Abstract:
A communication system includes a data processing device that communicates with a communication device via a first transmission link. The communication device includes a first communication controller that controls communication with the data processing device via the first transmission link, and a second communication controller that controls communication via a second transmission link which is different from the first transmission link. The communication device also includes a transmitter that transmits transmission data sent via the first transmission link through the second transmission link, a canceller that cancels transmission of the transmission data through the second transmission link upon receiving a canceling command via the first transmission link, and an observer that observes whether the communication via the first transmission link, which transmits the transmission data to the communication device, is enabled, in response to receiving the transmission data via the first transmission link.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to Japanese Patent Application No. 2009-178695, filed on Jul. 31, 2009, the entire subject matter and disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    1. Field of the Disclosure 
         [0003]    The features herein relate to a communication device and a communication system. 
         [0004]    2. Description of the Related Art 
         [0005]    A known communication system includes a data processing device having a reading function and a communication device having a facsimile transmission function. The communication system works in such a way that the data processing device reads image data and transmits the image data to the communication device as transmission data, and that the communication device transmits the received transmission data to an opposite device through a telephone network by facsimile. 
         [0006]    A known facsimile device is provided with a key, e.g., a button, for canceling facsimile transmission in some cases. For example, a user may become aware of an error in a document or an address in some cases after the user inputs an order to start facsimile transmission and the facsimile device starts reading the document put on a document tray. 
       SUMMARY OF THE DISCLOSURE 
       [0007]    An embodiment of the invention comprises a communication device and a communication system which can advantageously prevent transmission of transmission data, which the user requests to be canceled, from being inconveniently carried out. 
         [0008]    In an embodiment of the invention, a communication device is configured to form a first transmission link with a data processing device configured to output transmission data. The communication device comprises a first communication controller configured to control a communication with the data processing device via the first transmission link, a second communication controller configured to control a communication via a second transmission link which is different from the first transmission link, a transmitter configured to transmit the transmission data sent via the first transmission link through the second transmission link, a particular canceller configured to cancel the transmission of the transmission data through the second transmission link upon receiving a canceling command sent via the first transmission link, and an observer configured to observe whether the communication via the first transmission link, which transmits the transmission data to the communication device, is enabled, in response to receiving the transmission data via the first transmission link. 
         [0009]    In another embodiment of the invention, a communication system comprises a data processing device configured to output transmission data. The data processing device comprises a cancel command outputter configured to output a canceling command. The communication system also comprises a communication device comprising a first communication controller configured to control a communication with the data processing device via a first transmission link, a second communication controller configured to control a communication via a second transmission link which is different from the first transmission link, a transmitter configured to transmit the transmission data sent via the first transmission link through the second transmission link, a particular canceller configured to cancel the transmission of the transmission data through the second transmission link upon receiving the cancelling command outputted from the data processing device, and an observer configured to observe whether the communication via the first transmission link is enabled, in response to receiving the transmission data via the first transmission link. 
         [0010]    Other objects, features, and advantages of embodiments of the present invention will be apparent to persons of ordinary skill in the art from the following description of embodiments with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a block diagram for illustrating an electric configuration of a communication system including a BOX, an MFP, and an access point, according to an embodiment of the invention. 
           [0012]      FIG. 2  schematically illustrates an exemplary sequence of a facsimile transmission data transmission process carried out by the BOX, according to an embodiment of the invention. 
           [0013]      FIGS. 3A and 3B  are flowcharts for illustrating a facsimile mode process carried out by a CPU of the MFP, according to an embodiment of the invention. 
           [0014]      FIGS. 4A and 4B  are flowcharts for illustrating the facsimile transmission data transmission process carried out by a CPU of the BOX, according to an embodiment of the invention. 
           [0015]      FIGS. 5A and 5B  are flowcharts for illustrating a continuation of the facsimile transmission data transmission process shown in  FIG. 4B . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0016]    Various embodiments of the invention, and their features and advantages, will be explained with reference to the  FIGS. 1-5B , like numerals being used for corresponding parts in the various drawings.  FIG. 1  is a block diagram for illustrating an electric configuration of a communication system  1  including a circuit control device (hereafter interchangeably referred to as the “BOX”)  10 , a multifunction peripheral device (hereafter interchangeably referred to as the “MFP”)  30  and an access point (hereafter interchangeably referred to as the “AP”)  51 . 
         [0017]    The MFP  30  may produce facsimile transmission data with a specified address, and may provide the BOX  10  with the produced data. Meanwhile, upon receiving the facsimile transmission data from the MFP  30 , the BOX  10  may transmit the transmission data to the specified address via a telephone network  100 . In an embodiment of the invention, the BOX  10  and the MFP  30  are formed separately in the communication system  1 , and those devices are connected to each other by wireless or wired. Thus, the MFP  30  may not be connected directly to the telephone network  100  and may thereby be put at any preferred position. 
         [0018]    The MFP  30  may be provided with a transmission canceling key  37   b  for allowing a user to cancel the transmission of the facsimile transmission data. If the user operates the transmission canceling key  37   b , the MFP  30  may output a transmission canceling command. Upon receiving the transmission canceling command, the BOX  10  may cancel the transmission of the facsimile transmission data. 
