Instruction Manual
3
This will assure safety for maintenance personnel and RIO users. Choose a low impedance earth ground for your cable
system, preferably factory ground.
• A poor earthing and bonding condition affects
electronics equipment (e.g. PLC’s, I/O modules,
communication interfaces, etc.) and by the way the
quality of communication links (RIO, Modbus,
Ethernet, etc.).
• For earthing, avoid long wires, loose contacts,
contacts done on painted surfaces, that don’t insure
a good electrical contact.
Guideline for avoiding Electromagnetic interferences
• The cable system must be dedicated to RIO – no other signals or power can be applied or transmitted on this
network.
• Do not route trunk cable into equipment cabinets or panels. Trunk cable and taps should be mounted away from
cabinets or panels in a separate enclosure.
• Install cable in steel conduit in high noise environments.
• Avoid installation of RIO cables in trays or
conduits that contain AC or DC power cable or power
services; Separate RIO cable from power cable or
power sources; trunk cable runs should avoid panels,
trays, and other enclosures that contain power wires.
Make sure that any RIO cable shall cross power
cable at right angles only.
Note: We recommend that a spacing of 0.3 to
0.35m/kV (12 to 14 in./kV) of power cablings shall be
maintained between the RIO cable installation and
power cables.
Mechanical considerations
• Minimum bending radii specified for the trunk and drop cables shall not be exceeded.
• The physical cable installation must be well supported, and cable pull strength must be considered; some
manufacturers suggest that RG-6 and RG-11 cable be supported at least every 50 ft. Contact the manufacturer to
ensure that you do not exceed the cable strain limit.
Note: If the cable is bent more than the allowable bending radius or if the installation is not adequately supported, you
can easily damage the central conductor, the dielectric, and the cable shield. This damage can cause signal waveform
reflections back into the cable system and distortions due to cable impedance alterations away from 75 Ω. The end result
will be a series of transmission errors or a non-functioning link system.
Environmental conditions
In harsh electromagnetic environment (e.g. with a lot of power converters, powerful speed drives, long and very
disturbing power cables running, motors, welding machines, power contactors, etc.) it is recommended, for
communication networks, to use optical fibre media between different rooms, islands or buildings. The optical fibre
provides electrical isolation between the different islands and avoid electromagnetic coupling regarding disturbing zones.
Surge suppressors are recommended when a cable system is installed outdoors or in any environment where
lightning protection is required. The surge suppressor must be grounded to work properly.
On the same equipotential room, coaxial cables could be used.