To connect a PC to the MPI programming interface you need a MPI programming adapter. In case of the S7-200 PPI interface, a simple RS232 to RS485 adapter is sufficient.
Code:
Pin No. Notation Signalname Direction (of cable)
1 NC Not Connected
2 M24V Ground of the 24V In
3 Ltg_B Data line B BiDir.
4 RTS-AS Request to Send from the PLC In
5 M5V Ground of the 5V In
6 P5V 5V output Out
7 P24V 24V Supply input In
8 Ltg_A Data line A BiDir
9 RTS-PG Request to Send to the PLC Out
The additional serial interface of S7-300 CPUs 313C-2 PtP and 314C-2 PtP also uses a RS422/485 physical layer and needs a converter to connect to a PC.
The PtP 15p connector pin-out ist shown in this document
https://support.automation.siemens....ctions_operating_instructions_en-US_en-US.pdf