JP6343991B2 - Communication system, communication control method, and communication control program - Google Patents

Description

  The present invention relates to a communication system, a communication control method, and a communication control program. In particular, the present invention relates to a communication system, a communication control method, and a communication control program using a serial interface communication method.

  Serial communication is widely used in general computer systems. As one of serial communications, there is a method of registering an ID set in a slave device in a master device (ID: Identifier).

  Japanese Patent Application Laid-Open No. 2004-151820 discloses a method of executing polling using a table in which terminals are registered in a control method in a communication control apparatus that accepts transmission requests from terminals constituting a system by a polling method.

  In the polling method of Patent Document 1, the terminals constituting the system are registered in the system configuration terminal table. Then, when polling each terminal registered in the system configuration terminal table, only terminals that have responded with a device preparation completion are registered in the preparation completion terminal table. Furthermore, normal polling is performed based on the ready terminal table, and an active terminal table in which only terminals that have generated a transmission request within a certain period of time are created, and normal polling is performed based on the active terminal table. . According to the polling method of Patent Document 1, the polling frequency can be set to a balanced value by using various tables properly.

  Patent Document 2 discloses a communication system in which a plurality of modules set with unique addresses are connected to a communication bus, and the modules are designated using the set unique addresses to perform communication.

  In the communication system of Patent Literature 2, each slave module outputs a pre-response when receiving an address and a command from the master module, and outputs a response according to the reception status of the pre-response within a predetermined time, or performs communication. Select whether to cancel. If a pre-response is received within a predetermined time after outputting the pre-response, the address is duplicated with other slave modules. If the pre-response output by itself cannot be detected correctly, a collision has occurred. Therefore, according to the communication system disclosed in Patent Document 2, even when the same address is set to be duplicated in different slave modules, the responding slave modules are constant and the process is continued even if a collision occurs. can do.

JP-A-3-135243

  According to the polling method of Patent Document 1, the waste of polling can be reduced by managing the terminals constituting the system with a table. By the way, when the table management of Patent Document 1 is applied to a method of registering IDs set in a plurality of slave devices in the master device, if there is a mistake in ID setting / registration, which slave device ID is set by the master device. It is necessary to verify whether there was a setting / registration error. However, when a system is configured with a large number of slave devices, there is a problem that it is practically impossible to search the IDs of all slave devices. In addition, the slave device side has a problem that time-out monitoring is difficult to set unless the number of connections and communication time of other slave devices are restricted.

  Further, according to the communication system of Patent Document 2, it is not necessary to assign a unique identification number to each slave module, so that the load for diagnostic communication by the master module can be reduced. However, in the communication system of Patent Document 2, when a pre-response is detected or a collision occurs, the slave module stops communication. For this reason, there is a problem in that it becomes impossible to verify the slave module whose communication has been stopped from the master module side.

  The objective of this invention is providing the communication system which solves the subject mentioned above.

  The communication system of the present invention includes a master device and a plurality of slave devices connected to the master device by a serial interface, and the master device has a registration table in which identification numbers corresponding to the plurality of slave devices are registered. In response to a data transmission request received from one of the plurality of slave devices, the identification number registered in the registration table is sequentially transmitted to the plurality of slave devices, and the slave that has transmitted the data transmission request among the plurality of slave devices. The device determines whether or not its own device is registered in the registration table based on the identification number received from the master device.

  The communication control method of the present invention is a communication control method in a communication system in which a master device and a plurality of slave devices are connected by a serial interface, and in response to a data transmission request received from any of the plurality of slave devices, The identification number corresponding to each of the plurality of slave devices registered in the registration table of the master device is sequentially transmitted to the plurality of slave devices, and in the slave device that has transmitted the data transmission request among the plurality of slave devices, from the master device A communication control method for determining whether or not the own apparatus is registered in a registration table based on a received identification number.

  The communication control program of the present invention is a communication control program in a communication system in which a master device and a plurality of slave devices are connected by a serial interface, and in response to a data transmission request received from any of a plurality of slave devices, In the process of sequentially transmitting identification numbers corresponding to each of the plurality of slave devices registered in the registration table of the master device to the plurality of slave devices, and the slave device that has transmitted the data transmission request among the plurality of slave devices, Based on the identification number received from the apparatus, the computer is caused to execute processing for determining whether or not the own apparatus is registered in the registration table.

  According to the present invention, it is possible to quickly detect from the slave device side that the registration information of the registration table in which the identification number of the slave device is registered and the association between the actual identification number and the slave device are different. It is possible to provide a communication system that can be used.

