Siemens SIMATIC NET PROFIBUS manual Electromagnetic Compatibility of LAN Cables

Installing LAN Cables

C.4 Electromagnetic Compatibility of LAN Cables

Electromagnetic Compatibility (EMC)

Electromagnetic compatibility (EMC) includes all questions of electrical, magnetic and electromagnetic immunity and emission.

To avoid external interference affecting electrical systems, these effects must be reduced to a certain level. The measures involved include the design, structure and correct connection of the LAN cable. The components and LAN cables for SIMATIC NET PROFIBUS meet the requirements of the European standards for devices used in an industrial environment. This is documented by the CE marking.

Note

The limit values specified can only be guaranteed if the matched components for SIMATIC NET PROFIBUS are used consistently! The installation instructions in this manual and in the manuals of the networked programmable logic controllers must also be adhered to exactly!

C.4.1 Measures to Counter Interference Voltages

Overview

Measures are often taken to suppress interference voltages when the control system is already in operation and problems occur receiving signals. You can often reduce the investment necessary for such measures (for example special contactors) by remembering the following points when installing your automation system.

These include the following:

SConnecting all inactive metal parts to chassis ground

SShielding devices and cables

SSuitable positioning of devices and cable routing

SSpecial noise suppression measures

PROFIBUS Networks SIMATIC NET	C-7
6GK1970-5CA20-0AA1 Release 2 05/2000