RS-232 Error Occurs in Port Selection.
If you try to select a port from the Settings menu and you keep getting an error it is usually because of one of two reasons. If you get an error Port already in use, this means that you are trying to open a port that is already being used by another hardware device. In most cases this would be a serial mouse, a modem, PDA sync cradle, or any other device that plugs into a serial port. If you have ever had a device such as a Palm pilot or other PDA attached to your computer via the serial port, you need to make sure that the sync software has been terminated. Simply disconnecting your PDA sync cable from the serial port will not close the connection. You need to set the turn off the sync software as well. (Consult your PDA help for more information.)
If you suspect another serial device is active but are unsure of your computers setting, click on the Start button on the task bar, select Settings then choose Control Panel. In the control panel window, double click on the System icon. In the System Menu, select the Device Manager tab and then look at you modem properties, and mouse properties to see which com ports they are assigned to. Then check under Ports and make sure that the com port you are trying to open is not the same as the mouse or modem(s). If it is you will need to consult your computer manual about how to re-assign your ports. *Note: This is a fairly tricky task and should be done only as a last resort or by someone who can put things back if this still doesn't solve the problem.
The second most common error is Could not open port. This is usually caused by a bad connection between the computer and the VTR or the computer and the TC translation device. If you are connecting to a VTR, check to make sure that the RS-232 to RS-422 adapter is connected in the correct way. (The RS-232 side of the adapter should be connected to the PC.) Also, check that the D connectors on the cable are all fully seated with the adapter ends and the VTR com port. If you are using a TC translation device, make sure that it is properly connected to the PC com port.