COM Ports

R

Roger Mills

My Dell laptop doesn't have *any* physical COM ports.

I have a USB Fax/Modem which was mapped to COM16 - which I needed to
change in order to make it work with a piece of software which only
recognises low COM numbers.

When I found the modem in Device Manager, and then selected Properties
and Advanced Port Settings, it showed 256 COM ports of which COM3
through COM19 were shown to be "in use".

In use for *WHAT*? Anyone know?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.
 
K

Ken1943

My Dell laptop doesn't have *any* physical COM ports.

I have a USB Fax/Modem which was mapped to COM16 - which I needed to
change in order to make it work with a piece of software which only
recognises low COM numbers.

When I found the modem in Device Manager, and then selected Properties
and Advanced Port Settings, it showed 256 COM ports of which COM3
through COM19 were shown to be "in use".

In use for *WHAT*? Anyone know?
Maybe the Windows 7 built in fax program is got everything taken. You
could go to Control Panel > Programs & Features > Turn windows features
on/off and uninstall the fax program. It's somewhere in the list. If it
doesn't help, you can turn it on again, no problem.


KenW
 
K

Ken1943

My Dell laptop doesn't have *any* physical COM ports.

I have a USB Fax/Modem which was mapped to COM16 - which I needed to
change in order to make it work with a piece of software which only
recognises low COM numbers.

When I found the modem in Device Manager, and then selected Properties
and Advanced Port Settings, it showed 256 COM ports of which COM3
through COM19 were shown to be "in use".

In use for *WHAT*? Anyone know?
Make sure you remove the modem first.


KenW
 
R

Rob

My Dell laptop doesn't have *any* physical COM ports.

I have a USB Fax/Modem which was mapped to COM16 - which I needed to
change in order to make it work with a piece of software which only
recognises low COM numbers.

When I found the modem in Device Manager, and then selected Properties
and Advanced Port Settings, it showed 256 COM ports of which COM3
through COM19 were shown to be "in use".

In use for *WHAT*? Anyone know?
I've not seen that yet in Windows 7, but it was common in XP and
the result of badly designed USB/Serial or BluTooth interface chips
together with a suspected USB enumeration bug in XP.
Plugging anything with one of those chips into more than one USB
port resulted in a new COM port being created, leaving more and
more unused phantom ports listed. In your case I suspect internal
blutooth is the cause.
The fix was rather tedious, but basically involved deleting all
of the COM ports from device manager and rebooting.
If any COM ports were *really* being used by internal devices,
they were automatically recreated.
You could try doing the same thing in 7.
HTH
 
P

Paul

Rob said:
I've not seen that yet in Windows 7, but it was common in XP and
the result of badly designed USB/Serial or BluTooth interface chips
together with a suspected USB enumeration bug in XP.
Plugging anything with one of those chips into more than one USB
port resulted in a new COM port being created, leaving more and
more unused phantom ports listed. In your case I suspect internal
blutooth is the cause.
The fix was rather tedious, but basically involved deleting all
of the COM ports from device manager and rebooting.
If any COM ports were *really* being used by internal devices,
they were automatically recreated.
You could try doing the same thing in 7.
HTH
That can happen, if the USB device doesn't have a serial number.

You can use UVCview to review the USB config data, and check for
a serial number. I have two FTDI based USB to serial adapters,
and they come with serial numbers.

iSerialNumber: 0x03
English (United States) "FTEHLXJX"

Paul
 
J

J. P. Gilliver (John)

Roger Mills said:
My Dell laptop doesn't have *any* physical COM ports.

I have a USB Fax/Modem which was mapped to COM16 - which I needed to
change in order to make it work with a piece of software which only
recognises low COM numbers.

When I found the modem in Device Manager, and then selected Properties
and Advanced Port Settings, it showed 256 COM ports of which COM3
through COM19 were shown to be "in use".

In use for *WHAT*? Anyone know?
No idea, but were you able to use COM 2 or 1 (or possibly 0)?
 
R

Roger Mills

No idea, but were you able to use COM 2 or 1 (or possibly 0)?
Yes, I was able to use COM2 - which worked with the software which
didn't like COM16.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.
 
P

Paul in Houston TX

Rob said:
I've not seen that yet in Windows 7, but it was common in XP and
the result of badly designed USB/Serial or BluTooth interface chips
together with a suspected USB enumeration bug in XP.
Plugging anything with one of those chips into more than one USB
port resulted in a new COM port being created, leaving more and
more unused phantom ports listed. In your case I suspect internal
blutooth is the cause.
The fix was rather tedious, but basically involved deleting all
of the COM ports from device manager and rebooting.
If any COM ports were *really* being used by internal devices,
they were automatically recreated.
You could try doing the same thing in 7.
HTH
That happens with USB on my laptop. I have a few
non-normal usb comm things and Win7 likes to create a new
com port if I plug them into a different usb jack other
than the last one used. I periodically delete them all
and start over. My laptop is often used for industrial work.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top