Abstract:
Communicating apparatus to be provided between an intermediate line and transmission lines to establish data communications, the intermediate line and the transmission lines having in combination data pass therethrough, the transmission lines including first line and second line  1  and  2 , is designed to select the transmission line from among the first and second lines  1  and  2  based on detecting the data passing through each of the first and second lines  1  and  2  so as to transmit data without collision.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a communicating apparatus for establishing communications with the help of an intermediate line such as the internet and ISDN (Integrated Services Digital Network), and more particularly to a remote control system for ensuring communications to allow a controller in a remote area to control a targeted apparatus via the intermediate line. 
   DESCRIPTION OF THE RELATED ART 
   The conventional remote control system of this type is shown in  FIG. 7  as comprising transmission lines provided in a local area (referred to simply as “local transmission lines”)  1   b  and  2   b,  transmission lines provided in a remote area (referred to simply as “remote transmission lines”)  1   a  and  2   a,  an intermediate line  3  provided between the local area and the remote area, a communicating apparatus (referred to simply as “local communicating apparatus”)  10   b  provided between the local transmission lines  1   b  and  2   b  and the intermediate line  3 , a communicating apparatus (referred to simply as “remote communicating apparatus”)  10   a  provided between the intermediate line  3  and the remote transmission lines  1   a  and  2   a,  a controller (referred to simply as “local controller”)  20   b  connected to the local communicating apparatus  10   b  via the local transmission lines  1   b  and  2   b,  a controller (referred to simply as “remote controller”)  20   a  connected to the remote communicating apparatus  10   a  via the remote transmission lines  1   a  and  2   a,  a watching system apparatus (referred to simply as “targeted apparatus”)  30  connected to the local communicating unit  10   b  via the local transmission lines  1   b  and  2   b,  a plurality of cameras  31 , a detecting unit  32  having sensors for detecting objects such as intruders. 
   Here, the intermediate line  3  is indicative of a network such as, for example, ISDN (Integrated Service Digital Network), the intermediate line having terminals to be connected in each of the remote area and the local area. 
   The local transmission lines include a receiving line (indicative of a first line of the local transmission lines)  1   b  and a transmitting line (indicative of a second line of the local transmission lines)  2   b . The remote transmission lines include a receiving line (indicative of a first line of the remote transmission lines)  1   a  and a transmitting line (indicative of a second line of the remote transmission lines)  2   a.  Each of the local transmission lines and the remote transmission lines may have, for example, unbalanced type signal pass therethrough. The term “receiving line” herein described is intended to indicate a line which allows the controller to receive the data transmitted by the targeted apparatus  30 . The term “transmitting line” herein described is intended to indicate a line which allows the controller to transmit the data to the targeted apparatus  30 . 
   The conventional communicating apparatus  10  of this type is shown in  FIG. 8  as comprising interface means  101  for transmitting and receiving the data via the intermediate line, multiplexer/demultiplexer  102  for multiplexing video data, audio data, and control data into data stream to be outputted to the interface means  101  and for demultiplexing the data stream received by the interface means  101  via the intermediate line into the video data, the audio data, and the control data, transmission controlling means  103  having the transmitting means  112  transmit the data via the second line and having the receiving means  111  receive the data via the first line, receiving means  111  for receiving the data via the first line, and transmitting means  112  for transmitting the data via the second line. The transmission controlling means  103  has buffer memory  115  for buffering the data received by the receiving means  111  and buffer memory  116  for buffering the data to be transmitted via the second line. 
   The following description will now be directed to the process of the remote controller  20   a  forming part of the conventional remote control system with reference to  FIG. 8 . The control signal is initially transmitted by the remote controller  20   a  to the remote communicating apparatus  10   a  via the transmitting line  1   a  of the remote transmission lines. The control signal transmitted by the remote controller  20   a  is then received by the remote communicating apparatus  10   a  before the control signal is transmitted by the remote communicating apparatus  10   a  to the local communicating apparatus  10   b.  The control signal transmitted by the remote communicating apparatus  10   a  is then received by the local communicating apparatus  10   b  before the control signal is transmitted by the communicating apparatus  10   b  to the targeted apparatus  30  via transmitting line  2   b  of the local transmissions lines. On the other hand, the response signal with respect to the control signal is transmitted by the targeted apparatus  30  to the local communicating apparatus  10   b  via the receiving line of the transmission line  1   b.  The response signal transmitted by the targeted apparatus  30  is received by the local communicating apparatus  10   b  before the response signal transmitted by the targeted apparatus  30  is transmit by the local communicating apparatus  10   b  to the remote communicating apparatus  10   a.  The response signal transmitted by the remote communicating apparatus  10   b  is then received by the remote communicating apparatus  10   a  before the response signal transmitted by the communicating apparatus  10   a  is finally transmitted by the remote communicating apparatus  10   a  to the remote controller  20   a  via the receiving line of the transmission lines. 
