Shielded cable is a cable that has the ability to resist external electromagnetic interference formed by adding a shielding layer to the transmission cable. The shielding layer of RVVP cables is mostly woven into a mesh of metal wires or made of metal films, with various different methods of single shielding and multiple shielding. Single shielding refers to a single shielding mesh or film that can wrap one or more wires. Multi shielding method refers to multiple shielding nets, with the shielding film located in one cable. The mechanism of shielding is to ground the shielding layer to isolate the induced interference voltage of external wires.