It is a conceptual diagram which shows the structure of the communication system which concerns on the 1st Embodiment of this invention. It is an example of the ID table used with the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the master apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the slave apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart regarding operation | movement of the master apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart regarding operation | movement of the slave apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a sequence diagram regarding operation | movement of the communication system which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the structure of the communication system which concerns on the 1st Embodiment of this invention. It is an example of the ID table used with the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the master apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the slave apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart regarding operation | movement of the master apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart regarding operation | movement of the slave apparatus of the communication system which concerns on the 1st Embodiment of this invention. It is a sequence diagram regarding operation | movement of the communication system which concerns on the 1st Embodiment of this invention.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following.

(Embodiment)
(Constitution)
First, the communication system 1 according to the first embodiment of the present invention will be described.

  FIG. 1 is a block diagram showing a configuration of a communication system 1 according to the first embodiment of the present invention. The communication system 1 according to the present embodiment includes a master device 10, a plurality of slave devices 20-1 to N, and a serial interface 30 (N is a natural number). In FIG. 1, the ID value of each slave device 20 is a 2-byte numerical value. However, the ID value of each slave device 20 is not limited to 2 bytes and can be set to an arbitrary number of bytes.

  In the communication system 1 according to the present embodiment, an ID setting error of the slave device 20 and an ID registration information error of the master device 10 are detected by the configuration and operation described below.

  The master device 10 is a device that controls the serial interface. A plurality of slave devices 20 (slave devices 1, 2,..., N,...) Are connected to the serial interface 30. The ID of the slave device 1 is set to 0x0001, the ID of the slave device 2 is set to 0x0002,..., And the ID of the slave device N is set to 0xN. Then, the master device 10 stores an ID table 101 (FIG. 2) that is a correspondence table (also referred to as a registration table) between the device name and ID number of each slave device 20.

  In response to the data transmission request from the slave device 20, the master device 10 searches for the slave device 20 that has transmitted the data transmission request while referring to the ID table 101. The device search order of the slave devices 20 by the master device 10 is based on the order described in the registration table in which the IDs of the slave devices 20 are registered. The device search order of the master device 10 for the data transmission request of the slave device 20 may be determined in advance. A data transmission request by the slave device is called a break (BREAK), and a device search by the master device is called a sense (SENSE).

  The ID table 101 in FIG. 2 is an example of a registration table that registers the ID of the slave device 20. In the ID table 101 of FIG. 2, it is assumed that the ID of the slave device 20-n (hereinafter referred to as slave device N) should be registered as 0xN, but is erroneously registered as 0xN '. That is, in the ID table 101 of FIG. 2, the ID of the slave device N registered in the ID table 101 is not correct because there is an ID setting error of the slave device 20 or an ID registration information error of the master device 10. .

  In the ID table 101, the device name of the slave device 20 and the corresponding ID are registered. In the communication system 1 according to the present embodiment, the search method of the ID table 101 is determined in one direction. That is, each slave device 20 is searched in the order of slave device 1, slave device 2,..., Slave device N,. When the slave device 20 that has issued the data transmission request has not been searched yet at the stage where the search according to the ID table 101 is completed, the master device 10 executes the search from the slave 1 again. Note that the search order of the slave devices 20 is not limited to the order from the top of the ID table 101, and can be set in any order.

  The slave device 20 receives and reads the device search ID transmitted from the master device 10. Each slave device 20 sets / registers the ID as if its own ID was not searched (SENSE) when the same ID appeared twice, that is, when the search based on the ID table 101 by the master device 10 was completed. Perform error handling for mistakes.

  The error process is a process for notifying the host system that there is an error in the registration information of its own device in the ID table 101. For example, the error processing execution unit 23 indicates that an error has occurred via a different interface from the serial interface 30 to the devices and servers that are managing the status of the devices constituting the communication system 1 and collecting logs. It can be set as the structure to notify. Further, for example, the error processing execution means 23 may be configured to light a lamp provided in its own device or the master device 10 when an error occurs. However, the error processing in the communication system 1 according to the present embodiment is not limited to the example given here, and various error processing can be applied.

  Next, the internal configuration of the master device 10 and the slave device 20 will be described with reference to FIGS. 3 and 4.

[Master device]
The master device 10 shown in FIG. 3 includes a communication unit 11, a detection unit 12, a storage unit 13, and a search unit 14.

  The communication unit 11 transmits to each sleeve 20 a BRAK permission notification that permits a data transmission request (hereinafter, “BRAK”) from the slave device 20. In addition, the communication unit 11 receives the BREAK from each slave device 20 in response to the BREAK permission notification. In addition, the communication unit 11 transmits an apparatus search ID to each slave apparatus 20. The communication unit 11 performs data communication with the corresponding slave device 20 regarding the response to the device search ID.