   The following description will now be directed to the process of the local controller  20   b  forming part of the conventional remote control system. The control signal is initially transmitted by the local controller  20   b  to the targeted apparatus  30  via the transmitting line  2   b  of the remote transmission lines. On the other hand, the response signal with respect to the control signal received by the targeted apparatus  30  is then transmitted by the targeted apparatus  30  to the local controller  20   b  via the receiving line  1   b  of the transmission line. 
   From the foregoing description, it will be understood that the conventional remote control system allows one of the remote controller  20   a  and the local controller  20   b  to control the targeted apparatus  30 . 
   The conventional remote control system thus constructed in the above encounters such a problem that the targeted apparatus is irregularly controlled by each of the remote controller and the local controller after the actual execution state with respect to the targeted apparatus is in disagreement with the execution state finally stored by the remote controller with respect to the targeted apparatus due to the fact that the control data transmitted by one of the remote controller and the local controller to the targeted apparatus cannot be received by the other of the remote controller and the local controller, this leading to the fact that the targeted apparatus is out of control. Consequently, the control data is transmitted by the remote controller  20   a  to the targeted apparatus  30  after the judgment is made by the remote controller  20   a  on whether or not the targeted apparatus  30  is controlled by the local controller  20   b.  Although the intruder, for example, was detected by the targeted apparatus, the camera cannot be controlled immediately by the remote controller. 
   It is, therefore, an object of the present invention to provide a communicating apparatus and a remote control system which can establish data communications to allow the remote controller to control the targeted apparatus with the help of an intermediate line. 
   It is another object of the present invention to provide a communicating apparatus and a remote control system which can allow each of the local controller and the remote controller to control the targeted apparatus. 
   SUMMARY OF THE INVENTION 
   In accordance with a first aspect of the communicating apparatus according to the present invention, there is provided a communicating apparatus to be provided between an intermediate line and transmission lines to establish data communications, the intermediate line and the transmission lines having in combination data pass therethrough, the transmission lines including first line and second line, comprising: first receiving means for receiving the data via the first line; second receiving means for receiving the data via the second line; interface means for transmitting via the intermediate line the data received by the first receiving means via the first line and the data received by the second receiving means via the second line, and for receiving the data transmitted by an other communicating apparatus via the intermediate lines; first transmitting means for transmitting via the second line the data transmitted via a first receiving means of the other communicating apparatus; first detecting means for detecting the data transmitted via the second line; first controlling means for switching between an operative state and an inoperative state of the first transmitting means based on the data detected by the first detecting means; second transmitting means for transmitting via the first line the data transmitted via a second receiving means of the other communicating apparatus; second detecting means for detecting the data transmitted via the second line; and second controlling means for switching between an operative state and an inoperative state of the second transmitting means based on the data detected by the second detecting means. The communicating apparatus according to the present invention thus constructed as previously mentioned can allow the remote controller in the remote area to control the targeted apparatus in the local area via the intermediate line, and allow each of the remote controller in the remote area and the local controller in the local area to control the targeted apparatus. 
