RS485 has two wire system and four wire system two kinds of wiring, four-wire system can only achieve point-to-point communication mode, is rarely used, the use of two-wire wiring mode, this wiring mode is a bus topology, in the same bus can be connected to a maximum of 32 nodes.
Product Description: Characteristic impedance 120 ohms, conductor is 2*2*24AWG multi-strand tinned electrolytic copper wire stranded, color insulation sheath suitable for installation identification, aluminum foil/polyester with overall shielding, additional independent multi-strand stranded tinned copper wire ground conductor, industrial gray PVC outer sheath, in accordance with UL AWM 2919 document.

Service characteristics
RS-485 communication cable can be twisted pair in general occasions, but in the more demanding environment can be used with a shielded layer of twisted pair cable. When using RS485 communication, for a specific transmission line, the cable length between the host (call test equipment) and the 485 port of the instrument is inversely proportional to the baud rate of data signal transmission; This length is mainly affected by the distortion of the signal and the effect of noise. In theory, the transmission distance of RS485 can reach 1200 meters, but in practical applications, the transmission distance is less than 1200 meters, and the specific length is affected by the surrounding environment.

Scope of application
RS232/RS-485 Communication cable The signal cable is suitable for EIA RS-232/422 communication network, and is a common cable model for communication networks such as building automation, industrial control networks, and power automation.