         [0019]    If, however, the communication between the BOX  10  and the MFP  30  is disabled, and the MFP  30  outputs a transmission canceling command in the meantime, the BOX  10  does not receive the transmission canceling command. In an embodiment of the invention, even in such a case, the communication system  1  and the BOX  10  of the embodiment may prevent the transmission of the facsimile transmission data to be canceled, as described in detail as follows. 
         [0020]    The BOX  10  may include a CPU  11 , a ROM  12 , a RAM  13 , a flash memory  14 , a wireless LAN communication control circuit  15 , an operation key  17 , an LCD  18 , a modem  19  and an NCU (“Network Control Unit”)  20 . The CPU  11 , the ROM  12 , the RAM  13  and the flash memory  14  may be connected to one another, e.g., via a bus line  21 . Further, the wireless LAN communication control circuit  15 , the operation key  17 , the LCD  18 , the modem  19 , the NCU  20  and the bus line  21  may be connected to one another via an input/output port  22 . 
         [0021]    The CPU  11  may control each of the units connected with the input/output port  22  in accordance with a fixed value or a program stored in the ROM  12 , etc. or various signals exchanged via a transmission line  200 . The ROM  12  may be a non-rewritable memory in which a program for carrying out a process described later, e.g., as described with reference to  FIGS. 4A ,  4 B,  5 A, and  5 B, etc. is stored. 
         [0022]    The RAM  13  may be a rewritable volatile memory, and may include a connection checkless flag  13   a , a first timer  13   b  and a second timer  13   c . If the connection checkless flag  13   a  is “0”, the BOX  10  may transmit a connection check command to the MFP  30 . If the connection checkless flag  13   a  is “1”, the BOX  10  does not transmit a connection check command to the MFP  30 . The connection check command will be described in more detail later, with reference to  FIG. 2 . The first timer  13   b  may be a timer which counts a lapse of time since the connection check command is transmitted. The second timer  13   c  is a timer which may be used for periodic transmission of the connection check command. The flash memory  14  may be a rewritable non-volatile memory. 
         [0023]    The wireless LAN communication control circuit  15  may form the transmission lines  200  with the MFP  30  and the AP S 1 , and may control wireless communication of a wireless LAN system over the transmission lines  200 . The wireless LAN system described here is, e.g., a communication system defined by the specifications of IEEE 802.11a/b/g. 
         [0024]    The LCD  18  may display a menu, an operation procedure, a state of a process being carried out, information corresponding to a press of the operation key  17 , etc. The modem  19  may modulate facsimile transmission data sent from the MFP  30  to a signal which may be transmitted through the telephone network  100 , and may transmit the signal via the NCU  20 . The modem  19  also may receive and demodulate a signal sent from the telephone network  100  via the NCU  20 . The NCU  20  may control communication through the telephone network  100 . 
         [0025]    The MFP  30  may include a CPU  31 , a ROM  32 , a RAM  33 , a flash memory  34 , a wireless LAN communication control circuit  35 , operation keys  37 , an LCD  38 , a printer  39  and a scanner  40 . 
         [0026]    The CPU  31 , the ROM  32 , the RAM  33  and the flash memory  34  may be connected to one another, e.g., via a bus line  43 . Further, the wireless LAN communication control circuit  35 , the operation keys  37 , the LCD  38 , the printer  39 , the scanner  40 , a power supply circuit  41  and the bus line  43  may be connected to one another via an input/output port  44 . 
         [0027]    The CPU  31  may control each of functions and each of the units connected with the input/output port  44  in accordance with a fixed value or a program stored in the ROM  32 , etc. or various signals exchanged via the wireless LAN communication control circuit  35 . 
         [0028]    The ROM  32  may be a non-rewritable memory in which a control program run by the MFP  30 , etc. is stored. Respective programs for carrying out a facsimile mode process, which is described in detail later with reference to  FIGS. 3A and 3B , may be stored in the ROM  32 . The RAM  33  and the flash memory  34  may be a rewritable volatile memory and a rewritable non-volatile memory, respectively. The wireless LAN communication control circuit  35  may be configured similarly as the wireless LAN communication control circuit  15 , and its explanation is omitted. 
         [0029]    The operation keys  37  include a power key  37   a  that a user may operate to power on and off the MFP  30 , and a transmission canceling key  37   b . The CPU  31  may control power supply and a cut-off from the power supply circuit  41  to each of the units in accordance with operations on the power key  37   a.    
         [0030]    The power supply circuit  41  may be a power supply circuit which converts AC voltage  60  supplied by a commercial power source connected via a power plug (not shown) into DC voltage, and supplies each of the units of the MFP  30  with the DC voltage. A permanent connection line (not shown in  FIG. 1 ) may be positioned between the power supply circuit  41  and the CPU  31  for supplying power from the power supply circuit  41  to the CPU  31  at all times. 