   In accordance with a another aspect of the remote control system according to the present invention, there is provided a remote control system for ensuring data communications via three different lines including remote transmission lines provided in a remote area, local transmission lines provided in a local area, and intermediate line provided between the local area and the remote area, each of the remote transmission lines and the local transmission lines including first line and second line, the three different lines having in combination data pass therethrough, comprises: local communicating apparatus provided between the intermediate line and the local transmission lines, the local communicating apparatus being constituted by a communicating apparatus described in claim  1 ; remote communicating apparatus provided between the intermediate line and the remote transmission lines, the remote communicating apparatus being constituted by a communicating apparatus described in claim  1 ; targeted apparatus connected to the local communicating apparatus via the local transmissions lines; local controller for controlling the targeted apparatus, the local controller being connected to both the local communicating apparatus and the targeted apparatus via the local transmissions lines; and remote controller for controlling the targeted apparatus, the remote controller being connected to the remote communicating apparatus via the remote transmissions lines; wherein the local controller having first receiving means for receiving the data via the first line of the local transmission lines, second receiving means for receiving the data via the second line of the local transmission lines, transmitting means for transmitting the data via the second line of the local transmission lines, detecting means for detecting the data transmitted via the second line, and controlling means for controlling the transmitting means in such a manner that the transmitting means is selectively switched between under the operative state and under the inoperative state based on the data detected by the detecting means; and the remote controller having first receiving means for receiving the data via the second line of the remote transmission lines, second receiving means for receiving the data via the first line of the remote transmission lines, transmitting means for transmitting the data via the second line of the remote transmission lines, detecting means for detecting the data transmitted via the second line, and controlling means for controlling the first transmitting means in such a manner that the transmitting means is selectively switched between under the operative state and under the inoperative state based on the data detected by the detecting means. The remote control system according to the present invention thus constructed as previously mentioned can allow the remote controller in the remote area to control the targeted apparatus via the intermediate line, and allow each of the remote controller in the remote area and the local controller in the local area to control the targeted apparatus. 
   In the remote control system according to the present invention, a plurality of remote communicating apparatuses, a plurality of remote controllers, and a plurality of remote transmission lines is respectively provided in a plurality of remote areas, each of the remote controllers being operative to controlling the targeted apparatus  30  via the remote communicating apparatus in each of the remote areas. The remote control system according to the present invention thus constructed as previously mentioned can allow each of the remote controllers in the remote areas to control the targeted apparatus. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the present invention will become more apparent from the following detailed description when considered in connection with the accompanying drawings, wherein: 
       FIG. 1  is a block diagram of the embodiment of the remote control system according to the present invention; 
       FIG. 2  is a block diagram of the embodiment of the communicating apparatus according to the present invention; 
       FIG. 3  is a block diagram of the controller forming part of the remote control system according to the present invention shown in  FIG. 1 ; 
       FIG. 4  is a sequence diagram indicative of the process of the remote control system according to the present invention shown in  FIG. 1 ; 
       FIG. 5  is a sequence diagram indicative of the process of the remote control system according to the present invention shown in  FIG. 1 ; 
       FIG. 6  is a flowchart of the process of the communicating apparatus shown in  FIG.2 ; 
       FIG. 7  is a block diagram of the conventional remote control system; and 
       FIG. 8  is a block diagram of the conventional communicating apparatus. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The embodiments of the communicating apparatus and the remote control system according to the present invention will now be described in detail with reference to the drawings. 
     FIG. 1  is a block diagram of the embodiment of the remote control system according to the present invention. 
   The remote control system is shown in  FIG. 1  to comprise transmission lines  1   b  and  2   b  provided in a local area (referred to simply as “local transmission lines”), transmission lines  1   a  and  2   a  provided in a remote area (referred to simply as “remote transmission lines”), intermediate line  3  provided between the local area and the remote area, a communicating apparatus  10   b  provided between the local transmission lines  1   b  and  2   b  and the intermediate line  3  (referred to simply as “local communicating apparatus”), a communicating apparatus  10   a  to be provided between the intermediate line  3  and the remote transmission lines  1   a  and  2   a  (referred to simply as “remote communicating apparatus”), a controller  20   b  electrically connected to the local communicating apparatus  10   b  via the local transmission lines  1   b  and  2   b  (referred to simply as “local controller”), a controller  20   a  electrically connected to the remote communicating apparatus  10   a  via the remote transmission lines  1   a  and  2   a  (referred to simply as “remote controller”), a surveillance apparatus  30  connected to the local communicating unit  10   b  via the local transmission lines  1   b  and  2   b  (referred to simply as “targeted apparatus”), a plurality of cameras  31  connected to the targeted apparatus, a detecting unit  32  having sensors for detecting objects such as intruders. 