  The detection unit 12 detects the break acquired through the communication unit 11 and issues an instruction to search the device to the search unit 14.

  The storage unit 13 stores the ID table 101.

  The search means 14 selects one ID to be transmitted to each slave device 20 from the ID table 101 in accordance with the break detected by the detection means 12, and outputs the selected ID to the communication means. The ID search order described in the ID table 101 can be arbitrarily set.

[Slave device]
The slave device 20 shown in FIG. 4 includes a transmission / reception unit 21, an identification number detection unit 22, an error processing execution unit 23, and a storage unit 24.

  The transmission / reception means 21 transmits a data transmission request as necessary when receiving a break permission from the master device 10. And the transmission / reception means 21 responds with respect to the master apparatus 10, and performs data communication, when ID transmitted from the master apparatus 10 is its own.

  The identification number detection means 22 receives the ID transmitted from the master device 10 and determines whether or not the received ID is its own. When the identification number detection unit 22 receives its own ID after the data transmission request, the identification number detection unit 22 issues an instruction to respond to the master device to the transmission / reception unit 21. When the identification number detection unit 22 receives another ID after the data transmission request, the identification number detection unit 22 instructs the transmission / reception unit 21 to issue the data transmission request again. The identification number detection means 22 notifies the error processing execution means 23 that there is an error when the ID is not received but another ID is received twice.

  The error processing execution unit 23 executes error processing in response to the notification from the identification number detection unit 22.

  The storage unit 24 stores data exchanged with the master device 10 and stores an ID received first after a data transmission request.

  The above is description regarding the structure of the communication system 1 which concerns on the 1st Embodiment of this invention. Each component described above is realized by hardware / software constituting an information processing apparatus such as a computer or a server.

(Operation)
Next, the operation of the communication system 1 according to the first embodiment of the present invention will be described. The operation of the master device 10 will be described with reference to FIG. 5, the operation of the slave device 20 will be described with reference to FIG. 6, and the operation relationship between the master device 10 and the slave device 20 will be described with reference to FIG.

[Master device]
The operation of the master device 10 will be described using the flowchart of FIG. It is assumed that the order of device search (SENSE) by the master device 10 in response to the data transmission request (BREAK) from the slave device 20 is the registration order (order from the top) of the ID table 101.

  First, in FIG. 5, the master device 10 detects the break transmitted from any of the slave devices 20 (step S <b> 10).

  Next, the master device 10 selects one of the device IDs registered in the ID table 101 (step S11).

  Specifically, the master device 10 that has detected the data transmission request (BREAK) first selects one ID for device search (SENSE) from the ID table 101. Then, a device search (SENSE) is performed on the selected ID.

  If the slave device 20 that has been searched (SENSE) by the master device 10 is not the data transmission request source, the data transmission request (BREAK) is again transmitted to the master device 10 from the slave device 20 that issued the data transmission request. It will be. In that case, the master device 10 that has detected the data transmission request (BREAK) advances the ID table 101 and determines an ID for performing device search (SENSE).

  Next, the master device 10 performs a device search (SENSE) with the selected ID. That is, the master device 10 transmits a SENSE command including the selected ID to each slave device 20 (step S12).

  Here, when the master device 10 receives a response to the data transmission request from any of the slave devices 20 (Yes in step S13), the master device 10 performs data communication processing with the responding slave device 20 (step S14).

  On the other hand, if there is no data transmission request (No in step S13), the master device 10 once ends the process. Each time the master device 10 receives a data transmission request, the master device 10 repeats the processes of steps S10 to S14.

  The above is the description of the operation of the master device 10.

[Slave device]
Subsequently, the operation of the slave devices 1, 2,..., N will be described using the flowchart of FIG.

  First, it is assumed that there is a need for a data transmission request in the slave device 20-n (hereinafter, slave device N) (step S20).

  Next, when the slave device N in which the necessity of the data transmission request is generated detects permission of the data transmission request (BREAK) (Yes in step S21), the slave device N transmits the data transmission request (BREAK) (step S22). Note that the slave device N in which the necessity of the data transmission request has occurred becomes a standby state (No in step S21) when the data transmission request permission is not detected (return to step S20).

  Next, the slave device N receives the ID (SENSE_ID) transmitted by the device search (SENSE) of the master device 10 (step S23).

  Here, when SENSE_ID is its own ID (Yes in Step S24), the slave device N executes data communication processing with the master device 10 (Step S25).

