how to assign static COM port number to a device

Question

Hi All

I have an issue with one device ( Pax Technology Terminal ) connected to Win 10 ( NCR Point of Sale ). after unplugging the device and connecting it the COM port number changes and every time we have to change the port number back to the correct port number for this device to work.

Is there way I set this device to only get a certain COM port number every time they unplug and connect it back ?? something like setting defaults for each device type

Answer 1

Hi

Windows manages the COM port number assignments, and a device's COM port number may change after a reboot.

To manually change the COM port number of a device:

1. Open Windows Device Manager > right click the device > Properties
2. Under Port tab > Advanced
3. Change COM port number

Also, according to the experience before, the Windows assign the COM port according VID, PID and serial number.
So with the same device plug in, it should always get same COM port assignment.
But when two devices with same VID, PID and serial number might be treated as same device.
When you plug in them in sequence, Windows can assign different COM port for them.
However, after rebooting the Windows with the two USB devices attached, the COM port assignment should be decided by Windows for the two USB devices with same VID, PID and serial number.

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Answer 2

How can ANY two devices have the same serial numbers ??