Multiplexer for use in data processing system

Claim 2

A multiplexer for communicating between a plurality of first apparatuses and a second apparatus, comprising: a plurality of first reception means for receiving data from said plurality of first apparatuses, respectively; a second reception means for receiving data from said second apparatus, the data received by said second reception means including an identification code for indicating one or more first apparatuses; a plurality of first transmission means for transmitting data to said plurality of first apparatuses, respectively; second transmission means for transmitting data to said second apparatus; first selection means for selecting one of said plurality of first reception means so that the data received by said selected first reception means are transmitted to said second apparatus through said second transmission means; second selection means for selecting at least one of said plurality of first transmission means so that the data received by said second reception means are transmitted to at least one of said plurality of first apparatuses through said selected first transmission means; and control means for controlling said second means in response to said identification code, said control means being operable in the following first and second operation modes, in said first operation mode, said control means enabling said second selection means to select the first transmission means corresponding to the first reception means selected by said first selection means, and in said second operation mode, said control means enabling said second selection means to select all of said plurality of first transmission means.

Claim 3

A multiplexer as claimed in claim 1, wherein said first selection means selects a next one of said plurality of first reception means when said selected first reception means has completely received the data from its respective first apparatus.

Claim 4

A multiplexer as claimed in claim 1, wherein said first selection means selects a next one of said plurality of first reception means when said selected first reception means has not received data for a predetermined time.

Claim 5

A multiplexer for communicating between a plurality of first apparatuses and a second apparatus, comprising: selection means for selecting one of said plurality of first apparatuses; first communication means for receiving data from said first apparatus selected by said selection means and for transmitting the data received from said selected first apparatus to said second apparatus; second communication means for receiving data from said second apparatus, the data received from said second apparatus including an identification code for indicating one or all of said first apparatuses, and for transmitting the data received from said second apparatus to said first apparatus selected by said selection means; third communication means for receiving data from said second apparatus and for transmitting the data received from said second apparatus to all of said plurality of first apparatuses; and control means, in response to said identification code, for selectively actuating one of said second and third communication means according to the data received from said second apparatus.

Claim 6

A multiplexer for communicating between a plurality of first apparatuses and a second apparatus, comprising: selection means for selecting one of said plurality of first apparatuses; first communication means for receiving data from said first apparatus selected by said selection means and for transmitting the data received from said selected first apparatus to said second apparatus; second communication means for receiving data from said second apparatus, the data received from said second apparatus including an identification code for indicating one or all of said first apparatuses, and for transmitting the data received from said second apparatus to said first apparatus selected by said selection means; third communication means for receiving data from said second apparatus and for transmitting the data received from said second apparatus to all of said plurality of first apparatuses; and control means, in response to said identification code, for selectively actuating one of said second and third communication means according to the data received from said second apparatus.

Claim 7

A multiplexer as claimed in claim 4, wherein said selection means selects a next one of said plurality of first apparatuses when the first communication means has completely received the data from said first apparatus selected by said selection means.

Claim 8

A multiplexer as claimed in claim 4, wherein said selection means selects a next one of said plurality of first apparatuses when the first communication means has not received data from said first apparatus selected by said selection means for a predetermined time.

Claim 9

A multiplexer for communicating between a plurality of data processing units and a printer system, comprising: a plurality of first reception means for receiving data from said plurality of data processing units, respectively; second reception means for receiving data from said printer system, the data received by said second reception means including an identification code for indicating one or more data processing units; a plurality of first transmission means for transmitting data to said plurality of data processing units, respectively; second transmission means for transmitting data to said printer system; first selection means for selecting one of said plurality of first reception means so that the data received by said selected first reception means are transmitted to said printer system through said second transmission means; second selection means for selecting at least one of said plurality of first transmission means so that the data received by said second reception means are transmitted to at least one of said plurality of data processing units through said selected first transmission means; and control means for controlling said second selection means in response to said identification code, said control means being operable in the following first and second operation modes, in said first operation mode, said control means enabling said second selection means to select the first transmission means corresponding to the first reception means selected by said first selection means, and in said second operation mode, said control means enabling said second selection means to select all of said plurality of first transmission means.

Claim 10

A multiplexer for communicating between a plurality of data processing units and a printer system, comprising: a plurality of first reception means for receiving data from said plurality of data processing units, respectively; second reception means for receiving data from said printer system, the data received by said second reception means including an identification code for indicating one or more data processing units; a plurality of first transmission means for transmitting data to said plurality of data processing units, respectively; second transmission means for transmitting data to said printer system; first selection means for selecting one of said plurality of first reception means so that the data received by said selected first reception means are transmitted to said printer system through said second transmission means; second selection means for selecting at least one of said plurality of first transmission means so that the data received by said second reception means are transmitted to at least one of said plurality of data processing units through said selected first transmission means; and control means for controlling said second selection means in response to said identification code, said control means being operable in the following first and second operation modes, in said first operation mode, said control means enabling said second selection means to select the first transmission means corresponding to the first reception means selected by said first selection means, and in said second operation mode, said control means enabling said second selection means to select all of said plurality of first transmission means.