  On the other hand, when SENSE_ID is not its own ID (No in step S24), the slave device N performs different processing depending on whether or not the data transmission request transmitted by itself is the first time (step S26).

  Here, when the data transmission request by the slave device N is the first time (Yes in step S26), the slave device N stores the ID (hereinafter, first_ID) of the device search (SENSE) immediately after the data transmission request (BREAK). (Step S27).

  On the other hand, if the data transmission request by the slave device N is not the first time (No in step S26), if SENSE_ID matches the first_ID (Yes in step S28), the slave device N executes error processing (step S29). ). That is, when the device search (SENSE) of first_ID is executed again without specifying its own ID, error processing is executed assuming that the ID of the slave device N is not correctly registered in the ID table 101 of the master device 10. To do.

  Further, if the data transmission request by the slave device N is not the first time (No in step S26), and SENSE_ID does not match the first_ID (Yes in step S28), the slave device N waits for the data transmission request again (step S28). (Return to step S20).

  The above is the description of the operation of the slave devices 1, 2,..., N.

[Sequence Diagram]
Finally, the operational relationship between the master device 10 and each slave device 20 will be described using the sequence diagram of FIG.

  First, the T11 section in FIG. 7 will be described. When the break permission is transmitted from the master device 10 to each slave device 20, each slave device 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 10. The master device 10 transmits SENSE_ID (0x0001) in response to the data transmission request. The slave 1 performs data communication with the master device 10 in response to the SENSE_ID transmitted from the master device 10.

  In T11, although a data transmission request was issued from the slave device N, the master device 10 transmitted SENSE_ID corresponding to the slave device 1. Therefore, the slave device 1 responds to the master device 10. At this time, the slave device N stores the received SENSE_ID (0x0001) of the slave device 1 as first_ID.

  Next, the section T12 in FIG. 7 will be described. When the break permission is transmitted from the master device 10 to each slave device 20, each slave device 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 10 again. The master device 10 transmits SENSE_ID (0x0002) in response to the data transmission request. The slave device 2 performs data communication with the master device 10 in response to the SENSE_ID transmitted from the master device 10.

  In the T12 section, although the data transmission request is issued again from the slave device N, the SENSE_ID corresponding to the slave device 2 is transmitted from the master device 10. Therefore, the slave device 2 responds to the master device 10.

  Next, the T13 section in FIG. 7 will be described. When the break permission is transmitted from the master device 10 to each slave device 20, each of the slave devices 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 10 again. The master device 10 transmits SENSE_ID (0xN ′) in response to the data transmission request. However, no device responds to the SENSE_ID transmitted from the master device 10 in the T13 period. Therefore, none of the slave devices 20 responds to the master device 10.

  Next, the T14 section will be described. When the break permission is transmitted from the master device 10 to each slave device 20, each slave device 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 10 again. The master device 10 transmits SENSE_ID (0x0001) in response to the data transmission request. At this time, the master device 10 transmits the ID of the slave device 1 again because the devices registered in the ID table 101 have made a round. Here, the slave N receives SENSE_ID that matches the stored first_ID. That is, the slave device N recognizes that its own ID registered in the ID table 101 is incorrect. Therefore, the slave device N performs error processing.

  The above is the description of the operation of the communication system 1 according to the first embodiment of the present invention.

(effect)
As described above, according to the communication system according to the present embodiment, an ID setting / registration error can be quickly detected on the slave device side by reading the device search algorithm of the master device and reading the search ID of the slave device.

  Data communication in a form in which a plurality of slave devices are connected to a master device that takes the initiative in controlling one interface targeted by the communication system according to the embodiment of the present invention is used particularly in serial communication.

In a general system, when there is an ID number setting error of the slave device or a setting error of the slave ID registration information of the master device, the following situation occurs.
1) The slave device raises a data transmission request (BREAK) to the master device.
2) The master device searches for devices one by one from the ID registration information (SENSE), but the master device cannot find the requesting slave device due to an ID setting / registration error.
3) The slave device cannot monitor the timeout because there is a possibility that data transfer of other slave devices may occur. In addition, since the slave device does not know how many other slave devices are connected, it continues to raise the data transmission request (BREAK).

  As described above, in a general method, setting errors cannot be easily detected in both the master device and the slave device, and an extra load is imposed on the communication processing and interface of the master device.

  On the other hand, according to the communication system according to the present embodiment, in data communication in which the ID number of the slave device is previously set in the ID registration information of the master device, an ID setting error of the slave device or an ID registration information setting error of the master device is detected. It becomes possible to detect promptly.

(Second Embodiment)
Next, a communication system according to the second embodiment of the present invention will be described.

