This is a question and answer site for orienteering technology. Ask away or help out with answers if you can. Please vote for answers and questions that are useful.
The site for asking questions about orienteering technology... so that we only make the same mistakes once...or at least just two or three times.

Please search first to make sure your question has not been asked.

Another DamnSillyBigFootIdea

0 votes
SI-Config reports that the serial port number used by my download unit (or the serial to USB converter) is too high. It won't open it for use as a result. How can I fix this in Windows ?     

Rhet Orical
retagged by

2 Answers

0 votes

Stolen from the Big Foot web-site:

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
0 votes
The developer of Radio Online Control has a utility to do the fix described in the earlier answer - see

The utility only works for SPORTident devices - if you have a 3rd party serial-to-usb device, you will have to use the other method.
edited by