38 • The WAGO-I/O-SYSTEM 750Shielding (Screening)WAGO-I/O-SYSTEM 750ETHERNET TCP/IP2.9 Shielding (Screening)2.9.1 GeneralThe shielding of the data and signal conductors reduces electromagneticinterferences thereby increasing the signal quality. Measurement errors, datatransmission errors and even disturbances caused by overvoltage can beavoided.AttentionConstant shielding is absolutely required in order to ensure the technicalspecifications in terms of the measurement accuracy.The data and signal conductors should be separated from all high-voltagecables.The cable shield should be potential. With this, incoming disturbances can beeasily diverted.The shielding should be placed over the entrance of the cabinet or housing inorder to already repel disturbances at the entrance.2.9.2 Bus ConductorsThe shielding of the bus conductor is described in the relevant assemblyguidelines and standards of the bus system.2.9.3 Signal ConductorsBus modules for most analog signals along with many of the interface busmodules include a connection for the shield.NoteFor better shield performance, the shield should have previously been placedover a large area. The WAGO shield connection system is suggested for suchan application.This suggestion is especially applicable when the equipment can have evencurrent or high impulse formed currents running through it (for examplethrough atmospheric end loading).