   Here, the intermediate line  3  is indicative of a network such as, for example, ISDN (Integrated Service Digital Network), the local communicating apparatus in the local area being connected to the remote communicating apparatus in the remote area via the intermediate line. 
   The local transmission lines include a receiving line  1   b  (indicative of a first line of the local transmission lines) and a transmitting line  2   b  (indicative of a second line of the local transmission lines), the remote transmission lines including a transmitting line  1   a  (indicative of a first line of the remote transmission lines) and a receiving line  2   a  (indicative of a second line of the transmission lines). Each of the local transmission lines and the remote transmission lines may have the data indicative of unbalanced type signal pass therethrough. The term “receiving line” herein described is intended to indicate a line which has each of the local controller and the remote controller receive the data transmitted by the targeted apparatus  30 . The term “transmitting line” herein described is intended to indicate a line which has each of the local controller and the remote controller transmit the data to the targeted apparatus  30 . 
     FIG. 2  is a block diagram of the embodiment of the communicating apparatus according to the present invention. The communicating apparatus  10  is shown in  FIG. 2  to comprise first receiving means  111  for receiving the data via the first line, second receiving means  121  for receiving the data via the second line, interface means  101  for transmitting via the intermediate line the data received by each of the first receiving means  111  and the second receiving means  121  and for receiving the data via the intermediate lines, multiplexing/demultiplexing means (indicative of multiplexing means and demultiplexing means)  102  for multiplexing the data containing video information, the data containing audio information, and the data containing control information into the data stream to be outputted to the interface means  101 , and for demultiplexing the data stream into the data containing the video information, the data containing the audio information, and the data containing the control information after receiving the data stream via the intermediate line, first transmitting means  112  for transmitting via the second line the data received by the interface means  101  via the intermediate line, first detecting means  113  for detecting the data transmitted via the second line, first controlling means  114  for controlling the first transmitting means  112  in such a manner that the first transmitting means  112  is selectively switched between under the operative state and the inoperative state based on the data detected by the first detecting means  113 , second transmitting means  122  for transmitting via the first line the data received by the interface means  101  via the intermediate line, second detecting means  123  for detecting the data transmitted via the second line, second controlling means  124  for controlling the second transmitting means  122  in such a manner that the second transmitting means  112  is selectively switched between under the operative state and the inoperative state based on the data detected by the second detecting means  123 , buffer memory  115  for buffering the data received by the first receiving means  111 , buffer memory  116  for buffering data received by the second receiving means  121 , buffer memory  125  for buffering the data to be transmitted via the intermediate line, and buffer memory  126  for buffering the data to be transmitted via the intermediate line. 
   The transmission controlling means  103  forming one of the local communicating apparatus and the remote communicating apparatus is operative to control the first transmitting means  112  to transmit via the second line the data received via the first line by the other of the local communicating apparatus and the remote communicating apparatus. The transmission controlling means  103  forming one of the local communicating apparatus and the remote communicating apparatus is operative to control the first transmitting means  112  to transmit via the first line the data received via the second line by the other of the local communicating apparatus and the remote communicating apparatus. The interface means  101  forming one of the local communicating apparatus  20   b  and the remote communicating apparatus  20   a  is operative to transmit the data containing the identification information indicative of the difference between the data transmitted by the first receiving means  111  via the first line and the data transmitted by the second receiving means  121  via the second line to the other of the local communicating apparatus  20   b  and the remote communicating apparatus  20   a.  The difference information indicative of the difference between the data transmitted by the first receiving means  111  via the first line and the data transmitted by the second receiving means  121  via the second line may be included, for example, the header information of the data to be transmitted by one of the local communicating apparatus  20   b  and the remote communicating apparatus  20   a,  the difference information being then transmitted to the transmission controlling means  103  of the other of the local communicating apparatus  20   b  and the remote communicating apparatus  20   a.    
   The transmission controlling means  103  is controlled to ensure that the data transmitted by one of the remote communicating apparatus and the local communicating apparatus via the intermediate line is prevented from being sent back by the interface means  101  of the other of the remote communicating apparatus  10   a  and local communicating apparatus  10   b  via the intermediate line. 
