MacroVison FX Serial Port

There is an RS-232 (I assume) serial port on the MicroVision FX.  However, the manual has no information as to what it might be used for.  Does anyone have documentation of what this does?  Is it an output for a serial printer?  Is it a serial remote control input?  A factory diagnostic port?  I have a client who would like to remotely control this board.  Is it possible through the serial port?  (They don't have the 25-pin remote go interface)