FTDI Community

General Category => Discussion - Drivers => Topic started by: ada on August 30, 2021, 02:28:07 PM

Title: How to get stable COM-ports for different USB port in PC in Windows 10?
Post by: ada on August 30, 2021, 02:28:07 PM

Hi,
I am using a device with FT4232 (VID 0403, PID 6011). If I need to plug it into a different USB port on PC, it will allocate new com port number.
I have tested it on 3 PC (four Windows 10). Two PC are good (no new COM port numbers), two computers allocate new com port numbers.

1) PC HP desktop - Windows 10 PRO - FTDI driver version 2.12.28.0 -> updated continuously ->No problem
2) PC HP desktop - Windows 10 PRO - FTDI driver version 2.12.36.4 -> updated continuously -> Every USB port has own COM port numbers
3a) DELL Optiplex 3080 micro - Windows 10- IOT - Enterprise - LTSC - 1809 - created and updated 7.5.2021 and now -> driver version 2.12.28.0 ->No Problem

3b) DELL Optiplex 3080 micro - Windows 10- IOT - Enterprise - LTSC - 1809 - (created 7.5.2021 and updated continuously) driver version 2.12.28.0 - Every USB port has own COM port numbers

On PC 2 and 3b was problem, I tried uninstalling the driver and installing a new one (2.12.36.4). No success.

Could you tell me where is a problem? Why some PC with FTDI device works correctly and some no? Do you have any idea how to fix it or make sure it doesn't happen again.

Thank you.
Radka

Title: Re: How to get stable COM-ports for different USB port in PC in Windows 10?
Post by: FTDI Community on August 30, 2021, 04:21:01 PM

Hi Radka,
How the parts enumerate could change depending on what other devices maybe connected to the system, if the connections were consistent the enumeration could be the same but couldn’t be guaranteed.

With regard to your comment "I tried uninstalling the driver and installing a new one (2.12.36.4). No success."  Do you mean  you had issues installing the 36.4 driver or that it just didn't help in stabilising the enumeration of the connected devices?

Regards
FTDI Community 

Title: Re: How to get stable COM-ports for different USB port in PC in Windows 10?
Post by: ada on August 31, 2021, 07:46:48 AM

The driver installation went fine. The installation did not fix the port enumeration problem.

Title: Re: How to get stable COM-ports for different USB port in PC in Windows 10?
Post by: ada on August 31, 2021, 07:59:56 AM

As you can see, I connected the FTDI devices (COM 4-7 - they are grey). Then I connected the FTDI device to another USB port (same computer) and the device has COM 8-11.

Title: Re: How to get stable COM-ports for different USB port in PC in Windows 10?
Post by: ada on September 21, 2021, 08:25:43 AM

If IgnoreHWSerNum is set in the registers, COM port numbers are enumerated for each USB port.  ::)