Too many COM ports used?

[SteveK]

I recently bought a HAM radio. The radio has a serial port for remote
programming it, rather than entering in hundreds of channels by the radio's
keyboard. My 4 yr PC has serial ports but I intend to get a laptop that
doesn't have one so I bought a box that converts USB to serial so that I can
use the USB port on the computer to connect to the HAM radio.

I was successful using the box at work on my Win2K machine by loading the
drivers that come with the USB converter box. But I am not successful
getting the box to operate at home because my XP machine says that it is
already using COM ports 1-13 and when I look at it in the Device Manager I
see that the USB box is COM 14 when I plug it in. The application that uses
the device only allows me to select from a range of COM1 through COM 12.
I have no idea why my XP machine has COM1 through 13 in use. Can someone
tell me how to trouble-shoot this?

Thanks,
SteveK

 

[Dave Patrick]

You might give this a go.

http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/Portmon.mspx

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

 

[SteveK]

You might give this a go.

http://www.microsoft.com/technet/sysinternals/ProcessesAndThreads/Portmon.mspx

I downloaded Portmon and ran it but I see nothing in the window. Under
Computer I picked Connect Local. I have another serial device (my cell
phone, not the HAM radio) hooked up via a USB/serial cable so that Device
Manager shows it as COM 7 but I don't see any activity in the Portmon window
when I upload or download data.

But looking at the screen capture at the site you recommended I'm not sure
what I will be able to figure out once I do get to the point to see some
activity. I don't anything much special installed as far as I know and I'm
wondering why XP is telling me that COM1-13 are in use.

 

[Dave Patrick]

What operating system tool did you use to determine 13 ports were in use?
Are they listed in Device Manager? From a command prompt the mode command
may be of some use.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

 

[SteveK]

I'm using XP Pro. I go to Device Manager > Ports (COM &LPT) > rc on USB
serial Port (COM14) > Properties > Port Settings > Advanced > then in the
COM Port Number pulldown I see 17 entries with COM1 - COM13 saying "(in
use)" and choices for COM14 - 17.

As for the command prompt inspection I only know of netstat -a which shows
TCP and UDP ports but not COM ports.

STeveK

What operating system tool did you use to determine 13 ports were in use?
Are they listed in Device Manager? From a command prompt the mode command
may be of some use.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

I downloaded Portmon and ran it but I see nothing in the window. Under
Computer I picked Connect Local. I have another serial device (my cell
phone, not the HAM radio) hooked up via a USB/serial cable so that Device
Manager shows it as COM 7 but I don't see any activity in the Portmon
window when I upload or download data.

But looking at the screen capture at the site you recommended I'm not
sure what I will be able to figure out once I do get to the point to see
some activity. I don't anything much special installed as far as I know
and I'm wondering why XP is telling me that COM1-13 are in use.

 

[Dave Patrick]

Also try from a safe mode boot. Failing that I'd get in touch with the
hardware manufacturer or try a different brand. I've seen it before where
one device works while the other one fails.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

 

[SteveK]

Dave, I do appreciate your help but I don't think it's a hardware problem
with the usb2serial box because it works on other machines. Yes, I've seen
problems where some sets of USB connectors on the computer actually have
different current or voltage than other sets and things work when plugged
into the front set of ports but not the back set or vice versa. (most
recently my wife's Mac actually had that problem on her G5 and it was
driving me crazy trying to figure out why her webcam wouldn't work).

But I suspect that it has something to do with how my particular XP box has
installed drivers for the COM ports. If that is the case I'm looking for
guidance from someone or from some web page about how to determine where the
COM ports are being assigned. Why would COM 1-13 be saying they are "in
use" when I don't have much plugged in. I guess this has to do with
installing drivers but how I can I tell which ones are messing things up?

It occurs to me: Here is something that I have not yet mentioned.... I also
have used another serial device, my cell phone, along with a special cable
that goes from the serial port of the cell phone to a USB port, along with
the driver software that I installed for that. And that works fine and
assigns itself to COM7 when I plug it in. I've also installed it on my work
computer where the HAM radio's USB2serial box works fine with no COM ports
not available. Oh well.

Also try from a safe mode boot. Failing that I'd get in touch with the
hardware manufacturer or try a different brand. I've seen it before where
one device works while the other one fails.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

I'm using XP Pro. I go to Device Manager > Ports (COM &LPT) > rc on USB
serial Port (COM14) > Properties > Port Settings > Advanced > then in the
COM Port Number pulldown I see 17 entries with COM1 - COM13 saying "(in
use)" and choices for COM14 - 17.

