PP Presentation
- RxD + 8 O--+
- RxD - 5 O-----------------------O 3 RD
- TxD - 3 O-----------------------O 2 TD
- Hsko 1 O--+
- Hski 2 O--+--------------------O 20 DTR
- In RS-232 data signals are inverted (marking is minus) control signals are not (marking is plus). Thus the TxD- signal drives the modem.