Designers of industrial datacom systems often ask, “What is the most cost-effective implementation for multidropped, medium-speed, serial data communications?” What data rates can be reliably achieved over what distance, and how? The design trade-off has always been less distance at a higher rate, or greater distance at a lower rate. So, the crucial question is: “How far can you reliably transmit and receive data at a specified data rate?” In this application note, the MAX3469 — a 40Mbps, Profibus RS-485/RS-422 transceiver — is used to demonstrate RS-485 performance.