         [0031]    A power supply line (not shown) may be positioned between each of the units, except for the CPU  31  and the power supply circuit  41 , for supplying power from the power supply circuit  41  to each of the units. A switch (not shown) may be provided between the power supply circuit  41  and the CPU  31  for switching the power-on and off from the power supply circuit  41  to each of the units. 
         [0032]    If the user operates the power key  37   a  in a powered-off state in which each of the units except for the CPU  31  is not supplied with power, the CPU  31  may turn on the switch (not shown), so as to shift the MFP  30  to a powered-on state, in which each of the units is supplied with power by power supply circuit  41 . Meanwhile, if the user operates the power key  37   a  in the powered-on state, the CPU  31  may cut off the power supplied from the power supply circuit  41  to each of the units except for the CPU  31  by turning the switch off, so as to shift the MFP  30  to the powered-off state. 
         [0033]    If the transmission canceling key  37   b  is operated, the MFP  30  outputs a transmission canceling command to the BOX  10 . The transmission canceling command will be described later in more detail with reference to  FIG. 2 . 
         [0034]    The LCD  38 , the printer  39  and the scanner  40  may include a known LCD, a known printer and a known scanner, and their explanations are omitted. The MFP  30  produces facsimile transmission data on the basis of a document that the scanner  40  reads, and outputs the facsimile transmission data to the transmission line  200 . 
         [0035]      FIG. 2  schematically illustrates an exemplary sequence of a facsimile transmission data transmission process carried out by the BOX  10 , according to an embodiment of the invention. In an embodiment of the invention, among data communication events shown in  FIG. 2 , every event concerning the communication between the BOX  10  and the MFP  30  may be carried out via the transmission line  200 . 
         [0036]    To begin with, the MFP  30  may read a document by using the scanner  40 , and may produce facsimile transmission data. Further, a facsimile number of an opposite device that a user inputs to the MFP  30  may be specified as an address of the facsimile transmission data. 
         [0037]    Then, the MFP  30  may transmit a facsimile data transfer request to the BOX  10  via the transmission line  200  [ 1 ]. Upon receiving the facsimile data transfer request, the BOX  10  may transmit an ACK command to the MFP  30  [ 3 ]. 
         [0038]    Then, the MFP  30  may output the facsimile transmission data with the specified address [ 5 ]. After receiving the facsimile transmission data, the BOX  10  first may output an ACK command [ 6 ] and next may output a connection check command to the MFP  30 , i.e., the sender of the facsimile transmission data [ 7 ]. If the MFP  30  reads a plurality of pages of the document and transmits the facsimile transmission data of the plural pages to the BOX  10 , the BOX  10  may output an ACK command and a connection check command after receiving the facsimile transmission data of all the pages. 
         [0039]    Upon receiving the connection check command, the MFP  30  may transmit an ACK command to the BOX  10  [ 9 ]. Upon receiving the ACK command from the MFP  30 , the BOX  10  may detect a state in which the communication with the MFP  30  is being enabled via the transmission line  200 . As described above, the BOX  10  may observe whether the communication with the MFP  30  is being enabled via the transmission line  200 , depending upon whether the MFP  30  replies to the connection check command. 
         [0040]    Upon receiving the ACK command, the BOX  10  connects, e.g., makes a call, to the address specified for the facsimile transmission data received from the MFP  30  [ 11 ], and transmits the facsimile transmission data on a frame-by-frame basis via communication through the telephone network  100  [ 13 ]. 
         [0041]    As described above, after receiving the facsimile transmission data of all the pages, the BOX  10  may start to transmit the facsimile transmission data to the telephone network  100 . 
         [0042]    Then, after starting to transmit the facsimile transmission data, the BOX  10  may output a connection check command to the MFP  30 , i.e., the sender of the facsimile transmission data [ 7 ]. Upon receiving the connection check command, the MFP  30  may transmit an ACK command to the BOX  10  [ 9 ]. That is, the BOX  10  may observe the wireless communication with the MFP  30  via the transmission line  200  also while transmitting the facsimile transmission data. 
         [0043]    If the user operates the transmission canceling key  37   b , e.g., as shown in  FIG. 1 , the MFP  30  may transmit a transmission canceling command to the BOX  10 , although this transmission is not shown in  FIG. 2 . Upon receiving the transmission canceling command, the BOX  10  cancels the transmission of the facsimile transmission data. Thus, upon becoming aware of an error in the address or in the document, the user may cancel the transmission of the facsimile transmission data addressed to an undesirable addressee or the transmission of the facsimile transmission data itself by operating the transmission canceling key  37   b  of the MFP  30 . 
         [0044]    When BOX  10  does not receive the transmission canceling command, the BOX  10  may continue to transmit the facsimile transmission data and to observe the wireless communication via the transmission line  200 . The first timer  13   b  may count a lapse of time starting from when BOX  10  transmits the connection check command. When BOX  10  does not receive the ACK command after the first timer  13   b  reaches a timeout after the connection check command is output while the process is being repeated, the BOX  10  may detects the communication with the MFP  30  via the transmission line  200  as being disabled because no ACK command has been received before first timer  13   b  reaches the timeout. 
