The RS-232 interface is not designed for long data cables (no differential signals). The maximal cable length is mainly defined by the data rates of the RS-232 interface. See the following guidelines:
- 9’600 Baud → up to 152m
- 19’200 Baud → up to 15m
- 115’200 Baud → up to 2m
The cable length is also influenced positive or negative by other factors:
- Quality of the cable (Shielding, wire resistance, etc.)
- Environmental conditions (Disturbance sources like motors, etc.)