In order for the Serial icon to operate correctly there are certain software and hardware guidelines that must be followed. Having the mouse active on the screen can cause problems. If the mouse is moving during data acquisition it can interfere with the serial communication and cause points to be missed. Make sure that the correct modem cable is being used. If both the computer and the external serial device have the same connection a null modem must be used.
Continuous mode can lead to missed characters in the input data.
This is due to the one character input buffer. If some characters have already been sent when the serial icon accesses the line then those characters are missed. This can be overcome, to a degree, by using two input commands, one after the other. In this way a whole line of data is read, although the first line is still lost. Make sure that the user knows that there is a serial configuration in the menu that needs to be set up to perform serial communication.