As for the command prompt inspection I only know of netstat -a which
shows TCP and UDP ports but not COM ports.

STeveK

 

[Dave Patrick]

This might be a count against the usb2serial device.

--

Regards,

Dave Patrick ....Please no email replies - reply in newsgroup.
Microsoft Certified Professional
Microsoft MVP [Windows]
http://www.microsoft.com/protect

:

It occurs to me: Here is something that I have not yet mentioned.... I
also have used another serial device, my cell phone, along with a special
cable that goes from the serial port of the cell phone to a USB port,
along with the driver software that I installed for that. And that works
fine and assigns itself to COM7 when I plug it in. I've also installed it
on my work computer where the HAM radio's USB2serial box works fine with
no COM ports not available. Oh well.

<snip>

 

[C.Joseph Drayton]

I recently bought a HAM radio. The radio has a serial port for remote
programming it, rather than entering in hundreds of channels by the radio's
keyboard. My 4 yr PC has serial ports but I intend to get a laptop that
doesn't have one so I bought a box that converts USB to serial so that I can
use the USB port on the computer to connect to the HAM radio.

I was successful using the box at work on my Win2K machine by loading the
drivers that come with the USB converter box. But I am not successful
getting the box to operate at home because my XP machine says that it is
already using COM ports 1-13 and when I look at it in the Device Manager I
see that the USB box is COM 14 when I plug it in. The application that uses
the device only allows me to select from a range of COM1 through COM 12.
I have no idea why my XP machine has COM1 through 13 in use. Can someone
tell me how to trouble-shoot this?

Thanks,
SteveK

Hi SteveK,

Some devices have problems with 'virtual' COMx ports as created by
certain OSes. One of my older Pals was serial and I could get it to
work on a couple of different desktop computers that rather
different OSes. A person at comp.sys.palmtops suggested that it may
be the 'virtual' COMx port was the problem. He suggested I get a
serial PC-Card. I bought one and the problem was solved. Over a
couple of years I used that card in various laptops and never had a
problem with any serial device. I used it for things like custom
test equipment, external modems, GPSs and of course the Palm.

As I recall though the card was pretty expensive. I bought it back
in '01 and I think it was about $150. It you plan on hooking up to
other serial devices it may well be worth the investment.

Ciao . . . C.Joseph

"When hope is lost . . . the spirit dies."
-- Lao Tzu

http://www.tlerma.com/

 

[SteveK]

I got it working!!!

It's a bit of story: As mentioned I also have a usb/serial device that is a
cable for input and output to my cell phone and it comes with drivers. I
have found it also frustrating and confusing to use because sometimes I've
had to reinstall the serial to usb cell phone drivers when I plug it in to
my Belkin usb hub. And when I reinstall the drivers it goes through a cycle
of asking me three times to find drivers on the hard drive or load them from
a CD-ROM, loading three different drivers.

Yesterday I unplugged that cell phone cable and rebooted and when I plugged
it back in it asked me to reinstall again, so I did so, installing three
drivers. Then after that I thought I should check in the Device Manager and
see what it showed, and low and behold it had add three more COM entries to
the pulldown list that I have mentioned I see in the Advanced section of
Ports shown when you right click on the driver in the device manager. Now I
was seeing an additional COM15- COM17. So that seems to explain where the
large amount of COM port choices are coming from. They get assigned and put
"in use" each time that Windows asks to install drivers like in the
paragraph above.

So knowing that that's what the COM ports where doing, it gave me the
confidence to start uninstalling the COM ports. I selected COM ports that
said that they are "in use" and it comes up with a warning saying that I am
assigning a com port to one that is already in use and say OK. Then I go to
the entry in the Ports section of the device manager and say Uninstall and
it goes away. Then I do a right click Scan for New Hardware and it puts an
unrecognized USB device entry in the list and I can right click on that and
go through the reassigning process that I mentioned above and delete that,
and keep repeating.

I did this to the point where I had removed enough COM port assignments that
I was down to a number where the port that was assigned was in the range of
ports that the HAM radio could scan for. The HAM app seems to be written to
only be able to recognize between COM 1- COM12. The cell phone app can
recognize whatever number you tell it. So I gave it a number it could
recognize.

Now both my cell phone and HAM radio applications are happy. Whew. I'll
bet this sounds crazy and to someone who really understands the registry and
how COM port drivers are assigned they probably think my brute force way is
absurd, but I DID IT.

STeveK