From: loschen@binah.cc.brandeis.edu
Subject: Problems connecting with Dynacomm SOLVED!!!
Reply-To: loschen@binah.cc.brandeis.edu
Organization: Brandeis University
Date: Tue, 6 Oct 1992 21:34:19 GMT

I'm happy to report that my problems connecting to the network have been 
solved.  Thanks so much to all who responded; I got quite a few good 
suggestions, which I will summarize here.  While frustrating, this 
experience has taught me some good things to know about how 
communications actually works.

The most frequent suggestion was that some sort of device contention was 
causing the problem.  Thanks to Dick Miller, Greg Cook, Rick McCormack, 
and Harlan Stockman for suggestions in this category.  They pointed out 
that if two devices (e.g., serial card, scanner, or mouse) both used the 
same interrupt, problems could arise.  For example, if a serial mouse is 
on COM3 and IRQ4, it might conflict with my modem on COM1 and the same 
IRQ.  In my case, my mouse was set to IRQ5 to avoid such conflicts, and 
I had no other serial ports, so while I imagine that is indeed the most 
common problem, it wasn't mine this time.

A few people suggested changing settings in Windows.  This seemed 
promising, since my new system was running in 386 enhanced mode, while 
the old system was in standard mode.  None of these turned out to be my 
answer, but they might well help in similar circumstances.  Jeff Bamford 
suggested checking to make sure that Windows had the address of the 
serial port right (it did).  Walter Knopf said to try adjusting the 
device contention switches in the Control Panel.  I did, but with no 
luck.  

The third category of suggestions involved the modem itself.  Scott 
Honaker said to be sure that the modem had DTR, DSR, and CD all set on 
or "high."  My modem isn't adjustable in that way, unfortunately.  
Mahesh Viswanathan had a good suggestion of varying the initial commands 
sent to the modem--the Hayes command set includes an X? command which 
controls how the modem handles connecting.  I tried all the possible 
variants here, but there was no change.

Finally, several people suggested changes either in my program or in 
Dynacomm settings.  Chris Lo suggested unchecking an Auto Baud Detect 
box.  I wasn't able to find such a box, but this was pretty close to 
what turned out to be the answer.  Scott Honaker and John Guerin 
suggested alternative programming strategies, including testing for the 
response the modem returns rather than the actual connect status and 
waiting a specific period of time rather than testing for connect status 
at all.  The suggestion that actually worked came from John Guerin:  he 
said to check the setting of the "carrier detect" switch.  I unchecked 
that box, and all of a sudden, like magic, everything was working again.  
I'm not saying I understand why that made a difference--actually, if 
anyone does know why, I'm still curious.  I know that I did have carrier 
detect switched on before.  Nevertheless, it now works, and I'm very 
pleased.  Thanks again, all of you, for helping out, and my apologies 
if I've inadvertently left out your suggestion.  I hope I'll be 
able to return the favor at some point.

Yours thankfully, Chris Loschen

Newsgroups: comp.dcom.modems
From: gtoal@pizzabox.demon.co.uk (Graham Toal)