ESA YT4G Visualyser, Hardware Manual, Page: 169 / 178

Chapter 12
Connection cables
165
Visualyser - Hardware Manual - rev. 1.00
Connection cables
General notes
All terminals communicate with the other appliances by serial
communication.
As serial communications are greatly affected by interference,
top-quality shielded cables must be used in order to limit the
influence of interference to a maximum.
The table below shows the features of the cable that is recom-
mended for use for the serial connection.
Great attention must be paid in the choice and lay-
ing of the cables, especially regarding the serial
connection cable.
In all cases:
Look for the shortest route
Lay disturbed cables separately
Disconnect the power supplies before connecting
or disconnecting the communication cables to pre-
vent any damage to the terminals and/or the
device connected.
Connection of
the cable shield
The correct shielding of the interface cables between the ter-
minals and the devices connected to it, is indispensable in
order to guarantee a serial communication without any type of
external interference, therefore, all cables stated in this
manual must be the shielded type and tank containers must
have a metal or plastic conductive case.
The correct method of connecting the shielding is shown in the
lay-out below.
Features of the serial connection cable
Resistance in direct current Max. 151 Ohm/Km
Capacitive coupling Max. 29pF/m
Shielding > 80% or Total
12.