Teach you how to use Rails to write web applications. For that, you probably ought to start with Rolling with Ruby on Rails. This is an introduction and road map to the many features of Rails.
The purpose of this application note is to describe the main elements of
an RS-422 and RS-485 system. This application note attempts to cover
enough technical details so that the system designer will have considered all
the important aspects in his data system design. Since both RS-422 and RS-
485 are data transmission systems that use balanced differential signals, it is
appropriate to discuss both systems in the same application note. Throughout
this application note the generic terms of RS-422 and RS-485 will be used to
represent the EIA/TIA-422 and EIA/TIA-485 Standards.
