Earth-Grounding The Communication Cables - Samsung SSA-R2010 User Manual

installation and external connection

EARTH-GROUNDING THE COMMUNICATION CABLES

It is recommended 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, 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 does not lie in connecting either end of the shield wire to the
grounding system; This will cause a current fl ow through the shield wire when the voltage level of both ends of the
shield wire is not equal and this current fl ow 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 fl oated from the ground level, then
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.
RS-232
HOST PC
Earth Ground
or Chasis Ground
or Power Ground
12_
installation and external connection
RS-485/RS-232
Communication
Converter
Wires
RS-485
GND GND
Connect ShieldWire Open
RS-485 RS-485
GND GND