USB TO RS232 ..more than one in pc ? how to know which is which ?

[Graham]

USB TO RS232 ..more than one in pc ? how to know which is which ?

If I fit more than 1 usb to rs232 adaptor in the pc .(cable with
plugs) .. how do you tell which comm port is which .....?? is
there some code or serial number in the adaptor that links it to
its 'driver'

is this the device instance id ? so I can set each adaptor to its
own comm port number ?

also I seem to have comm ports 3 to 12 all in use ... as I
have only 3 usb serial devices and one usb to parallel printer
cable installed .and 'no' com port on the mother board ... what
is using the other ports ??
G ?

 

[Patrick Keenan]

USB TO RS232 ..more than one in pc ? how to know which is which ?

If I fit more than 1 usb to rs232 adaptor in the pc .(cable with
plugs) .. how do you tell which comm port is which .....?? is
there some code or serial number in the adaptor that links it to
its 'driver'

is this the device instance id ? so I can set each adaptor to its
own comm port number ?

also I seem to have comm ports 3 to 12 all in use ... as I
have only 3 usb serial devices and one usb to parallel printer
cable installed .and 'no' com port on the mother board ... what
is using the other ports ??
G ?

Yes, you can use more than one USB to serial adapter. I do this
regularly.

I would suggest that you plug them in one at a time, and determine the comm
ports assigned to each as they are installed. It is likely to change if
you connect the device to another USB port. And yes, you can change the
port number that's assigned so it works with whatever software you need to
run.

Connectors for devices such as Blackberries and some Bluetooth devices will
also create commports, so that may be where the other ports are being
created.

HTH
-pk

 

[AlecJames]

USB TO RS232 ..more than one in pc ? how to know which is which ?

If I fit more than 1 usb to rs232 adaptor in the pc .(cable with
plugs) .. how do you tell which comm port is which .....?? is
there some code or serial number in the adaptor that links it to
its 'driver'

is this the device instance id ? so I can set each adaptor to its
own comm port number ?

also I seem to have comm ports 3 to 12 all in use ... as I
have only 3 usb serial devices and one usb to parallel printer
cable installed .and 'no' com port on the mother board ... what
is using the other ports ??
G ?
.

2 suggestions for what might be using the ports -
1) a comm port redirector program that creates virtual com ports for
Ethernet connected com ports. Early versions (v3 I think) of the Lantronix
com port redirector allowed you to reserve "blocks" of com ports e.g 3-10.

2) If you are sure that nothing else is using the ports I've seen a problem
with USB to serial converters where a port gets reserved and you can't get it
back. I never got to the bottom of what caused this but the symptom was that
I had to use increasing higher com port numbers as the lower ones appeared in
use.
I found a work around - after inserting my USB-serial adapter I went to
device manager properties for the device and changed the port number to one
of the incorrectly reserved port numbers (device manager, com & lpt,
<assigned port num>, properties, port settings, advanced). It complained
that the port was in use but let me do it anyway. When I removed the device
the port would be correctly released.

hope it helps
A

 

[Graham]

2 suggestions for what might be using the ports -
1) a comm port redirector program that creates virtual com ports for
Ethernet connected com ports. Early versions (v3 I think) of the Lantronix
com port redirector allowed you to reserve "blocks" of com ports e.g 3-10..

2) If you are sure that nothing else is using the ports I've seen a problem
with USB to serial converters where a port gets reserved and you can't get it
back.  I never got to the bottom of what caused this but the symptom was that
I had to use increasing higher com port numbers as the lower ones appeared in
use.  
I found a work around - after inserting my USB-serial adapter I went to
device manager properties for the device and changed the port number to one
of the incorrectly reserved port numbers (device manager, com & lpt,
<assigned port num>, properties, port settings, advanced).  It complained
that the port was in use but let me do it anyway.  When I removed the device
the port would be correctly released.

hope it helps
A- Hide quoted text -

- Show quoted text -

Tnx ...

Well the harware list only shows 3 serial ports comm 2 , 11 ,
14 ..... comm 2 was the only ''free'' low number com port .. the
list shows upto comm 256 ..novel

If i try and alocate say comm 3 to the driver showing 14 .. it
gives a warning about dual usage and instability ..
none of the listing's show comm port usage other than the 3 usb
adaptors

I need one more comm port in the range 1 > 9 as some of the
older software cannot allocate past 9 ..

the mother board is a new gigabyte with all the latest
drivers ... no comm ports on the board .. hence the usb
adaptors ....the mboard is using the on board lan to link to the
router/web ..... as I cannot list the users of the low comm
ports ..its not possible to realocate them ?

catch 22 ?

G ..