Device control method and program recorded medium on which the method is recorded

Abstract

Detecting an input source of a signal of a device connected to a bus and determining whether the signal is converted, extracted, multiplexed, or processed. Efficiently controlling the connection of each unit connected on the bus. Issuing a command for detecting the output plug or source plug as the signal source. The unit or subunit receiving this command shows the signal source. Obtaining information showing whether a subunit is present in the unit or not.

1 . A device control method in a system comprising
 a) a unit including at least one of an input plug for providing a source of signal input and an output plug for providing a source of signal output, and   b) a subunit having at least one of a destination plug for providing a source of signal input and a source plug for providing a source of signal output to a bus, said method comprising at least one of the steps of:   a) requesting the output plug of the unit to designate the source plug of the subunit as a signal source;   b) requesting the destination plug of the subunit to designate the input plug of the unit as the signal source;   c) requesting the output plug of the unit to designate the input plug of the unit as the signal source; and   d) requesting the destination plug of the subunit to designate the source plug of the subunit as the signal source.   
   
   
       2 . A device control method in a system comprising a first unit and a second unit, each of said first and second units having
 a) at least one of an input plug for providing a source of signal input and an output plug for providing a source of signal output, and   b) a first subunit and a second subunit, each of said subunits having at least one of a destination plug for signal input and a source plug for providing a source of signal output to a bus, comprising:   at least one of the steps of   a) requesting the destination plug of the first subunit included in the first unit to designate the input plug of the first unit as the source of signal, and   b) requesting the output plug of the first unit to designate the input plug of the first unit as the source of signal; and   at least one of the steps of   c) requesting the output plug of the second unit to designate the source plug of the second subunit included in the second unit as the source of signal, and   d) requesting the output plug of the second unit to designate the input plug of the second unit as the source of signal; and   the step of   e) requesting the input plug of the first unit and the output plug of the second unit to connect to each other, after at least one of the steps a) and b) and at least one of the steps c) and d).   
   
   
       3 . The device control method of  claim 1 , further comprising the step of:
 e) determining whether or not a further subunit is present along a path connecting at least one of the plugs designated in at least one of the steps a) to d) as the signal source.   
   
   
       4 . The device control method of  claim 1 , further comprising the step of:
 e) determining whether or not the signal is processed along a path connecting at least one of the plugs designated in at least one of the steps a) to d) as signal source.   
   
   
       5 . The device control method of  claim 4 , further comprising the steps of:
 f) determining whether or not the signal along the path is a multiplexed signal having multiple program contents, and   g) determining whether or not part of the multiple program contents is extracted along the path when the signal is the multiplexed signal having multiple programs.   
   
   
       6 . The device control method of  claim 4 , further comprising the steps of:
 f) determining whether or not the signal along the path includes video data; and   g) determining whether or not data is added to the video data to enable display of the added data when the signal includes video data.   
   
   
       7 . The device control method of  claim 1 , further comprising the step of:
 e) determining from at least one of the unit and the subunit that a further signal has issued from at least one of the unit and the subunit after the signal source has been designated in accordance with at least one of the steps a) to d)   
   
   
       8 . A device control method in a system comprising a plurality of units including an input plug for signal input and an output plug for signal output to a bus, comprising the steps of:
 a) providing a signal from a first unit to a second unit to request a point-to-point connection between the second unit and a third unit; and   b) establishing point-to-point connection between the second unit and the third unit in response to the signal.   
   
   
       9 . The device control method of  claim 8 , wherein the signal requesting the point-to-point connection includes information for specifying a unit as an object of the point-to-point connection. 
   
   
       10 . The device control method of  claim 8 , wherein the second unit establishes point-to-point connection with the first unit. 
   
   
       11 . The device control method of  claim 8 , wherein the signal requesting the point-to-point connection includes information specifying a plug as an object of the point-to-point connection. 
   
   
       12 . The device control method of  claim 8 , further comprising the step of:
 c) determining whether or not the second unit previously established point-to-point connection with a unit other than the third unit designated by the signal, and if previously established,
 1) terminates the previously established point-to-point connection between the second unit and the third unit; and 
 2) establishing a point-to-point connection between the second unit and the other unit.