CD Loss Only on Write???

Article View: comp.windows.ms.programmer

Article #277

Back to comp.windows.ms.programmer Previous Next

#277

From: Kevin P. Kleinfelter
Date: Thu, 09 Apr 1992 18:52

20 lines
1392 bytes

I'm writing a little communications program under Windows 3.0.
It appears that Windows only checks for carrier detect (RLSD) while
writing to a port, and never checks for CD loss when *reading*. My program
sends out a frame, and waits for a frame in reply, and it would be nice
to detect CD loss while I'm waiting for the reply.  (I'd like to avoid
writing 'throw-away' characters to the comm port while reading, just to be
able to detect CD loss.)

In fact, TFM even says
    CE_RLSDTO  Receive-line-signal-detect timeout. RLSD is low for the
               duration specified by RlsdTimeout while trying to 
               transmit a character.
                ^^^^^^
Is this true?  Is it improved under 3.1?  Any proposed work-arounds?

-- 
Kevin Kleinfelter @ DBS, Inc (404) 239-2347   ...gatech!nanovx!msa3b!kevin
Dun&Bradstreet Software, 3445 Peachtree Rd, NE, Atlanta GA 30326-1276
WARNING: I have been advised that email to kevin@msa3b.UUCP may bounce.
It looks like email will have to go via 'gatech' because that is well-known.

Technical Details

Message-ID: <1904@msa3b.UUCP>

Path: arc1-ca.pugleaf.net!sparky!uunet!usc!sol.ctr.columbia.edu!emory!wa4mei!nanovx!msa3b!kevin

Show Full Headers

Complete Article Headers

Path: arc1-ca.pugleaf.net!sparky!uunet!usc!sol.ctr.columbia.edu!emory!wa4mei!nanovx!msa3b!kevin
From: kevin@msa3b.UUCP (Kevin P. Kleinfelter)
Newsgroups: comp.windows.ms.programmer
Subject: CD Loss Only on Write???
Message-ID: <1904@msa3b.UUCP>
Date: 9 Apr 92 18:52:41 GMT
Organization: Dun and Bradstreet Software, Inc., Atlanta, GA
Lines: 20