i've tried that too

From: steve (steve_at_nospam.com)
Date: 02/18/05 

Date: Fri, 18 Feb 2005 09:02:22 -0800

i have made a simple app that only opens and closes a port. when i run it
with an exteral modem connected to a real port it works normally. when i
run it connected to the internal modem (virtual?) port, it opens the port
normally and hangs the program when i attempt to close the port. this
occurs on multiple computers of various brands around the office, all with
cheapie internal modems of some kind connected to their own ports, and all
runniing win xp. the internal modem ports do not show up under ports in the
device manager, but under modems, the internal modem is shown as connected
to some com port.

i use the program (modem) to connect with modems in the field. the program
runs normally with an external modem connected to a real port. i can open
and close the port, process AT commands, send and receive data, etc. and
yes, i do hangup at the end of a connection. but the problem can be reduced
to simpler terms: if i just load the program and then click exit the
program hangs without any connection being established. loading the program
involves opening the com port and initializing the modem, and occurs without
any problem. the only difference between the external modem on a real com
port version and the internal modem on its own software or virtual com port,
is that i do not try and close the port with the internal modem because that
seems to hang the program. but if i just leave the port as is(open), the
program hangs anyway when i click exit.

any ideas?

"YYZ" <none@none.com> wrote in message
news:eRVxlAdFFHA.3336@TK2MSFTNGP10.phx.gbl...
> "steve" <steve@nospam.com> wrote in message
> news:OqAkM8cFFHA.2832@TK2MSFTNGP14.phx.gbl...
> > yes, i am opening the port and the application runs as it is supposed to
> > using the internal modem. if i try and close the port in the program,
the
> > program hangs. so i do not close it anywhere. and that is, i think the
>
> I don't have a solid answer for you, but have you tried making a very
small
> app that all it does is open then close the port? I would imagine that
> little app would work fine. If it does, then there is something else that
> your code is doing that makes this difficult.
>
> Start small -- addin all your code little bits at a time until it crashes.
> It probably won't take as long as you think, because I bet you can
identify
> LIKELY culprits and add those back in one at a time.
>
> Matt
>
>

Relevant Pages

  • Re: Fax configuration assistance required
    ... from my DSL modem feeds into one side and the line from my fax modem ... in my bedroom to filter out the noise from the DSL and/or fax connection. ... Firewall and 4 Port Switch is connected to the Modem port on the DSL filter ...
    (microsoft.public.windowsxp.print_fax)
  • network hardware- compatible?
    ... dlink DES-1005D 5 ports switch. ... the broadband connection to sister as a new year present. ... modem has 1 RJ45 port on the back. ...
    (microsoft.public.windowsxp.network_web)
  • Re: Modem-to-Modem connection
    ... You are aware that you can connect two computers via a null modem cable ... COM port into an ANALOG signal for transmission over POTS (Plain Old ... The HAYES COMMAND set includes commands to facilitate POTS, ... Establish the connection and then pass that connection off to another ...
    (comp.dcom.modems)
  • Re: Setting hardware flow control on serial port
    ... configure and check HW flow control. ... In my modem initialization string I ... Turning on hardware flow control on the port is important in getting the modem to work properly and for best performance. ... Using the hardwired device file with hardware flow control, you should be able to communicate with the modem with the kermit ...
    (comp.sys.hp.hpux)
  • Re: Fax configuration assistance required
    ... and a seperate DSL ... split between the external modem which handles the DSL internet connection & ... Firewall and 4 Port Switch is connected to the Modem port on the DSL filter ...
    (microsoft.public.windowsxp.print_fax)