Due to the current changing of telecommunications networks, with the increase of interference sources and integrated wiring network became more widespread, the hard to avoid some information needs to have a secret or tamper-proof requirements. Therefore, shielded twisted-pair cable use and demand is becoming more and more big.

　　However, because many people understanding of double shielded cable, shielded twisted-pair cable is not thorough, even some people are still not clear is shielded twisted-pair cable and the difference between the shielded cable. As to how to correct installation is shielded twisted-pair cable, grounding specification and so on, are often in doubt.

　　(1) shielding layer of single-end grounding: shielded cable will be at the end of the metal shield grounding directly, not grounding or by protecting the other end.

The single-end grounding, shielding layer of a metal shield grounding layer of induced voltage exists between the induction voltage proportional to the length of the cable, but no potential circulation through the shield. Single side grounding is using the inhibition of electric potential difference for the purpose of electromagnetic interference elimination.

The grounding method is suitable for the length of the short circuit, cable length of the induced voltage cannot exceed safe voltage. The existence of electrostatic induction voltage will affect the stability of the circuit, the signal may sometimes come into being effect of antenna.

　　(2) double side grounding is shielded cable grounding the both ends of the metal shield connection.

Grounding on the shielding layer, double end case, won't produce induced voltage metal shielding layer, but affected by the interference magnetic flux will produce metal shielding layer shielding circulation through, if the potential locations A and B are not equal, will form A lot of potential circulation, circulation can produce offset the signal attenuation effect.

　　Power cable grounding on both sides, the motor side must connect on the driver side PE, PE and ultimately access to the earth bus bar in the chassis.

Signal lines need different conditions, in general analog signals of single-end grounding, grounding, in order to avoid double end earth electric potential of different current impact signal; Digital signals or difference claims double-end grounding, is just too much current could also affect the signal.