Emerson Process Management ControlWave EFM 3808 - Manual (Page 286)

S1400CW Page 5-2 Section 5 - Wiring Techniques
Figure 5-1 - Field Wired Circuits With & Without A Common Return
5.2.2 Use of Twisted Shielded Pair Wiring (with Overall Insulation)
For all field I/O wiring the use of twisted shielded pairs with overall insulation is highly
recommended. This type of cable provides discrete insulation for each of the wires and an
additional overall insulated covering that provides greater E.M.I. immunity and protection
to the shield as well.