COM port assignment with USB->Serial adapter?

Discussion in 'Computer Support' started by Charles, Oct 20, 2006.

  1. Charles

    Charles Guest

    I'm trying to use an appliance that connects to an RS232
    serial port on newer PCs without serial ports by using
    a USB->Serial adapter under Windows XP SP2.

    The (older) software which operates the appliance is
    programmed only to connect to a serial port COM1 to COM4,
    but on some PCs the adapter driver installs as a higher
    port, e.g., COM5.

    If I check the advanced properties of that port with a
    view towards changing it, I find that the lower ports
    are all listed as "in use". However there's nothing in
    the Device Manager under COM ports to indicate what is
    using them.

    How can I determine what is using those ports? Would it
    be possible to reassign whatever it is to a higher
    numbered port so as to free up a port in the COM1-4 range?

    Thanks for your help.
     
    Charles, Oct 20, 2006
    #1
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  2. Charles schrieb:
    > I'm trying to use an appliance that connects to an RS232
    > serial port on newer PCs without serial ports by using
    > a USB->Serial adapter under Windows XP SP2.
    >
    > The (older) software which operates the appliance is
    > programmed only to connect to a serial port COM1 to COM4,
    > but on some PCs the adapter driver installs as a higher
    > port, e.g., COM5.
    >
    > If I check the advanced properties of that port with a
    > view towards changing it, I find that the lower ports
    > are all listed as "in use". However there's nothing in
    > the Device Manager under COM ports to indicate what is
    > using them.


    FWIW, just a few quick shots in teh dark, I've not experienced your
    problem:

    the lower four com ports used to use IRQ 3 and IRQ 4; maybe you can find
    which devices claim those or even free them.

    If you have an IR port, that could take up one of the COM ports as well.

    My ISDN driver used to place modem emulations on some COM ports, have a
    look in network properties. Could be a fax modem, too.

    Cheers
    mendel
    --
    Isn't it amazing how you don't know how to do something and then you do?
    -- Bubbly blonde, Overheard in New York, February 04, 2005
     
    Michael Mendelsohn, Oct 20, 2006
    #2
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  3. Charles

    Guest

    Charles <> wrote:

    >
    >I'm trying to use an appliance that connects to an RS232
    >serial port on newer PCs without serial ports by using
    >a USB->Serial adapter under Windows XP SP2.
    >
    >The (older) software which operates the appliance is
    >programmed only to connect to a serial port COM1 to COM4,
    >but on some PCs the adapter driver installs as a higher
    >port, e.g., COM5.
    >
    >If I check the advanced properties of that port with a
    >view towards changing it, I find that the lower ports
    >are all listed as "in use". However there's nothing in
    >the Device Manager under COM ports to indicate what is
    >using them.
    >
    >How can I determine what is using those ports? Would it
    >be possible to reassign whatever it is to a higher
    >numbered port so as to free up a port in the COM1-4 range?


    Go into your bios and disable com ports 1 and 2, they will then be
    available.
    http://www.google.com/search?hl=en&lr=&q=how to enter bios&btnG=Search

    (Com port 1 is also 3 and 2 is 4)

    --
    Line Rider
    http://www.deviantart.com/deviation/40255643/
     
    , Oct 20, 2006
    #3
  4. Charles

    DanR Guest

    Charles wrote:
    > I'm trying to use an appliance that connects to an RS232
    > serial port on newer PCs without serial ports by using
    > a USB->Serial adapter under Windows XP SP2.
    >
    > The (older) software which operates the appliance is
    > programmed only to connect to a serial port COM1 to COM4,
    > but on some PCs the adapter driver installs as a higher
    > port, e.g., COM5.
    >
    > If I check the advanced properties of that port with a
    > view towards changing it, I find that the lower ports
    > are all listed as "in use". However there's nothing in
    > the Device Manager under COM ports to indicate what is
    > using them.
    >
    > How can I determine what is using those ports? Would it
    > be possible to reassign whatever it is to a higher
    > numbered port so as to free up a port in the COM1-4 range?
    >
    > Thanks for your help.


    Try this free utility: ComCheck32 at bottom of this page.
    http://www.addenda-elect.com/software.htm
    Not sure if it pertains to your problem.
     
    DanR, Oct 21, 2006
    #4
  5. Charles

    beenthere Guest

    "DanR" <> wrote in message
    news:vNr_g.14805$...
    > Charles wrote:
    >> I'm trying to use an appliance that connects to an RS232
    >> serial port on newer PCs without serial ports by using
    >> a USB->Serial adapter under Windows XP SP2.
    >>
    >> The (older) software which operates the appliance is
    >> programmed only to connect to a serial port COM1 to COM4,
    >> but on some PCs the adapter driver installs as a higher
    >> port, e.g., COM5.
    >>
    >> If I check the advanced properties of that port with a
    >> view towards changing it, I find that the lower ports
    >> are all listed as "in use". However there's nothing in
    >> the Device Manager under COM ports to indicate what is
    >> using them.
    >>
    >> How can I determine what is using those ports? Would it
    >> be possible to reassign whatever it is to a higher
    >> numbered port so as to free up a port in the COM1-4 range?
    >>
    >> Thanks for your help.

    >
    > Try this free utility: ComCheck32 at bottom of this page.
    > http://www.addenda-elect.com/software.htm
    > Not sure if it pertains to your problem.
    >

    http://www.pcguide.com/opt/opt/resCOM-c.html
    HTH.
     
    beenthere, Oct 21, 2006
    #5
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