c - Which on turns the receiver on and which one turns the receiver off -

c - Which on turns the receiver on and which one turns the receiver off -

i programming half duplex serial port (rs485) in c (only 1 signal can sent on line @ time) , trying figure out how turn receiver off on device when send request device on serial port. found next code not sure 1 turns receiver off , 1 turns receiver on

struct termios options; tcgetattr(fd, &options); if(on) options.c_cflag |= cread; else options.c_cflag &= ~cread;

can help me decipher 1 turns receiver on , 1 turns receiver off?

c gcc serial-port rs485