The recommended characteristics of the RS485/Modbus cable are: twisted pair with tinned copper braid shielding. Minimum overlap: 65%. Gauge: AWG 24. Characteristic impedance: 120 ohms. Maximum linear resistance: 100 ohms/km. Maximum capacitance between conductors: 60 pF/m. Maximum capacitance between conductors and shielding: 100 pF/m. Maximum length of network cable: 1300 m.