Claim 11

The multiplexer as claimed in claim 7, wherein said first selection means selects a next one of said plurality of first reception means when said selected first reception means has completely received the data from its respective data processing unit.

Claim 12

The multiplexer as claimed in claim 7, wherein said first selection means selects a next one of said plurality of first reception means when said selected first reception means has not received data for a predetermined time.

Claim 13

A multiplexer for communicating between a plurality of data processing units and a printer system, comprising: selection means for selecting one of said plurality of data processing units; first communication means for receiving data from said one data processing unit selected by said selection means and for transmitting the data received from said selected data processing unit to said printer system; second communication means for receiving data from said printer system, the data received from said printer system including an identification code for indicating one or all of said data processing units, and for transmitting the data received from said printer system to said one data processing unit selected by said selection means; third communication means for receiving data from said printer system and for transmitting the data received from said printer system to all of said plurality of data processing units; and control means, in response to said identification code, for selectively actuating one of said second and third communication means according to the data received from the printer system.

Claim 14

A multiplexer for communicating between a plurality of data processing units and a printer system, comprising: selection means for selecting one of said plurality of data processing units; first communication means for receiving data from said one data processing unit selected by said selection means and for transmitting the data received from said selected data processing unit to said printer system; second communication means for receiving data from said printer system, the data received from said printer system including an identification code for indicating one or all of said data processing units, and for transmitting the data received from said printer system to said one data processing unit selected by said selection means; third communication means for receiving data from said printer system and for transmitting the data received from said printer system to all of said plurality of data processing units; and control means, in response to said identification code, for selectively actuating one of said second and third communication means according to the data received from the printer system.

Claim 15

The multiplexer as claimed in claim 10, wherein said selection means selects a next one of said plurality of data processing units when the first communication means has completely received the data from said data processing unit selected by said selection means.

Claim 16

The multiplexer as claimed in claim 10, wherein said selection means selects a next one of said plurality of data processing units when the first communication means has not received data from said data processing unit selected by said selection means for a predetermined time.

Claim 17

A multiplexer for communicating between a plurality of first apparatuses and a second apparatus, comprising: a plurality of data reception buses for receiving data from said plurality of first apparatuses, respectively; a plurality of data transmission buses for transmitting data to said plurality of first apparatuses, respectively; communication means for communicating data with said second apparatus; a plurality of data reception gates provided on said plurality of data reception buses, respectively; a plurality of data transmission gates provided on said plurality of data transmission buses, respectively; a bus interface connected with said plurality of data reception gates and said plurality of data transmission gates for selectively opening and closing them; a controller connected with said bus interface for controlling a gate opening operation in first and second operational modes, in said first operation mode, said controller enabling said bus interface to open one of said plurality of data reception gates and one of said plurality of data transmission gates corresponding to each other, and in said second operation mode, said controller enabling said bus interface to open all of said plurality of data transmission gates.

Claim 18

A multiplexer for communicating between a plurality of first apparatuses and a second apparatus, comprising: a plurality of data reception buses for receiving data from said plurality of first apparatuses, respectively; a plurality of data transmission buses for transmitting data to said plurality of first apparatuses, respectively; communication means for communicating data with said second apparatus; a plurality of data reception gates provided on said plurality of data reception buses, respectively; a plurality of data transmission gates provided on said plurality of data transmission buses, respectively; a bus interface connected with said plurality of data reception gates and said plurality of data transmission gates for selectively opening and closing them; a controller connected with said bus interface for controlling a gate opening operation in first and second operational modes, in said first operation mode, said controller enabling said bus interface to open one of said plurality of data reception gates and one of said plurality of data transmission gates corresponding to each other, and in said second operation mode, said controller enabling said bus interface to open all of said plurality of data transmission gates.

Claim 19

The multiplexer as claimed in claim 13, wherein said communication means includes a second data reception bus for receiving data from said second apparatus and a second data transmission bus for transmitting data to said second apparatus.

Claim 20

The multiplexer as claimed in claim 14, wherein said communication means includes a second data reception gate provided on said second data reception bus and a second data transmission gate provided on said second data transmission bus.

Claim 21

The multiplexer as claimed in claim 13, wherein said controller controls said gate opening operation in response to an identification code which is transmitted from said second apparatus for indicating one or more first apparatuses.