User`s manual

Serial Programming Tools
Intellio C320Turbo User's Manual 4-11
#define CTSFlowControlBitOn 0x01
#define RTSFlowControlBitOn 0x02
#define HWFlowControlOn 0x03
struct strioctl ioc;
int setting;
setting = CTSFlowControlbitOn;
ioc.ic_cmd = MHWFLOW;
ioc.ic_timout = 0;
ioc.ic_len = sizeof(int);
ioc.ic_dp = (char *)&setting;
ioctl(moxa_fd, I_STR, &ioc);