Controller for two-way serial transmission and adapter for serial port

A controller having a central processing unit with a two-way serial communication function, comprising:

• a serial port adapter including a serial data output port for outputting data transmitted from said central processing unit, a serial data input port for inputting data transmitted to said central processing unit, an output buffer circuit, an input buffer circuit, and a data I/O terminal for transferring serial data to and from the outside;
• said data I/O terminal being connected to said serial data output port via said output buffer circuit, and said data I/O terminal being connected to said serial data input port via said input buffer circuit, such that two-way serial data communication with said central processing unit can be conducted via said data I/O terminal and said serial data output and input ports.

Apparatus comprising a plurality of operating units and a corresponding plurality of control units each controlling a respective operating unit,

• wherein each said control unit includes a central processing unit and a serial communication device connected to said central processing unit, said serial communication device comprising a serial data I/O terminal, a serial data output port for outputting data transmitted from said central processing unit, a serial data input port for inputting data transmitted to said central processing unit, an output buffer circuit connecting said serial data output port to said serial data I/O terminal, and an input buffer circuit connecting said serial data input port to said serial data I/O terminal, such that two-way serial communication with said central processing unit can be conducted via said serial data I/O terminal and said serial data output and input ports, and
• wherein the respective serial data I/O terminals of the serial communication devices of said plurality of control units are all connected to a single two-way serial data communication line.

Apparatus comprising a plurality of operating units and a corresponding plurality of control units each controlling a respective operating unit,

• wherein each said control unit includes a central processing unit and a serial port adapter connected to said central processing unit, said serial port adapter comprising a serial data I/I/O terminal, a serial data output buffer circuit connecting serial data I/O terminal to said central processing unit for transferring data transmitted from said central processing unit, and a serial data input buffer circuit connecting said serial data I/O terminal to said central processing unit for transferring data transmitted to said central processing unit, such that two-way serial communication with said central processing unit can be conducted via said serial data I/O terminal and said serial data output and input buffer circuits, and
• wherein the respective serial data I/I/O terminals of the serial port adapters of said plurality of control units are all connected to a single two-way serial data communication line.