply
Use either of the methods shown below to connect the 24-V DC communica-
tions power supply to the trunk line. Refer to
2-4-7 Wiring the Communica-
tions Power Supply for wiring details.
Note 1. The communications power supply can be connected through a T-branch
Tap only when there is just one communications power supply in the net-
work and the total current consumption is 5 A or less.
2. The communications power supply can be connected through a Power
Supply Tap even if there is more than one communications power supply
in the network or the total current consumption exceeds 5 A.
When grounding the communications power supply to an acceptable ground
(100
Ω
or less), connect the communications power supply’s V- and FG termi-
nals.
If an acceptable ground is not available, connecting the V- and FG terminals
may introduce noise into the network so we recommend against connecting
the terminals.
Use a separate power supply for DeviceNet communications. The power sup-
ply can be shared, however, if noise interference is not generated by the inter-
nal circuit power supply, Sensor power supply, or other source.
Connection pattern Connection method
Or
General-purpose Slaves, Special Slaves,
and Masters Environment-resistive Slaves
Multi-drop connections are not allowed.
Node
Multi-drop
Trunk
line Trunk
line
Node
Multi-drop
Branch
line Branch
line
General-purpose Slave,
Special Slave, or Master
Thick cable, thin cable, or
cable with shielded
connector on one end
With thick cable, a multi-drop
connector must be used.
With thin cable, a COMBICON
connector or multi-drop
connector can be used.
Connecting to a T-branch Tap
(See note 1.)
Connecting to a Power Supply Tap
(See note 2.)
+
−
24 VDC FG
T-branch
Tap
Trunk
line Trunk
line
+
−
24 VDC
S
−
+
FG
Trunk
line
Trunk
line
FG V+ V
−