         [0045]    In this case, the BOX  10  may transmit a disconnection signal, e.g., a cut-off signal, to the telephone network  100  and may disconnect a connection with an exchange (not shown) of the telephone network  100 , so as to cancel the transmission of the facsimile transmission data [ 15 ]. 
         [0046]    Thus, even if the BOX  10  cannot receive the transmission canceling command output from the MFP  30  because the wireless communication with the MFP  30  via the transmission line  200  has been disabled, the BOX  10  may cancel the transmission of the facsimile transmission data via the above process. As a result, the transmission of the facsimile transmission data which should be canceled may be prevented from being inconveniently carried out. 
         [0047]      FIGS. 3A and 3B  are flowcharts for illustrating a facsimile mode process carried out by the CPU  31  of the MFP  30 , according to an embodiment of the invention. The facsimile mode process may be carried out while the MFP  30  is set in the facsimile mode. 
         [0048]    To begin with, at Step S 302 , the CPU  31  may identify whether an operation for facsimile transmission is executed. According to an embodiment, if a user operates a transmission key (not shown) after setting a document at a proper position and inputting a facsimile number of an addressee&#39;s opposite device, the CPU  31  may identify an operation for facsimile transmission as having been executed. In another embodiment of the invention, the user may perform a different operation in order to execute an operation for facsimile transmission. 
         [0049]    If the identification of Step S 302  is affirmative, e.g., “YES” at Step S 302 , then at Step S 304 , the CPU  31  may display a disabled connection process check message, e.g., “transmit fax even if MFP and BOX cannot be connected?” on the LCD  38 . If the user operates for facsimile transmission after strictly checking the address and the document for an error, the user then may rarely operate the transmission canceling key  37   b  thereafter. Thus, it may be desirable to transmit the facsimile transmission data even if the wireless communication between the BOX  10  and the MFP  30  becomes disconnected. 
         [0050]    Thus, according to an embodiment, the MFP  30  may inquire about the process in case of disabled communication between the MFP  30  and the BOX  10  before the output of the facsimile transmission data. 
         [0051]    Then, at Step S 306 , the CPU  31  may identify whether the user chooses “transmit” in response to the disabled connection process check message displayed on the LCD  38 . If the identification of Step S 306  is affirmative, e.g., “YES” at Step S 306 , then at Step S 308 , the CPU  31  may set a connection checkless attribute, i.e., a command indicating whether there is a need to observe the wireless communication via the transmission line  200 , to “1”. The connection checkless attribute “1” may be a command which indicates that it is unnecessary to observe the wireless communication via the transmission line  200 . Upon receiving the connection checkless attribute “1”, the BOX  10  may not observe the wireless communication via the transmission line  200 . 
         [0052]    Meanwhile, if the identification of S 306  is negative, e.g. “NO” at Step S 306 , then at Step S 310 , the CPU  31  sets the connection checkless attribute to “0”. The connection checkless attribute “0” may be a command which indicates that it is necessary to observe the wireless communication via the transmission line  200 . Upon receiving the connection checkless attribute “0”, the BOX  10  may observe the wireless communication via the transmission line  200 . 
         [0053]    Then, at Step S 312 , the CPU  31  may read all pages of a document set at a proper position by using the scanner  40 , and at Step S 313 , the CPU  31  may produce facsimile transmission data and may store the facsimile transmission data in the RAM  33 . Then, at Step S 314 , the CPU  31  may transmit a facsimile transmission data transfer request command to the BOX  10 , and, at Step S 316 , may wait for an ACK command to be received. 
         [0054]    Upon receiving the ACK command, e.g., “YES” at Step S 316 , the CPU  31  may output the facsimile transmission data including the connection checkless attribute, and at Step S 318 , the CPU  31  may transmit the facsimile transmission data to the BOX  10  via the transmission line  200 . Because the CPU  31  transmits the connection checkless attribute in relation to the facsimile transmission data, the BOX  10  may control every unit of the facsimile transmission data as to whether the wireless communication via the transmission line  200  is observed, which is convenient for the user to use. 
         [0055]    Then, at Step S 320 , the CPU  31  may wait for an ACK command to be received. Upon receiving the ACK command, e.g., “YES” at Step S 320 , the CPU  31  may return to Step S 302 . 
         [0056]    If the identification of Step S 302  is negative, e.g., “NO” at Step S 302 , then at Step S 322 , CPU  31  may identify whether the CPU  31  has received a connection check command. Thus, because the BOX  10  transmits a connection check command to the MFP  30  as described above, CPU  31  determines whether the CPU  31  has received a connection check command, so that BOX  10  may observe whether the wireless communication is being enabled via the transmission line  200 . 
         [0057]    If the identification of Step S 322  is affirmative, e.g., “YES” at Step S 322 , then at Step S 324 , the MFP  30  may transmit an ACK command to the BOX  10 , and then CPU  31  may return to Step S 302 . The BOX  10  thereby may detect a state in which the communication with the MFP  30  is enabled via the transmission line  200 . 
