In Windows XP / 2000/ NT Com Ports are actively managed by the Windows operating System. Because TrafMan is a DOS Program conflicts can arise when TrafMan tries to access already busy or non existent ports.

To fix this you must go into TrafMan setup and change the Com Port settings to only scan the Port(s) available So windows does not display an error dialog.

Go to TrafMan Main menu

Setup -> Counter Options ->Com Port Options :

Commonly, Com port 1 or 2 would be used by most workstations, PCs or laptops as it is the actual physical Port located on the machine.

Set Com 1 to “Check” and then 2,3,4 to “Always Off” to try. 

Once set you can go back to the main menu and try communications. If the error message appears, then try another port.

If ALL Ports are in use then you must locate and close the other application that has current control over that same Port.

If you have no Com Port installed or cannot access your Com Port, contact your IT Department for a solution prior to contacting DPT Support.