   Each of the first and second detecting means  113  and  123  is constituted by, for example, the standard logic integrated circuit such as a monostable multivibrator, the pulse signal being outputted by the monostable multivibrator during the time interval in which the data is detected. Each of the first and second transmitting means  112  and  122  is adapted to selectively assume two execution states including an operative state indicative of “enable” and an inoperative state indicative of “disable”. Each of the first and second controlling means  114  and  124  forming part of the transmission controlling means  103  is operative to control the two execution states of each of the first and second transmitting means  112  and  122  based on the pulse signal outputted by each of the first and second detecting means  113  and  123 . The operative state allows each of the first and second transmitting means  112  and  112  to transmit the data, the operative state allowing each of the first and second transmitting means  112  and  122  not to transmit the data. Each of the first and second transmitting means  112  and  122  is referred to as the transmitting data driver. 
   The local communicating apparatus  10   b  forming part of the remote control system shown in  FIG. 2  is operative to transmit the data via the intermediate line  3  after receiving the data transmitted by the local controller  20   b  via the transmitting line of the local transmission lines  2   b  in the additional reception step. The remote communicating apparatus  10   a  is operative to receive the data transmitted by the local communicating apparatus  10   b  before transmitting the data via the transmitting line of the remote transmission lines  1   a  in the additional transmission step. The local communicating apparatus  10   b  is operative to transmit the data via the intermediate line  3  after receiving the data transmitted by the targeted apparatus  30  via the receiving line of the local transmission lines  1   b.  The remote communicating apparatus  10   a  is operative to receive the data transmitted by the local communicating apparatus  10   b  before transmitting the data via the receiving line of the remote transmission lines  2   a.  The remote communicating apparatus  10   a  is operative to receive via the transmitting line of the remote transmission lines  1   a  the data transmitted by the remote controller  20   a  before transmitting the data via the intermediate line  3 , the local communicating apparatus  10   b  being operative to receive the data transmitted by the remote communicating apparatus  10   a  before transmitting via the transmitting line of the local transmission lines  2   b.    
     FIG. 3  is a block diagram of the controller  20  forming part of the remote control system according to the present invention. The controller  20  is shown in  FIG. 3  to comprise a console unit  204  for operating the targeted apparatus, a display unit  205  for displaying the information associated with the received data, a first receiving means  211  for receiving the data via the receiving line  1   b  and  2   a  (shown in  FIG. 1 ), a second receiving means  221  for receiving the data via the transmitting line  1   a  and  2   b  (shown in  FIG. 1 ), a transmitting means  212  for transmitting the data via the transmitting line, detecting means  213  for detecting the data transmitted via the second line, and a transmission controlling means  203  for controlling the transmitting means  212  in such a manner that the transmitting means  212  is selectively switched between under the operative state and the inoperative state based on the data detected by the detecting means  213 , The transmission controlling means  203  comprises a controlling means  214  for controlling the execution states of the transmitting means  212  after judging whether or not the data is detected by the detecting means  213 , a buffer memory  215  for buffering the data received by the first receiving means  211 , a buffer memory  216  for buffering the data received by the second receiving means  221 , a buffer memory  225  for buffering the data to be transmit via the transmitting line. 
     FIG. 4  shows a sequence diagram of the embodiment of the process of the remote control system according to the present invention. 
   The following description will now be directed to the process of the remote controller forming part of the remote control system according to the present invention with reference to  FIG. 4 . The data indicative of a “move first camera left” instruction, for example, is initially transmitted by the remote controller  20   a  via the transmitting line of the remote transmission lines  1   a  (S 301 ), the data indicative of the “move first camera left” instruction is then received by the first receiving means  211  via the transmitting line of the remote transmission lines  1   a  before transmitting the data indicative of the “move first camera left” instruction via the intermediate line  3  (S 302 ). The data indicative of the “move first camera left” instruction is then received by the interface means  101  via the intermediate line  3  before the data indicative of the “move first camera left” instruction is transmitted by the first transmitting means  112  via the transmitting line of the local transmission lines (S 303 ). The data indicative of the “move first camera left” instruction is finally received by the targeted apparatus  30  via the transmitting line of the local transmission lines before the targeted apparatus  30  has the first camera  31  move to the left (S 304 ). 
