On 11/8/2014 1:36 PM, Jason Ricles wrote: > Hi, I am trying to make a program in C to communicate with a temperature > sensor over my serial port that uses RS-485 and is a half duplex. I am > however having trouble getting the device into RS-485 mode, is it possible > to use RS-485 mode in Centos 6.5 or does it only support RS-232 mode? standard legacy PC serial ports are strictly RS232C. RS485 is a 120 ohm balanced line specification. What host-side serial port are you using that has RS485 support? re: linux support, I found this: http://retis.sssup.it/~scordino/code/rs485.html which suggests '485 support is pretty thin in Linux. -- john r pierce 37N 122W somewhere on the middle of the left coast