The maximum cable length for the DS485M/NOPB is dependent on the baud rate and the type of cable used. As a general guideline, the maximum cable length is around 4000 feet (1219 meters) at 9600 bps, but this can be affected by factors such as cable quality, noise, and termination.
The DS485M/NOPB requires a 120-ohm termination resistor at each end of the bus to prevent signal reflections and ensure reliable data transmission. The termination resistors should be connected between the differential lines (A and B) and can be installed at the extreme ends of the bus.
The maximum number of nodes that can be connected to a DS485M/NOPB network is 32. This is because the DS485M/NOPB uses a 5-bit node address, which allows for up to 32 unique addresses.
Yes, the DS485M/NOPB can be used in a multi-drop configuration, where multiple nodes are connected to the same bus. However, the total number of nodes should not exceed 32, and each node should have a unique address.
The DS485M/NOPB does not have built-in error detection or correction capabilities. It is up to the system designer to implement error detection and retry mechanisms in the application software to ensure reliable data transmission.
DS485M/NOPB datasheet
by Texas Instruments
