Subj : Re: COM  Ring Indicator
To   : borland.public.cpp.borlandcpp
From : Bob Gonder
Date : Sat Jul 16 2005 09:13 pm

Jack Sawatzky wrote:

>Should this work with  GetCommModemStatus()  alone,   or is it necessary
>to use the  WaitCommEvent()?    I wanted to pole the status at regular
>intervals, rather than waiting for a signal change.

I think it would depend on how often you poll.
In the world before MS, that signal would bounce around several times
per ring. (Tracking the A/C ring voltage.)
It should be simple enough to setup a thread that just waits and then
sets a global variable for your poller to find, then goes back to
waiting.

To test out your theory, set your poll to run over 1,000 polls per
second, and have it update the screen with the result (turn something
on/off depending on ring status), then call in and see if the ring
toggles it

.