  FIG. 8 is a block diagram showing the configuration of the communication system 2 according to the second embodiment of the present invention. The communication system 2 according to the present embodiment includes a master device 40, a plurality of slave devices 50-1 to N, and a serial interface 60 (N is a natural number). The master device 40, the plurality of slave devices 50-1 to N and the serial interface 60 in FIG. 8 are the same as the master device 10, the plurality of slave devices 20-1 to 20-N and the serial interface 60 in FIG. It has the same functional configuration as the interface 30.

  In the communication system 2 according to the present embodiment, the master device 40 stores an ID table 102 (FIG. 9) that is a correspondence table (also referred to as a registration table) between the device name and ID number of each slave device 50. The ID table 102 in FIG. 9 has a transmitted flag column added to the ID table 101 in FIG. Similar to the ID table 101 in FIG. 2, the ID of the slave device N in the ID table 102 in FIG. 9 should be registered as Nx0, but is erroneously registered as N′x0.

[Master device]
As shown in FIG. 10, the master device 40 includes a communication unit 41, a detection unit 42, a storage unit 43, a search unit 44, a flag setting unit 45, and a reservation identification number setting unit 46. That is, the master device 40 according to the second embodiment has a configuration in which a flag setting unit 45 and a reservation identification number setting unit 46 are added to the master device 10 according to the first embodiment. The communication means 41, detection means 42, storage means 43, and search means 44 in FIG. 10 have the same functional configuration as the communication means 11, detection means 12, storage means 13, and search means 14 in FIG. Detailed description will be omitted.

  In the ID table 102, the flag setting unit 45 sets a transmitted flag for the ID for which the device search (SENSE) has been performed.

  The reservation identification number setting means 46 uses a reservation ID (also referred to as a reservation identification number) when it is confirmed by the transmitted flag that the device search (SENSE) for the set slave device 50 has been completed without data communication processing. Issue a device search (SENSE).

[Slave device]
As shown in FIG. 11, the slave device 50 includes a transmission / reception unit 51, a reservation identification number detection unit 52, an error process execution unit 53, and a storage unit 54. That is, the slave device 50 according to the second embodiment has a configuration in which the identification number detection unit 22 of the slave device 20 according to the first embodiment is replaced with a reservation identification number detection unit 52. The transmission / reception means 51 and error processing execution means 53 in FIG. 11 have the same functional configuration as the transmission / reception means 21 and error processing execution means 23 in FIG.

  When the reservation ID is detected twice in the device search (SENSE), the reservation identification number detection unit 52 determines that the ID of the own device is not correctly registered in the master device 0 and performs error processing in the error processing execution unit. Instruct.

  The storage unit 54 stores data exchanged with the master device 40 and stores the reservation ID detected by the reservation identification number detection unit 52.

  The above is description regarding the structure of the communication system 2 which concerns on the 2nd Embodiment of this invention. Each component described above is realized by hardware / software constituting an information processing apparatus such as a computer or a server.

(Operation)
Next, the operation of the communication system 2 according to the second embodiment of the present invention will be described. The operation of the master device 40 will be described with reference to FIG. 12, the operation of the slave device 50 will be described with reference to FIG. 13, and the operation relationship between the master device 40 and the slave device 50 will be described with reference to FIG.

[Master device]
The operation of the master device 40 will be described using the flowchart of FIG. Note that the order of the device search (SENSE) by the master device 40 in response to the data transmission request (BREAK) from the slave device 50 is not limited to the registration order of the ID table 102, and is executed in an arbitrary order.

  First, in FIG. 12, the master device 40 detects BRAKE transmitted from any slave device 50 (step S40).

  Next, the master device 40 refers to the transmission flag in the ID table 102, and determines whether or not the SENSE_ID has already been transmitted (step S41).

  If there is an ID for which the transmission flag is not set (No in step S41), the master device 40 selects one of the device IDs registered in the ID table 102 (step S42).

  Specifically, the master device 40 that has detected the data transmission request (BREAK) selects from the ID table 102 one ID for which the transmission flag is not set as a device search (SENSE) target. Then, a device search (SENSE) is performed on the selected ID.

  If the slave device 50 that has been searched (SENSE) by the master device 40 is not a data transmission request source, a data transmission request (BREAK) is transmitted again to the master device 40 from the slave device 50 that issued the data transmission request. It will be. In this case, the master device 40 that has detected the data transmission request (BREAK) determines one other ID for which no transmission flag is set from the ID table 102 as a device search (SENSE) target.

  Next, the master device 40 performs a device search (SENSE) with the selected ID. That is, the master device 40 transmits a SENSE command including the selected ID to each slave device 50 (step S43).