   Under the state above mentioned, the data indicative of an “alternative camera” instruction to be performed by the targeted apparatus  30  is initially transmitted by the local controller  20   b  via the transmitting line of the local transmission line (indicative of the second line of the local transmission line) (S 311 ), the second camera being then selected by the targeted apparatus after receiving the data indicative of the “alternative camera” instruction (S 312 ). The data indicative of an “alternative camera” instruction is then received by the second receiving means of the local communicating apparatus  10   b  via the transmission line of the local transmission lines (indicative of the second line of the local transmission lines) in the additional reception step (S 313 ) before transmitting the data indicative of an “alternative camera” instruction (S 314 ). The data indicative of an “alternative camera” instruction is received by the interface means of the remote communicating apparatus  10   a  via the intermediate line before the data indicative of an “alternative camera” instruction via the transmitting line of the remote transmission line (indicative of the first line of the remote transmission line) is transmitted by the second transmitting means in the additional transmission step (S 315 ). The data indicative of an “alternative camera” instruction is then received by the second receiving means of the remote communicating apparatus  20   a  via the transmitting line. From the foregoing description, it will be understood that the data indicative of an “alternative camera” instruction transmitted by the local controller  10   b  can be received and recognized as the control signal of the local controller  10   b  by the remote controller  10   a.  This leads to the fact that the data, for example, indicative of a “zooming second camera” instruction is transmitted by the remote controller  10   a  to the targeted apparatus  30  via the remote communicating apparatus  10   a  and local communicating apparatus  10   b  before the data indicative of a “zooming second camera” instruction is correctively performed by the targeted apparatus  30  (S 321 , S 322 , S 323 , S 324 ). 
     FIG. 5  shows a sequence diagram indicative of the process of the embodiment of the remote control system according to the present invention. 
   The following description will now be directed to the process of the remote control system according to the present invention with reference to  FIG. 5 . The intruder, for example, is initially detected by the detecting unit  32  before the “alarm” signal is outputted by the detecting unit  32  to the targeted apparatus  30  (S 401 ). The data indicative of the “alarm” information is then transmitted by the targeted apparatus  30  via the receiving line of the local transmission lines, (S 402 ). The data indicative of the “alarm” information is then received by the local communicating apparatus  10   b  via the receiving line of the local transmission lines before the data indicative of the “alarm” information is transmit by the interface means  101  of the local communicating apparatus  10   b  via the intermediate line (S 403 ). The data indicative of the “alarm” information is then received by the interface means  101  of the remote communicating apparatus 10 a via the intermediate line (S 404 ) before the data indicative of the “alarm” information is then received by the remote controller  20   a.    
   Under the state above mentioned, the data indicative of the “alarm” information is initially received by the local controller  20   b  via the receiving line of the local transmission line (S 405 ). The data indicative of the “cancel alarm” instruction to be performed by the targeted apparatus  30  is then transmitted by the local controller  20   b  via the receiving line of the local transmission line (indicative of the second line of the local transmission lines) (S 411 ), the data indicative of the “cancel alarm” instruction being then received by the targeted apparatus  30  via the transmitting line of the local transmission lines before the targeted apparatus  30  has survey unit  32  cancel the alarm. The data indicative of the “cancel alarm” instruction is then received by the second receiving means of the local communicating apparatus  20   b  via the transmitting line of the local transmission lines (indicative of the second line of the local transmission lines) (S 413 ), the data indicative of the “cancel alarm” instruction being then transmitted by the interface means  101  of the local communicating apparatus  20   b  via the intermediate line (S 414 ). The data indicative of the “cancel alarm” instruction is then received by the interface means  101  of the remote communicating apparatus  20   a  via the intermediate line before the data indicative of the “cancel alarm” instruction is then transmitted by the second transmitting means via the transmitting line of the remote transmission lines (indicative of the first line of the remote transmission lines) in the additional transmission step (S 415 ). The data indicative of the “cancel alarm” instruction is finally received by the second receiving means of the remote controller  20   a  via the transmitting line. From the foregoing description, it will be understood that the data indicative of the “cancel alarm ” instruction transmitted by the local controller  10   b  can be received and recognized as the control signal of the local controller  10   b  by the remote controller  10   a.    
     FIG. 6  is a flowchart of the process of the remote control system shown in  FIG. 2 . The following description will now be directed to the process of the remote control system according to the present invention with reference to  FIG. 6 . 
