Saturn S300 Series Service Manual page 161

3．Turn off the printer power, and then move the both "Jumper" to the left two needles, so the
printer will be in the status of "Ready for Writing into".
4．Connect one end of the programming cable with RS485 converter, insert the converter into
the updating connector, the other end of the programming cable should be connected with
the communication connector of 9 needles in PC.(usually the COM1 is for the PC while it is
not sure that which one is for portable PC.)
Turn on the power supply for the printer, and the LCD screen will display the
"Communication Fault", this is normal because the "Jumper" have been connected to the
left two needles and the printer is on "Ready for Writing into" status but not normal running
status.
Appendix 6 - S400 Series Upgrade Introduction
8-13