With the requirements of the system defined the next three steps in the process are straight-forward and are largely guided by the first step in the process. The IC selection process will allow for quick disqualifications of parts that don’t meet the absolute needs of the use case. With each additional requirement added to the RS-485 system the pool of potential parts will decrease limiting the ability of many parts to be used across varied use cases. With general bus architecture informed by the standard and with system definition finalized the actual application design has largely been tackled throughout the definition and IC selection process. Finally, there is the question of validation and qualification – depending on the end user they may do IC and system level qualification to see if the IC and system are functioning as they should. These two events are typically separate where designers don’t usually have to re-qualify the same device over multiple projects so parts that fit multiple niches can be beneficial to the entire process.

With proper requirements defined the last three generalized steps are straight-forward. However, with the large amount of variability of RS-485 implementations even similar use cases could require different IC selections – adding a level of complexity to the design and qualification processes which could lead to multiple designs and additional qualification procedures.