EARTH-GROUNDING THE COMMUNICATION CABLES
We recommend you to use a proper grounding system for the communication cables.
The best grounding method is to earth-ground the shield wire of the communication cable. However, the earth-grounding of the communication cable is not easy at all, and it also causes an increased installation cost. There are three grounding points available for installation:
1.Earth Ground
2.Chassis Ground
3.Power Ground
The most important thing about the earth-grounding lies in connecting neither end of the shield wire to the grounding system simultaneously. This will cause a current flow through the shield wire when the voltage level of both ends of the shield wire is not equal and this current flow will introduce some noise and interference to communications.
It is recommended to connect ONLY one end of the shield wire of the communication cable to the grounding system. If you can locate an earth-grounding point nearby, connect one end of the shield wire to that point. If you could hardly locate an earth grounding point nearby, connect one end of the shield wire to the chassis ground point. If you could locate neither of an earth or chassis grounding point nearby, connect one end of the shield wire to the power ground point (GND). Note that if the chassis ground is not properly connected to the earth and floated from the ground level, grounding to the chassis ground will yield the worst communication performance. If this is the case, use the power ground point rather than the chassis ground.
