An RS-232 serial port uses a DB-9 male connector and always operates as COM1. You can use a standard DB-9 serial cable with this port. The FX30E/FX60E is a serial Data Terminal Equipment (DTE) device, so connecting another DTE device (computer) requires a null modem cable. To connect the FX30E/FX60E to a Data Communication Equipment (DCE) device (modem), use a straight-through cable. Table 4 provides the standard serial DB-9 pinouts.