3.5 Network Power/Grounding
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
3
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.
電源タップ
電源タップ
Power tap
Power tap
V − V +
V − V +
接地端子
設置端子
Grounding terminal
Grounding terminal
V − V +
FG
V − V +
FG
電源供給装置
Power unit
Power unit
電源供給装置
接地する電源タップ
接地しない電源タップ
Power tap grounded
Power tap not grounded
Figure 3-15 How to Install Your Network
43
6F8C0845