Hi to newsgroup
I want to implement an RS485 interface to an microcontroller with the purpose of creating a network of 10 controllers located about 200 mt from a pc . Although everything is clear regarding the interface what is obscure is the protection needed. I've seen schemes using a 100 ohm resistor between grounds and a 2 zeners series connected clamping at 13 volts between each data line and ground . Other suggestions are zenistors and varistors , other suggest optical isolation . Does anybody have experience to suggest a simple solution (it is a cost sensitive application) to protect the devices and data lines from surges ??? . I know you can't protect from all surges but a usual protection is ok.