Controlling Digi One SP RTS and DTR lines


I am trying to use a Digi One SP to connect some software that is written to access a serial port to communicate with a Lacrosse 2300 Weather station over Ethernet.

The WeatherStation needs to be initialized to communicate with it, and thus it needs DTR set low, and RTS set high before serial data can be sent.

In C, through a serial port, this is effected with:
ioctl(ws2300, TIOCMGET, &portstatus); // get current port status
portstatus &= ~TIOCM_DTR;
portstatus |= TIOCM_RTS;
ioctl(ws2300, TIOCMSET, &portstatus); // set current port status

How do I configure the Digi (and RealPort, under Linux) to pass these signals?

Duane (duanek (at) Chorus (dot) net