Two conductor shielded is preferred for four reasons.

  1. Unlike coaxial cable where the shield is a signal carrier, two conductor signal carriers are enclosed by the shield and not directly exposed to electrical interference.
  2. The twist of the two conductors provides differential cancellation of magnetic interference.
  3. The stripped and tinned end of the two conductors is easier to connect into terminal block panels.
  4. Because the shield is isolated from the signal carriers, more advanced grounding techniques may be applied. Coaxial cables should only be used if BNC or other types of coaxial connectors are required for the installation.