The maximum cable length depends on the baud rate and the transmission line characteristics. As a general rule, the maximum cable length is inversely proportional to the baud rate. For example, at 9600bps, the maximum cable length is around 4000ft (1219m), while at 115200bps, it's around 100ft (30m).
To ensure reliable communication in noisy environments, use twisted-pair cables, keep the cable length as short as possible, and use shielding to reduce electromagnetic interference (EMI). Additionally, consider using a common-mode choke or a ferrite bead to filter out high-frequency noise.
The main difference is the operating temperature range. The MAX485EESA-T has an extended temperature range of -40°C to +125°C, while the MAX485ESA-T has a temperature range of 0°C to +70°C. The 'E' in the part number indicates an extended temperature range.
Yes, the MAX485EESA-T can be used for half-duplex communication. To do so, connect the DE (driver enable) pin to the RE (receiver enable) pin, and use a single twisted-pair cable for both transmission and reception.
To handle bus contention in a multi-master RS-485 network, use a collision detection mechanism, such as monitoring the bus for collisions and retrying transmission when a collision is detected. You can also use a master-slave architecture, where one master device controls the bus and the other devices act as slaves.
MAX485EESA-T datasheet
by Maxim Integrated Products
