What is the minimum distance between two devices on PROFIBUS DP?
When the transmission speed is 1.5 Mbits/s or higher, it is highly recommended to have at least 1 m of cable between 2 devices. The cable compensates for the input capacitance of both devices to preserve the common impedance. When the devices are very close together, there is a large chance that reflections in the data communication (small short circuits) can be caused by the input capacitance. The effect is much less common at transmission speeds lower than 1.5 Mbits/s.
