Siemens SCALANCE X-300 Configuration Manual page 364

Appendix A
A.1 PC attachment at the serial interface of a SCALANCE X400
X-400 pinout (null modem cable)
For connection to the PC, a null modem cable has either a 9-pin or a 24-pin D-sub female
connector and a 9-pin D-sub female connector at the other end. The following table shows
the pin assignment for both cable variants:
Figure A-1
Note
With SIMATIC programming devices, the serial interface may be a 25-pin female connector.
In this case, use a commercially available gender changer (25-pin male to 25-pin male).
364
Pin assignment table
Configuration Manual, 10/2014, C79000-G8976-C187-22
SCALANCE X-300 / X-400