         [0058]    Meanwhile, if the identification of Step S 322  is negative, e.g., “NO” at Step S 322 , then at Step S 326 , the CPU  31  may identify whether the transmission canceling key  37   b  has been operated. If the identification of Step S 326  is affirmative, e.g., “YES” at Step S 326 , then at Step S 328 , the CPU  31  may output a transmission canceling command and may transmit the transmission canceling command to the BOX  10 . Then, at Step S 330 , the CPU  31  may wait for an ACK command to be received. Upon receiving the ACK command, e.g., “YES” at Step S 330 , then the CPU  31  may return to Step S 302 . 
         [0059]    If the identification of Step S 326  is negative, e.g., “NO” at Step S 326 , then at Step S 332 , the CPU  31  may identify whether an operation to power on the MFP  30  is executed. Specifically, the CPU  31  may identify whether an operation to press the power key  37   a  while the MFP  30  is in a powered off state, in which only the CPU  31  may be supplied with power. If the identification of Step S 332  is affirmative, e.g., “YES” at Step S 332 , then at Step S 334 , the CPU  31  may transmit a power-on command to the BOX  10 . 
         [0060]    The power-on command transmitted to the BOX  10  may indicate that the operation to power on the MFP  30  is executed. Then, at Step S 330 , the CPU  31  may wait for an ACK command to be received. Meanwhile, if the identification of Step S 332  is negative, e.g. “NO” at Step S 322 , then at Step S 336 , the CPU  31  may identify whether an operation to power off the MFP  30  is executed. Specifically, the CPU  31  may identify whether an operation to press the power key  37   a  while the MFP  30  is in a powered on state has been executed. If the identification of Step S 336  is negative, e.g., “NO” at Step S 336 , then the CPU  31  returns to Step S 302  and repeats the process. 
         [0061]    Meanwhile, if the identification of Step S 336  is affirmative, e.g., “YES” at Step S 336 , then at Step S 338 , the CPU  31  may transmit a power-off command to the BOX  10 . The power-off command transmitted to the BOX  10  may indicate that the operation to power off the MFP  30  is executed. Then, at Step S 339 , the CPU  31  may cut off the power supply from the power supply circuit  41  to each of the units, except for the CPU  31 . Thus, the MFP  30  thereby may be set in the powered off state, in which only the CPU  31  is supplied with power, and the CPU  31  may return to Step S 302 . 
         [0062]    Upon receiving the power-off command from the MFP  30 , the BOX  10  may set the connection checkless flag  13   a  to “1”. Then, if the connection checkless flag  13   a  is “1”, the BOX  10  may not observe the wireless communication via the transmission line  200 . That is, if the power key  37   a  of the MFP  30  is operated so that the MFP  30  is powered off, the BOX  10  may interrupt the observation of the wireless communication. Even if the wireless communication via the transmission line  200  is disconnected, the BOX  10  may not cancel the transmission of the facsimile transmission data. 
         [0063]    If the MFP  30  is forcibly powered off, e.g., because a power plug is pulled from an outlet, or because of loss of power to the outlet, but not because the power key  37   a  is operated, then neither the power supply circuit  41  nor the CPU  31 , e.g., as shown in  FIG. 2 , is supplied with power. The MFP  30  thereby may finish the facsimile mode process without issuing a power-off command. As a result, the BOX  10  may continue to observe the wireless communication via the transmission line  200 , and may cancel the transmission of the facsimile transmission data if the wireless communication is disconnected. 
         [0064]      FIGS. 4  A,  4 B,  5 A and  5 B are flowcharts for illustrating the facsimile transmission data transmission process carried out by the CPU  11  of the BOX  10 , according to an embodiment of the invention. The facsimile transmission data transmission process may be carried out at regular intervals while the BOX  10  is being powered on. The BOX  10  transmits facsimile transmission data sent from the MFP  30  to a specified address via the telephone network  100 . Even while carrying out the facsimile transmission data transmission process, the CPU  11  may set the connection checkless flag  13   a  to “1” and “0” by carrying out an interrupt process upon receiving a power-on command and a power-off command from the MFP  30 , respectively (not shown). 
         [0065]    To begin with, at Step S 402 , the CPU  11  may identify whether a facsimile transmission data transfer request command is received from the MFP  30 . If the identification of Step S 402  is negative, e.g., “NO” at Step S 402 , then, the CPU  11  ends the process. 
         [0066]    Meanwhile, if the identification of Step S 402  is affirmative, e.g., “YES” at Step S 402 , then at Step S 404 , the CPU  11  may transmit an ACK command to the sender of the facsimile transmission data transfer request command. Then, at Step S 406 , the CPU  11  may suspend the process until facsimile transmission data is sent from the sender of the facsimile transmission data transfer request command. If the facsimile transmission data is provided, the identification of Step S 406  turns affirmative, e.g. “YES” at Step S 406 . Then, at Step S 408 , the CPU  11  may transmit an ACK command to the MFP  30 , i.e., the sender of the facsimile transmission data. 
