Serial RS485

RS-485 standard supports half-duplex data communication, this means that in order to send and receive data using only two cable channels. The specifications of this standard can support data communications from a number of devices and is also capable of supporting data communication in a distance up to 1200 meters. Connection from each device connected to the RS-485 carried out in parallel, so that connection and release device can be done without disrupting the whole network work.

To adjust the impedance of the cable used to install a resistor whose value is adjusted with the characteristic impedance of the cable (~ 120 Ohm). Communication network topology using the RS-485 data can be viewed at the following picture.

Here datasheet for RS485