  Here, when receiving a response to the data transmission request from any of the slave devices 50 (Yes in step S44), the master device 40 clears all the transmitted flags that have been assigned to the device that has already transmitted the ID. (Step S45).

  Then, the master device 40 performs data communication processing with the responding slave device 50 (step S46).

  On the other hand, if there is no data transmission request (No in step S44), the master device 40 sets the transmission flag of the transmission destination device of this SENSE_ID (step S47), and once ends the process.

  By the way, if there is no ID for which the transmission flag is not set in step S41 (Yes in step S41), the master device 40 executes device search (SENSE) with the reservation ID registered in the ID table 102 (step S48). ). The transmission of the reservation ID means that a device search (SENSE) has been performed for all IDs registered in the ID table 102.

  When executing the device search (SENSE) based on the reservation ID, the master device 40 clears all the transmitted flags that have been assigned to the device that has already transmitted the ID (step S49), and once ends the processing.

  Each time the master device 40 receives a data transmission request, the master device 40 repeats the processes of steps S40 to S49.

  The above is the description of the operation of the master device 40.

[Slave device]
Next, the operation of the slave devices 1, 2,..., N will be described using the flowchart of FIG. The operation of the slave device 50 according to the second embodiment shown in FIG. 13 is the same flow as that of the slave device 20 according to the first embodiment shown in FIG.

  First, it is assumed that there is a need for a data transmission request in the slave device 50-n (hereinafter, slave device N) (step S50).

  Next, when the slave device N that has generated the necessity for the data transmission request detects permission of the data transmission request (BREAK) (Yes in step S51), the slave device N transmits the data transmission request (BREAK) (step S52). Note that the slave device N in which the necessity of the data transmission request has occurred becomes a standby state (No in step S51) when the data transmission request permission is not detected (return to step S50).

  Next, the slave device N receives the ID (SENSE_ID) transmitted by the device search (SENSE) of the master device 40 (step S53).

  Here, when SENSE_ID is its own ID (Yes in Step S54), the slave device N executes data communication processing with the master device 40 (Step S55).

  On the other hand, when SENSE_ID is not its own ID (No in step S54), the slave device N performs different operations depending on whether or not SENSE_ID is a reservation ID (step S56).

  Here, when the SENSE_ID received by the slave device N is not the reservation ID (No in step S56), the slave device N waits for the timing of the data transmission request again (returns to step S50).

  Here, the slave device N performs different operations depending on the number of reservation IDs received by the slave device N (step S57).

  If the reservation ID has been received for the second time (Yes in step S57), the slave device N executes error processing (step S59). That is, when the device search (SENSE) of the reservation ID is executed again without specifying its own ID, the error processing is performed assuming that the ID of the slave device N is not correctly registered in the ID table 101 of the master device 40. Run.

  If the reservation ID is received for the first time (No in step S57), the slave device N again waits for the timing of the data transmission request (returns to step S50).

  The above is the description of the operations of the slave devices 1, 2,.

[Sequence Diagram]
Finally, the operational relationship between the master device 40 and each slave device 50 will be described using the sequence diagram of FIG.

  First, the T21 section in FIG. 14 will be described. When the break permission is transmitted from the master device 40 to each slave device 50, each of the slave devices 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 40. The master device 40 transmits SENSE_ID (0x0001) in response to the data transmission request. The slave 1 performs data communication with the master device 40 in response to the SENSE_ID transmitted from the master device 40.

  In T21, a data transmission request was issued from the slave device N, but the SENSE_ID corresponding to the slave device 1 was transmitted from the master device 40. Therefore, the slave device 1 responds to the master device 40. At this time, the master device 40 sets a transmitted flag to ID0x0001 of the ID table 102. Unlike the first embodiment, the slave device N does not have to store the received SENSE_ID (0x0001) of the slave device 1 as the first_ID.

  In the sequence diagram according to the second embodiment in FIG. 14, the T12 section shown in the sequence diagram according to the first embodiment in FIG. 7 is omitted. 14 correspond to the T13 section and the T14 section in FIG. 7, respectively.

  Next, the T22 section in FIG. 14 will be described. When the break permission is transmitted from the master device 40 to each slave device 50, each of the slave devices 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 40 again. The master device 40 transmits SENSE_ID (0xN ′) in response to the data transmission request. However, no device responds to SENSE_ID transmitted from the master device 40 in the T22 section. Therefore, no slave device 50 responds to the master device 40. At this time, the master device 40 sets a transmitted flag to ID0xN ′ of the ID table 102.

