Rockwell Automation Publication 1718-IN001A-EN-E - June 2020
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1718 Ex I/O
Potential Equalization and Shielding
Sources of Interference
Electromagnetic fields can interfere with the communication path.
Twisted-pair cables significantly reduce the influence of these interference fields,
particularly when compared to cables with parallel cores. The direction of the
recorded interference field in a twisted-pair cable reverses over short intervals.
This means that the induced noise is practically canceled out, while in parallel
cores the noise is active across the entire area.
A shielding keeps interfering noise away from the communication path.
IMPORTANT
The following section cannot provide the reader with a complete picture
of all requirements in terms of grounding, shielding, and lightning
protection. For more information on these topics, see the technical data
and the applicable standards.
