ABSTRACT
Serial communications is one of the most popular means of data transmission used in the computer as well as the building automation industry. Serial communication is standardized and is defined by Electronic Industries Association (EIA) or Recommended Standards standards. The application of the RS-232 data transmission standard has many variations and associations with different computing and communications hardware. An asynchronous environment is characterized by transmission of character bits enclosed by a start and stop bit. These are called synchronizing signals. Synchronous data communications were established to increase the volume and speed of data sent over the network. The EIA has issued the above standard with the prefix “EIA” in 1983 under the name: “Electrical Characteristics of Generators and Receivers for Use in Balanced Digital Multi Point Systems.” The interchange system includes so-called generators and receivers of communication signals and balanced interconnecting cable with terminating resistors.
