
4.CONNECTION TO PERIPHERAL CONNECTION B-64223EN/01
- 62 -
4.11.4 Grounding the Network
Even if the grounding condition on the machine side is satisfied, the
communication line can pick up noise from the machine, depending
on the machine installation condition and environment, thus resulting
in a communication error. To protect against such noise, the
machine should be separated and insulated from the Ethernet trunk
cable and personal computer. Examples of connection are given
below.
[Large-scale network]
[Small-scale network]
Note 1
PC and backbone cable side
Hub power supply
HUB
Electrically separated by
10BASE-T/100BASE-TX cable
connection
Machine system
STP cable
STP cable
Machine Machine Machine
Note 1 Note 1 Note 1
Personal computer
Note 1
Note 1
Machine
STP cable
Hub power supply
HUB
PC and backbone cable side
Machine system
Electrically separated by
10BASE-T/100BASE-TX cable
connection
Personal computer
NOTE
1 Ground the PC and backbone cable separately from the machine system.
If this is impossible because there is only one grounding point, use separate
grounding wires for the PC/backbone cable and the machine system up to the
grounding point.
The grounding resistance must not be higher than 100 Ω (class 3 grounding).
The grounding wire must not be thinner than the AC power line conductor, and its
cross-sectional area must not smaller than 5.5 mm
2
.
2 There is possibility that noise makes the obstacle of communication even if the
ground is separated using the 10BASE-T/100BASE-TX. In the case of using the
FAST Ethernet board under the worst environment, please separate between the
PC/Trunk line side and machine system side completely using the optical fiber media.