installation and external connection

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 is not properly earthed and floated from the ground level, then grounding communication cable to the chassis will produce the worst communication. If this is the case, use the power ground point rather than the chassis ground.

HOST PC

RS-422/RS-232

RS-232Converter

RS-422

RS-422 Cable

Communication

Wires

Connect ShieldWire Open

Earth Ground

or Chasis Ground or Power Ground

GND

RS-422

RS-422

RS-422

GND

GND

GND

#1

#2

#3

#n

14_ installation and external connection

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Samsung SSA-P400/EXP, SSA-P400T/EXP manual Installation and external connection, EARTH-GROUNDING the Communication Cables