IDTECK FINGER007 Series, Руководство по устранению неисправностей

Страница: 6 / 9

2) Grounding System Using Shield Wires
We recommend using proper grounding system on the communication cable. The best method
for grounding system is to put the shield wire of the communication cable to the 1
st
class earth
grounding; however it is not so easy to bring the earth ground to the communication cable and
also the installation cost is raised. There will be three grounding point where you can find during
installation;
1.
Earth Ground
2.
Chassis Ground
3.
Power Ground
The most important point for grounding system is not to connect both ends of shield wires to the
grounding system; in this case there will be a current flow through the shield wire when the
voltage level of both ends of shield wire is not equal and this current flow will create noise and
interfere to communications.
For the good grounding, we recommend to connecting ONLY one end of shield wire of
communication cable to grounding system; If you find earth ground nearby, then connect one
end of shield wire to earth ground; If you do not have earth ground nearby, then find chassis
ground and connect one end of shield wire to chassis ground; If you do not find both earth
ground and chassis ground, then connect one end of shield wire to power ground. (GND of the
product)
Note that if the chassis ground is not properly connected to the earth and floated from the ground
level, then grounding to the chassis ground will give the worst communication; in this case we
recommend to using power ground instead of chassis ground.
Figure: Grounding System