Different versions of AIX 3.2.5 respond differently to attempts to
enable flow control (RTS/CTS signals).  This section is an attempt to
compile a list of different approaches.

The most straight forward is:
   chdev -l ttyxx -a rts=yes
   [ Note: ix40410 for AIX 3.2.5 should give you this functionality.  
   PTF U426113 and numerous other superceding ptfs should provide this.]

If carrier signal is high (its connected) you can try
   stty add rts </dev/ttyxx 

There is also a program that I first saw on the 800-IBM-4FAX number,
also found in INFO that will remedy the situation in some cases.  Note
that this code ignores the return code from ioctl (which on my machine
is <0 :)

Some parts © 2009 Advameg, Inc.