         [0067]    Then, at Step S 410 , the CPU  11  may identify whether the connection checkless attribute included in the facsimile transmission data received at Step S 406  is “1”. If the connection checkless attribute included in the facsimile transmission data received at Step S 406  is “1”, e.g. “YES” at Step S 410 , then the CPU  11  skips Steps S 412 -S 425  for observing the wireless communication via the transmission line  200 , and shifts to Step S 426 . That is, if the connection checkless attribute provided in relation to the facsimile transmission data is “1” indicating that the communication need not to be observed, the CPU  11  may not observe the communication for identifying whether the transmission of the facsimile transmission data needs to be canceled. 
         [0068]    If the user does not intend to cancel the transmission of the facsimile transmission data, no connection checkless command for observing the communication may be transmitted and no ACK command is received, and communication traffic on the transmission line  200  can thereby be reduced. Further, even if the communication between the BOX  10  and the MFP  30  is disabled, the facsimile transmission data may be transmitted to the addressee. 
         [0069]    Meanwhile, if the connection checkless attribute is “0”, i.e., the connection checkless attribute indicates that the wireless communication via the transmission line  200  needs to be observed, the identification of Step S 410  may turn negative, e.g., “NO” at Step S 410 . In this case, at Step S 412 , the CPU  11  may identify whether the connection checkless flag  13   a  is “1”. 
         [0070]    The process will be explained first in an assumption that the connection checkless flag is not “1”. Specifically, when the identification of Step S 412  is negative in this case, e.g. “NO” at Step S 412 , then at Step S 414 , the CPU  11  then may transmit a connection check command to the MFP  30 , i.e., the sender of the facsimile transmission data. Then, at Step S 416 , the CPU  11  may start the first timer  13   b , and at Step S 418 , may identify whether an ACK command is received. That is, the CPU  11  observes whether the wireless communication is enabled via the transmission line  200 . 
         [0071]    If the identification of Step S 418  is negative, e.g. “NO” at Step S 418 , then at Step S 420 , the CPU  11  may identify whether the first timer  13   b  has reached a timeout. While the identification of S 420  is negative, e.g. “NO” at Step S 420 , the CPU  11  may return to Step S 418 . Upon receiving an ACK command, e.g., “YES” at Step S 418  while repeating the process in such a way, then at Step S 426 , the CPU  11  then may identify whether the CPU  11  has received a transmission canceling command transmitted from the MFP  30 , i.e., the sender of the facsimile transmission data, via the transmission line  200 . 
         [0072]    If the identification of Step S 426  is affirmative, e.g. “YES” at Step S 426 , then the CPU  11  may end the facsimile transmission data transmission process. That is, upon receiving the transmission canceling command output from the MFP  30  via the transmission line  200 , the CPU  11  may cancel the transmission of the facsimile transmission data. If the identification of Step S 426  is negative, e.g., “NO” at Step S 426 , then the CPU  11  may shift to Step S 427  shown in  FIG. 5A  and may start to transmit the facsimile transmission data. 
         [0073]    Meanwhile, upon receiving no ACK command, e.g. “NO” at Step S 418 , and identifying the first timer  13   b  as having reached a timeout, e.g., “YES” at Step S 420 , then the CPU  11  may detect that the wireless communication with the MFP  30  via the transmission line  200  is disabled on the basis that the CPU  11  has not received an ACK command in a given period of time. If that is the case, then at Step S 422 , the CPU  11  may display on the LCD  18  a transmission confirming message such as “Communication with MFP is disabled. Do you start facsimile transmission?”. 
         [0074]    Then, at Step S 424 , the CPU  11  may identify whether the user has chosen “transmit” in response to the transmission confirming message displayed on the LCD  18 . Specifically, the CPU  11  may identify whether the user has chosen to transmit the facsimile transmission data by operating the operation key  17  provided to the BOX  10 , regardless of the communication between the BOX  10  and the MFP  30  being disabled. 
         [0075]    If the identification of Step S 424  is negative, or “transmit” was not chosen in a given period of time, e.g. “NO” at Step S 424 , or a timeout with no selection, then the CPU  11  ends the facsimile transmission data transmission process. The transmission of the facsimile transmission data thereby may be canceled. 
         [0076]    Meanwhile, if the identification of Step S 424  is affirmative, e.g. “YES” at Step S 424 , then at Step S 425 , the CPU  11  may set the connection checkless flag  13   a  to “1”, and then may shift to Step S 427 , shown in  FIG. 5A . When the connection checkless flag  13   a  is set to “1”, the BOX  10  may not observe the wireless communication via the transmission line  200  while transmitting the facsimile transmission data in the following process. 
         [0077]    Upon receiving a power-on command from the MFP  30 , the BOX  10  may set the connection checkless flag  13   a  to “0”. Similarly, upon receiving a power-off command sent from the MFP  30 , as described above, the BOX  10  may set the connection checkless flag  13   a  to “1”. If “transmit” is chosen at Step S 425 , the BOX  10  also may set the connection checkless flag  13   a  to “1”. 
         [0078]    If the connection checkless flag  13   a  is set to “1”, the identification of Step S 412  may turn affirmative, and the CPU  11  thereby may skip Steps S 414 -S 425 , so as to stop observing the wireless communication with the MFP  30  via the transmission line  200 . 
