This is NOT something for the Programmers that the average user needs to concern themself with. Even if you program several different radios, as long as they are the type that you connect to the computer one at the time for programming and they use different cables, you are good to go. RT Systems will make the process easy for you by finding the radio with no extra work on your part. What's described below is for Windows operating systems only.

There are times that multiple radios are connected to the same computer with several of the same programming cable. The radios are usually being controlled from other software with the RT Systems cable for the connection. The problem is caused when RT Systems' tries to "help" with programming by automatically finding the radio to be programmed. With several of the same cable attached, the system does not know which one is connected to which radio and the process fails.


Designed in to the Version 5 (Windows only) programmers is the ability to set a com port for the program to use.

The option ForceSerialPort is available to the Version 5 programmers (Windows only). To use ForceSerialPort

  1. Be sure each programmer is up to date through Help | Check for Updates. Each one is processed separately. Be sure to do them all.
  2. Open Regedit
  3. Go to HKey_Current_User\Software\RTSystems V5\[radio mfg]\[radio designation] (where [radio mfg] and [radio designation] are variables used to indicate the different ones of each you have. Change these as needed for your specific radios.
  4. Expand to Settings
  5. On the right, add new DWORD. Name the DWORD ForceSerialPort and set value to the com port designation of the device (check Device Manager for what has been assigned for each).
  6. Be sure to make the entry in Dec (not Hex). Change this at any time that your system changes the designation for a given radio. Note: This works better if the com port designation is less than 16. Remember, you can use any USB designation even if it is in use as long as you know that the other device is not attached to the computer at the same time.

Now when you do communications | Get or Send data, the program will look to that com port designation for the radio.

If when programming you get "ComX unsupported" error, check the com port designation you have assigned for this programmer and check device manager to be sure the designation has not changed since last you used it (this usually does not happen... but it's computers... anything is possible)

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