   The data indicative of the “alternative camera” instruction (referred to simply as “control data”) is initially transmitted by the local controller  10   b  via the transmitting line before the control signal is received by the second receiving means  121  of the local communicating apparatus  20   b  via transmitting line (indicative of the second line of the local transmission line) in the additional reception-step (S 501 ). The control data received by the second receiving means  121  is then buffered by the buffer memory  125  (S 502 ). The control data buffered by the buffer memory  125  is then transmitted by the interfacing circuit  101  via the intermediate line (S 503 ), wherein the control data including information in which the control data is indicative of the additional data (i.e. the control data is received via the second line), the control data being received by the remote controller  20   a.    
   The control data is then received by the interface means  101  of the remote communicating apparatus  10   a  (S 504 ) before the control data is recognized by the interface means as the additional data. The control data received by the interfacing circuit  101  is then buffered by the second buffer memory  126  (S 505 ). The control data received by the first receiving means  111  via the transmitting line of the remote transmission line is then detected by the first detecting means  113  (S 506 ). (i.e. the control data is detected.) Here, the detecting means  123  allow the controlling means  124  to control the first transmitting means  122  not to transmit the control data in the disable step (S 507 ) after the judgment is made by the detecting means  113  on whether as the control data received by the first receiving means  111  via the transmitting line of the remote transmission line is received by the first receiving means  111 . The detecting means  123 , on the other hand, allow the controlling means  124  to control the first transmitting means  122  to transmit the control data in the enable step (S 508 ) after the judgment is made by the detecting means  113  on whether as the control data received by the first receiving means  111  via the transmitting line of the remote transmission line is not received by the first receiving means  111 . The control data transmitted by the local controller  20   b  to the targeted apparatus  30  is received by the remote controller  20   a  via transmitting line after the control data is transmitted by the second transmitting means  122  transmitting line in the additional transmission step (S 509 ). From the above detailed description, it will be understood that the data indicative of the “alternative camera” instruction transmitted by the local controller  20   b  can be received and recognized as the control data by the remote controller  20   a.    
   From the above detailed description of the embodiment of the remote control system, it will be understood that the control data transmitted by the local controller to the targeted apparatus can be received by the remote controller due to the fact that the remote controller is adapted to receive the control data transmitted by the remote communicating apparatus via transmitting line after the control data transmitted by the local controller to the targeted apparatus is received by the local communicating apparatus to have the local communicating apparatus transmit to the remote communicating apparatus via the intermediate line, this leading to the fact that the targeted apparatus is controlled by each of the controllers in remote areas. 
   Although the previously mentioned embodiment as shown in  FIG. 1  has been described with only one targeted apparatus connected to the local communicating apparatus via the local transmission lines, two targeted apparatuses may be respectively connected to the local communicating apparatus and the remote communicating apparatus to allow each of the local communicating apparatus and the remote communicating apparatus to control each of two targeted apparatus to achieve the advantage of the remote control system according to the present invention. 
   In the above embodiment, the remote communicating apparatus connected to the remote controller is provided in only one remote area to allow the remote controller to control the targeted apparatus, however, there may be a plurality of remote communicating apparatuses respectively connected to the remote controllers respectively provided in plurality of remote areas to allow each of the remote controllers to control the targeted apparatus to achieve the advantage of the remote control system according to the present invention. 
   While there has been described in the forgoing embodiment about the fact that the multiplexing/demultiplexing means forming one of the remote and local communicating apparatus is operative to extract the control data from the data transmitted additionally by the other of the remote and local communicating apparatus to transmit only control data via the transmission lines, the control data received by one of the remote and local communicating apparatus may not be extracted by the multiplexing and demultiplexing means, but may be still remained in the data transmitted by the other of the remote and local communicating apparatus to achieve the advantage of the remote control system according to the present invention. With the control data extracted by one of the remote and local communicating apparatus, the control data may be transmitted to the other of the remote and local communicating apparatus to achieve the advantage of the remote control system according to the present invention. 
   As will be seen from the foregoing description, the communicating apparatus and the remote control system according to the present invention can provide a communicating apparatus and a remote control system which can allow the controller provided in each of the remote areas to control the targeted apparatus.