         [0079]    That is, if the MFP  30  sends the power-off command to the BOX  10 , the BOX  10  may not cancel the transmission of the facsimile transmission data, even regardless of the wireless communication with the MFP  30  being disabled, because the MFP  30  does not output a transmission canceling command while the MFP  30  is being powered off. In other words, the BOX  10  may cancel the transmission of the facsimile transmission data if the BOX  10  cannot receive a transmission canceling command although the MFP  30  is powered on because the wireless communication with the MFP  30  via the transmission line  200  is disabled. 
         [0080]    When operating the MFP  30  according to an embodiment of the invention, a user may disconnect the power plug from the outlet to power off the MFP  30  in some cases. In particular, a user may become aware of an error in the address or the document and may want to cancel the transmission of the facsimile transmission data after the scanner  40  of the MFP  30  finishes reading the document, and the user could be confused in some cases. Such a user could suddenly disconnect the power plug from the outlet, if the user forgets about or is unaware of the transmission canceling key  37   b  provided to the MFP  30 . 
         [0081]    In such a case, the power supplied to the CPU  31  of the MFP  30  is cut off, and the MFP  30  may be powered off without outputting a power-off command. As a result, the BOX  10  of the embodiment may not receive a power-off command from the MFP  30 . Thus, the BOX  10  may keep the connection checkless flag  13   a  at “0” and may continue to observe the wireless communication with the MFP  30  via the transmission line  200 . Thus, because the wireless communication with the MFP  30  is disabled, the BOX  10  may cancel the transmission of the facsimile transmission data. 
         [0082]    Further, if a power-on command is sent from the MFP  30  while the transmission line  200  is not being observed as the connection checkless flag  13   a  is “1”, the BOX  10  may set the connection checkless flag  13   a  to “0”. The identification of Step S 412  thereby turns negative, e.g., “NO” at Step S 412 . Thus, after that, the BOX  10  may again start to observe the wireless communication via the transmission line  200 . Thus, if the MFP  30  is powered off once and an operation to power on the MFP  30  again is executed, the MFP  30  may possibly provide the BOX  10  with a transmission canceling command afterward the MFP is powered on again. That may occur in a case where, e.g., the user powers off the MFP  30  after finishing a process for outputting facsimile transmission data, and then becomes aware of an error in the address or the document, powers on the MFP  30  while being confused and operates the MFP  30  to cancel the transmission of the facsimile transmission data. Even in such a case, the transmission of the facsimile transmission data may be certainly canceled according to the facsimile transmission data transmission process of an embodiment of the invention. 
         [0083]    The BOX  10  may observe the wireless communication with the MFP  30  via the transmission line  200 , as previously explained. Upon detecting the communication between the BOX  10  and the MFP  30  becoming disabled, the BOX  10  may cancel the transmission of the facsimile transmission data, thereby preventing the facsimile transmission data from being transmitted. This may reduce a processing load of the data communication through the telephone network  100 . 
         [0084]    Further, if the BOX  10  is set not to immediately transmit facsimile transmission data received from the MFP  30 , e.g., to transmit the transmission data at a specified date and time as reserved transmission, the communication with the MFP  30  possibly may be disabled while waiting to transmit the facsimile transmission data in some cases. If a transmission canceling command is sent from the MFP  30  while the communication with the MFP  30  is disabled, the BOX  10  may not receive the transmission canceling command. The BOX  10  according to an embodiment, however, may cancel the transmission of the facsimile transmission data even in a case described above where the BOX  10  waits to transmit the facsimile transmission data for a period of time after receiving the facsimile transmission data. 
         [0085]      FIGS. 5A and 5B  are flowcharts for illustrating a continuation of the facsimile transmission data transmission process shown in  FIG. 4B . At Step S 427 , the CPU  11  may make a call to a specified address of the facsimile transmission data, so as, at Step S 428 , to start to transmit the facsimile transmission data. After that, the CPU  11  may transmit the facsimile transmission data on a frame-by-frame basis until finishing the facsimile transmission data transmission process. 
         [0086]    The BOX  10  may continue to observe the wireless communication via the transmission line  200  after starting to transmit the facsimile transmission data. Specifically, after Step S 428 , starting to transmit the facsimile transmission data, then at Step S 430 , the CPU  11  identifies whether the connection checkless attribute included in the facsimile transmission data received at Step S 406  is “1”. If the identification of Step S 430  is affirmative, e.g. “YES” at Step S 430 , then the CPU  11  skips Steps S 432 -S 444 . That is, the BOX  10  may not observe the communication for identifying whether the transmission of the facsimile transmission data needs to be canceled. 
         [0087]    Meanwhile, if the identification of Step S 430  is negative, e.g., “NO” at Step S 430 , then at Step S 432 , the CPU  11  may identify whether the connection checkless flag  13   b  is “1”. If the identification of Step S 432  is negative, e.g., “NO” at Step S 432 , then at Step S 434 , the CPU  11  may transmit a connection check command to the MFP  30 , i.e., the sender of the facsimile transmission data. Then, at Step S 436 , the CPU  11  may start the first timer  13   b , and may, at Step S 438 , identify whether an ACK command is received. That is, the BOX  10  observes the wireless communication with the MFP  30  via the transmission line  200 . 
