While Sending Cold Loader: Could not open Serial Port

Dear All,

         I'm not a professional programmer. Could you hlep me find solution?


        Dynamic C 8.2 for RCM3000
        At first, can do debugging the projects.
        Later on, got this error,
        While Sending Cold Loader: 
        Could not open Serial Port

        What am I wrong to my DC settings or my project files? 


make sure that serial port which you are using is not engaged with the another port.

its better to use 9.XX version for the rabbit 3000 series modules

I’m using Vista and I had the same problem.

My USB to serail port driver was not installed. I went into my PC’s Control Panel and selected ‘Device Manager’ expanded my USB Ports and Ports and found the USB Serial port. Right clicked on it and had windows search for and install the driver for it. It came up as COM5 so when I updated it in Dynamic C it worked.

Sometimes, the port is opened and improperly closed. Rather than restarting your PC, I have found the following to be useful for this particular problem

  • Close the Dynamic C IDE and any other application that might be using a serial port
  • Right-click on My Computer and select Properties
  • In the System Properties dialog, click on the Hardware tab and then click the Device Manager button
  • In the Device Manager dialog, ensure that the Ports (COM&LPT) branch is expanded (click the + box)
  • Right-click on the port being used (for example, COM1) and select Disable … answer Yes to the dire warnings
  • Again, right-click on the port and select Enable
  • Restart the Dynamic C IDE

May be that com port used by another device. Need to close that COM port, if you open any serial console or hyper terminal,Then it should not give this error.