  Next, the T23 section will be described. At the stage of the T23 interval, the master device 40 has completed the device search (SENSE) for the ID registered in the ID table 102 without any data communication processing. Therefore, the master device 40 issues a device search (SENSE) using the reservation ID (0xFFFF in FIG. 9). Here, when a break permission is transmitted from the master device to each slave device 50, each of the slave devices 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 40 again. The master device 40 transmits the reservation ID (0xFFFF) in response to the data transmission request. However, no device responds to the reservation ID transmitted from the master device 40 in the T23 section. Therefore, no slave device 50 responds to the master device 40.

  Next, the T24 section will be described. When the break permission is transmitted from the master device 40 to each slave device 50, each of the slave devices 1 to N receives the break permission. Here, the slave device N transmits a data transmission request to the master device 40 again. The master device 40 transmits the reservation ID (0xFFFF) in response to the data transmission request. At this time, the slave device N has received the reservation ID (0xFFFF) that has already been stored. Therefore, the slave device N recognizes that its own ID registered in the ID table 102 is incorrect. That is, from the slave device side, detecting the reservation ID for the second time after raising BRAK can confirm that the ID of the own device is not registered in the ID table 102 of the master device 40. In response to the result, the slave device N executes error processing.

  The above is the description of the operation of the communication system 2 according to the second embodiment of the present invention.

  As described above, in the communication system according to the present embodiment, the transmitted flag is provided in the ID table 102 of the master device 40, and the transmitted flag is set for the ID for which the device search (SENSE) has been performed. When the slave device 50 that has raised the data transmission request (BREAK) is found and the data communication process is performed, the master device 40 clears all the transmitted flags in the ID table 102.

  When the device search (SENSE) for the set slave device 50 is completed without data communication processing by the transmitted flag, the master device 40 uses the reservation ID (0xFFFF in FIG. 9) to search for the device (SENSE). ) Is issued (FIG. 12). Also at this time, the master device 40 clears all the transmitted flags in the ID table 102.

  On the other hand, the slave device N issues a data transmission request (BREAK) every time a data transmission request is generated. The difference from the first embodiment is that if the reservation ID is detected twice by device search (SENSE), it is determined that the ID of the own device is not correctly registered in the master device 40 and error processing is performed.

  In the first embodiment, the device search (SENSE) of the master device 10 is performed in the registration order of the ID table 101. On the other hand, in the second embodiment, the search order of the ID table 102 is not fixed because the transmitted flag and the reservation ID are used. For example, if it is expected that there is a high possibility that the slave device 50 that has performed data communication processing immediately before will continue to raise data communication requests, it is efficient to perform device search (SENSE) of the same device continuously. . In such a case, the second embodiment that is not limited to the device search (SENSE) order is effective.

  As described above, according to the communication system according to the embodiment of the present invention, the registration information of the registration table in which the identification number of the slave device is registered and the correspondence between the actual identification number and the slave device are different. Can be promptly detected from the slave device side.

  The communication control method described in the embodiment of the present invention is not limited to the configuration of the present embodiment, but may be applied to the above-described method / method or the analogy from the above-described method / method. It is included in the range. A program for causing a computer to execute the communication control method according to the embodiment of the present invention is also included in the scope of the present invention. Further, a program storage medium storing the program of the present invention is also included in the scope of the present invention.

  Further, an information processing apparatus such as a computer to which the communication system according to the embodiment of the present invention is applied is included in the scope of the present invention. A computer system in which the communication system according to the embodiment of the present invention is applied to the connection between the information processing apparatus and the external device is also included in the scope of the present invention. A server system in which the communication system according to the embodiment of the present invention is applied to connection between a host device and a plurality of guest devices is also included in the scope of the present invention.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Communication system 10 Master apparatus 11 Communication means 12 Detection means 13 Storage means 14 Search means 20 Slave apparatus 21 Transmission / reception means 22 Identification number detection means 23 Error processing execution means 24 Storage means 30 Serial interface 40 Master apparatus 41 Communication means 42 Detection means 43 Storage means 44 Search means 45 Flag setting means 46 Reservation identification number setting means 50 Slave device 51 Transmission / reception means 52 Reservation identification number detection means 53 Error processing execution means 54 Storage means 60 Serial interface

Claims (9)