         [0088]    If the identification of Step S 438  is negative, e.g., “NO” at Step S 438 , then at Step S 440 , the CPU  11  may identify whether the first timer  13   b  has reached a timeout. While the identification of Step S 438  is being negative, e.g., “NO” at Step S 440 , the CPU  11  may return to Step S 438 . Upon receiving an ACK command, e.g., “YES” at Step S 438 , while repeating the process in such a way, then at Step S 444 , the CPU  11  may start the second timer  13   c , and may, at Step S 446 , identify whether a transmission canceling command is received. 
         [0089]    If the identification of Step S 446  is affirmative, e.g., “YES” at Step S 446 , then the CPU  11  may end the facsimile transmission data transmission process and may cancel the transmission of the facsimile transmission data. Meanwhile, if the identification of Step S 446  is negative, e.g., “NO” at Step S 446 , then at Step S 448 , the CPU  11  then may identify whether the CPU  11  has finished the transmission of the facsimile transmission data. If the identification of Step S 448  is affirmative, e.g., “YES” at Step S 448 , then the CPU  11  ends the process. 
         [0090]    Meanwhile, if the identification of Step S 448  is negative, e.g., “NO” at Step S 448 , then at Step S 450 , the CPU  11  may identify whether the second timer  13   c  has reached a timeout. While the identification of Step S 450  is being negative, e.g., “NO” at Step S 450 , the CPU  11  may return to Step S 446 . If the identification of S 450  turns affirmative, e.g. “YES” at Step S 450  while the process is being repeated, then the CPU  11  returns to Step S 430 . 
         [0091]    If, e.g., the MFP  30  outputs a power-off command and the connection checkless flag  13   a  is set to “1” while the process is being repeated in such a way, the identification of Step S 432  turns affirmative, e.g., “YES” at Step S 432 , and the CPU  11  may skip Steps S 434 -S 444  and may stop the observation of the wireless communication via the transmission line  200 . If, e.g., the MFP  30  outputs a power-on command and the connection checkless flag  13   a  is set to “0” while the process is being repeated, the identification of Step S 432  turns negative, e.g. “NO” at Step S 432 , and the CPU  11  may restart the observation of the wireless communication that was stopped. 
         [0092]    Upon identifying a timeout of the first timer  13   b , e.g. “YES” at Step S 440  while the process is being repeated, the CPU  11  may detect the wireless communication with the MFP  30  via the transmission line  200  being disabled on the basis that the CPU  11  does not receive an ACK command in a given period of time. If that is the case, then at Step S 442 , CPU  11  may display on the LCD  18  a transmission canceling message such as “Facsimile transmission is canceled as communication with MFP is disabled”. Then, the CPU  11  may end the facsimile transmission data transmission process. The transmission of the facsimile transmission data thereby may be canceled. 
         [0093]    In the embodiment described above, the communication device, e.g., BOX  10  and the data processing device, e.g., MFP  30 , may be connected by wireless. Nevertheless, in another embodiment of the invention, the communication device and the data processing device may have a wired connection, and the communication between those devices may be disabled by, e.g., the snapping of the wire. 
         [0094]    In another embodiment of the invention, transmission line  200  may be a different transmission line than as described above. For example, in an embodiment of the invention, the transmission data may be an email, and the communication device may be a mail server, and the embodiment functions substantially as described above. 
         [0095]    In another embodiment of the invention, the communication device may be configured to retry transmitting a command to the data processing device if the data processing device does not reply to a previously transmitted command, and may detect that the communication with the MFP  30  via the transmission line  200  is disabled if the data processing device does not reply several times consecutively. 
         [0096]    Further, the above-described embodiments describe one MFP  30  connected to the BOX  10 . Nevertheless, in another embodiment of the invention, a plurality of MFPs  30  may be connected to the BOX  10 . In this embodiment, the BOX  10  may determine whether the wireless communication via the transmission line  200  should be observed, for each of the MFPs  30 . Specifically, if a power-off commend is transmitted from one of the MFPs  30  which is a sender of certain transmission data, BOX  10  may stop the observation of the communication with that MFP  30 , and may continue the observation of the communication with another one of the MFPs  30 , which is the sender of other transmission data. 
         [0097]    Similarly, if a power-on command is transmitted from one of the MFPs  30  which is the sender of certain transmission data, BOX  10  may again start the observation of the communication with that MFP  30 , and the observation of the communication with another one of the MFPs  30  for which the BOX  10  has stopped observation of the communication does not again start. 
         [0098]    While the invention has been described connection with various exemplary structures and illustrative embodiments, it will be understood by those skilled in the art that other variations and modifications of the structures and embodiments describes above may be made without departing from the scope of the invention. Other structures and embodiments will be apparent to those skilled in the art from a construction of the specification or practice of the invention disclosed herein. It is intended that the specification and described examples are illustrative with the true scope of the invention being defined by the following claims.