How to enable SOFT carrier flag ???????

[Uma Krishnan]

I am working on RS6000 /AIX, version 3.1.5.

I would like to know how to enable soft carrier flag after I open a serial
port for read with no delay. I know I should be doing thru' ioctl() call, but 
I do not know what parameter values to pass. The limited documentation that
I have, does not tell me how (and neither does info explorer).

Please e-mail your responses directly to me, since I do not read these
newsgroups too often.

Thanks in advance,

Uma Krishnan