Mike's PBX Cookbook

USB-Serial adapters

In Windows... for Mac's, see Mac's and serial TTY's.
Make sure you have installed a driver for your USB-Serial adapter!

Confirming which COM port the USB adapter is associated with:

  1. Access the Windows System Properties by right clicking on 'My Computer' and selecting Properties.
  2. Select the Device Manager from the top left of the System window
  3. Click on the plus + sign next to Ports (COM & LPT)
  4. One of the devices will be the USB-Serial adapter. The COM port number is shown at the end of the line (eg: Belkin USB-to-Serial-Adapter (COM4) )

Assigning a fixed COM port number:

A 'feature' of windows is that the COM port number will change each time the USB device is plugged in, unless it's set in device manager:

  1. In Device Manager, right click on the 'USB-to-Serial Adapter'
  2. Select the Port Settings tab, and click Advanced...'
  3. From the drop down COM Port Number box, select the port the adapter should always use.
  4. Click OK and close remaining windows

The adapter will now always take the port specified when plugged into the same physical USB port on the PC. This allows a consistent COM port number for software to look for, and that the specified port configuration will survive a PC re-boot..