SportIdent Problems

Problem - Too many COM ports on Windows, SI master unit inaccesible

You may find that you plug an SI unit into the PC and when you try to use it, the PC reports that the COM port number is too high.

In particular SI-Config will only work with COM ports that are numbered up to 16.

Each time that you plug a serial-to-USB converter device into a USB port that it hasn't been plugged into before, Windows allocates a new COM port to it. Even devices that appear to be straight USB devices may actually have a built in serial-to-USB converter and may be contributing to the problem. This includes all SportIdent download units, many 3G and 3G WiFi modems.


You need to clean up the unused COM port entries using Windows Device manager. A couple of tricks are required to make them visible in device manager:

  1. Open the properties window for your computer. There are a number of ways to do this - if you have an icon for "My Computer"or "Computer", right-click and choose Properties from the menu.
  2. Click on "Advanced" or "Advanced System Settings" depending on how you got there.
  3. Click on "Environment Variables"
  4. Add a new variable (if you always use the same user, add it to the user variables). The values required are:
  • Variable name: devmgr_show_nonpresent_devices
  • Variable value: 1
  1. Plug a serial-to-USB device in. If you don't do this then Windows 7 (at least) will not show any COM port details. It doesn't matter for now if the only device you have is the one that Windows spat the dummy on.
  2. Start the device manager - there are a few ways of doing this. If you have an icon for "My Computer"or "Computer", right-click and choose Properties. Then choose Device Manager (if you can see it) or Hardware, then Device Manager.
  3. In Device Manager click View and then "Show Hidden Devices"
  4. There should be a branch of the device tree labelled Ports (COM & LPT) or similar. Open this up and you should be able to see the full glory of your COM port frenzy. Right-click and uninstall anything that you don't want to use. If you have the problem device plugged in, then do that one last.
  5. Good luck