The maximum cable length supported by the DS485MX/NOPB is 4000 feet (1219 meters) at a data rate of 100 kbps, but it can be extended up to 10,000 feet (3048 meters) at a lower data rate.
To ensure reliable data transmission over long distances, use a twisted-pair cable, keep the cable away from noise sources, and use a common-mode choke or ferrite bead to reduce electromagnetic interference (EMI).
The maximum number of nodes that can be connected to a single bus using the DS485MX/NOPB is 32, but it's recommended to limit the number of nodes to 10-15 to maintain signal integrity.
To terminate the bus properly, use a 120-ohm resistor at each end of the bus, and ensure that the termination resistors are connected between the differential lines (A and B) and the ground.
The recommended baud rate for the DS485MX/NOPB is 100 kbps, but it can operate up to 500 kbps. A higher baud rate reduces the maximum cable length, so it's essential to balance the baud rate with the cable length to ensure reliable data transmission.
DS485MX/NOPB datasheet
by Texas Instruments
