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3.5 Network Power/Grounding
3
3.5.4
Network grounding
The DeviceNet requires 1-point grounding (Class D grounding exclusive to controllers)
for the network.
Grounding at two or more points can cause grounding loop. Conversely, an ungrounded
network is likely to malfunction due to external noise.
Use a power tap at the point of 1-point grounding. Connect the ground terminal of the
power tap mentioned earlier to the FG terminal of the power unit, then ground it as close
to the physical center of the network as possible by Class D grounding. (Figure 3-15) .
(Install a power tap near the center of the network and ground it).
When two or more power units are used in the network, ground only the power tap
located near the center of the network.
Use a grounding wire (#8AWG) 3 meters long, maximum.
Figure 3-15 How to Install Your Network
FG
V
−
V +
電源供給装置
電源タップ
V
−
V +
設置端子
接地する電源タップ
Power tap
Grounding terminal
Power unit
Power tap grounded
FG
V
−
V +
電源供給装置
電源タップ
V
−
V +
接地端子
接地しない電源タップ
Power tap
Grounding terminal
Power unit
Power tap not grounded
