How do you remove the "in use" status in a comm port number when the device that uses the comm port number is not connected?
I have used several products (from different manufacturers) of USB to Serial converters. I will call the different brands of converters device A, device B, etc.. and USB A, USB B, etc.. to identify the different USB ports for simplicity.
Here are the steps and results to better illustrate:
DEVICE USB Port Assigned Comm Port Number
1. A A 1
2. A B 2
3. A C 3
4. B A 4
5. B B 5
As we can see, each device occupies a comm port number for each USB port it is connected to (even when it is the same device connected to a different USB port).
Now, the problem is, I have an application which only accepts ports 1-16. I have already used several brands of USB-Serial converters that the ports 1-20 are already occupied. Now, when I connect a new USB-Serial converter, the comm port number assigned is already 20+. I tried to manually change the comm port number through the device manager, but all the lower numbers are already in use. The devices that occupies the lower numbers are not in the device manager since they are not connected (they are already not working).
Is there a way to "release" the comm port numbers from the converts which are not connected?
Let me know if anything isn't clear.
P.S. Same problem on both WinXP and Win7.