Controlling device for switching serial communication port and light communication port and its driving method

Claim 1

A switch controlling device of a wired serial communication port and a light serial communication port comprising: a single asynchronous communication part for executing one of producing a control signal for controlling lines or a modem, said lines or modem being connected to exterior peripheral equipment, and transmitting an information signal such as conditions of lines or modem inputted from the exterior peripheral equipment, wherein said execution is effected when an information signal containing a control command or data is inputted; a switch for producing a switch signal which is used for selecting one of the light serial communication port and the wired serial communication port; a micro-controlling means for outputting a control signal which causes selection of the wired serial communication port as a transmit channel and which de-activates the light serial communication port as a transmit channel by cutting off power to the light serial communication port when the light serial communication port is not selected by the switch signal produced by the switch, and for outputting a control signal which activates the light serial communication port as a transmit channel by applying power to the light serial communication port when the light communication serial port is selected by the switch signal; at least one multiplexer for selecting one of the wired serial communication port and the light serial communication port as the transmit channel according to a control signal inputted from said micro-controlling means; an EIA driver electrically connected to said asynchronous communication part via the transmit channel selected by said at least one multiplexer; and a light signal input/output part electrically connected to said asynchronous communication part via the transmit channel selected by said at least one multiplexer and to which power is applied or cut off according to the control signal outputted by said micro-controlling means.

Claim 7

A method for driving a switch controlling device of a wired serial communication port and a light serial communication port comprising the steps of: providing a single asynchronous communication part; reading a switch signal when power is applied to the switch controlling device; determining from the read switch signal whether the light communication port is selected; selecting as a transmit channel the wired serial communication port, by connecting said asynchronous communication part to said wired serial communication port and simultaneously cutting off power to the light communication port when the light serial communication port is not selected; and selecting as a transmit channel the light serial communication port, by connecting said asynchronous communication part to said light serial communication port and simultaneously applying power to the light serial communication port when the light serial communication port is selected.

Claim 8

A method for driving a switch controlling device of a wired serial communication port and a light serial communication port comprising the steps of: providing a single asynchronous communication part; reading a switch signal when power is applied to the switch controlling device; determining from the read switch signal whether the light communication port is selected; selecting as a transmit channel the wired serial communication port, by connecting said asynchronous communication part to said wired serial communication port and simultaneously cutting off power to the light communication port when the light serial communication port is not selected; and selecting as a transmit channel the light serial communication port, by connecting said asynchronous communication part to said light serial communication port and simultaneously applying power to the light serial communication port when the light serial communication port is selected.