A master device;
A plurality of slave devices connected by a serial interface with the master device,
The master device is
A registration table in which identification numbers corresponding to the plurality of slave devices are registered;
In response to a data transmission request received from any of the plurality of slave devices, the identification numbers registered in the registration table are sequentially transmitted to the plurality of slave devices,
Of the plurality of slave devices, the slave device that transmitted the data transmission request,
Based on the identification number received from the master device, it is determined whether or not the device is registered in the registration table, and the registration table is received when the same identification number is received twice after transmitting the data transmission request. A communication system that determines that the own device is not registered in the network. The master device is
Each time the data transmission request is received, the identification numbers are transmitted to the plurality of slave devices in the order set in the registration table,
Of the plurality of slave devices, the slave device that transmitted the data transmission request,
The identification number received first after transmitting the data transmission request is recorded, and when the recorded identification number is received twice, it is determined that the own device is not registered in the registration table. The communication system described. The master device is
Transmitting a data transmission request permission notification permitting a data transmission request from the slave device to the plurality of slave devices, receiving the data transmission request from the slave device in response to the data transmission request permission notification, and Communication means for transmitting the identification number for device search to a slave device of the device and performing data communication with the corresponding slave device regarding a response to the identification number;
Detecting means for detecting the data transmission request acquired via the communication means and issuing an instruction to search for a slave device that has transmitted the data transmission request;
Storage means for storing the registration table;
Search means for selecting one of the identification numbers to be transmitted to the plurality of slave devices from the registration table in response to the data transmission request detected by the detection means, and outputting the selected identification number to the communication means; Have
The slave device is
When the data transmission request permission notification is received from the master device, the data transmission request is transmitted as necessary. When the identification number received from the master device is that of the own device, the master device A transmission / reception means for executing data communication in response;
Receiving the identification number transmitted from the master device, determining whether the received identification number is that of the own device, and receiving the identification number of the own device after issuing the data transmission request In response, an instruction to respond to the master device is issued to the transmission / reception means, and an instruction to transmit the data transmission request is received when the identification number of another slave device is received after issuing the data transmission request. An identification number detecting means for sending to the transmitting / receiving means;
The communication system according to claim 2 , further comprising storage means for storing data exchanged with the master device and storing the identification number received first after transmission of the data transmission request. An error processing execution means for executing error processing is provided,
The identification number detecting means includes
When the identification number of the other device is received twice even though the identification number of the own device is not received, an instruction to execute the error processing is issued to the error processing execution means,
The error processing execution means includes
The communication system according to claim 3, wherein the error processing is executed in response to an instruction from the identification number detection unit. The master device is
In the registration table, set a transmitted flag to the transmitted identification number,
When the transmitted flag is set for all of the identification numbers registered in the registration table, a reservation identification number indicating that the transmitted flag is set for all of the identification numbers registered in the registration table To the plurality of slave devices,
Of the plurality of slave devices, the slave device that transmitted the data transmission request,
The communication system according to claim 1, wherein the reservation identification number transmitted from the master device is stored, and it is determined that the own device is not registered in the registration table when the reservation identification number is received again. The master device is
A data transmission request permission notification for permitting a data transmission request from the slave device is transmitted to the plurality of slave devices, and the data transmission request is received from the slave device in response to the data transmission request permission notification. Communication means for transmitting the identification number for device search to a slave device of the device and performing data communication with the corresponding slave device regarding a response to the identification number;
Detecting means for detecting the data transmission request acquired via the communication means and issuing an instruction to search for a device that has transmitted the data transmission request;
Storage means for storing the registration table;
Search means for selecting one of the identification numbers to be transmitted to the plurality of slave devices from the registration table in response to the data transmission request detected by the detection means, and outputting the selected identification number to the communication means; ,
Flag setting means for setting the transmitted flag to the identification number in the registration table;
Reservation identification number setting means for transmitting the reservation identification number to the plurality of slave devices,
The slave device is
When the data transmission request permission notification is received from the master device, a data transmission request is transmitted as necessary. When the identification number received from the master device is that of the own device, the master device responds to the master device. Transmitting and receiving means for performing data communication,
Reservation identification number detection means for determining that the device is not registered in the registration table when the reservation identification number is received twice, and instructing error processing;
Error processing execution means for executing the error processing in response to an instruction from the reservation identification number detection means;
The communication system according to claim 5, further comprising storage means for storing data exchanged with the master device and storing the reservation identification number transmitted from the master device. A communication control method in a communication system in which a master device and a plurality of slave devices are connected by a serial interface,
In response to a data transmission request received from any of the plurality of slave devices, identification numbers corresponding to each of the plurality of slave devices registered in the registration table of the master device are sequentially transmitted to the plurality of slave devices. And
In the slave device that has transmitted the data transmission request among the plurality of slave devices, it is determined whether the device is registered in the registration table based on the identification number received from the master device, and the data transmission A communication control method for determining that the own device is not registered in the registration table when the same identification number is received twice after transmitting a request.   The communication control according to claim 7, wherein after the data transmission request is transmitted by the slave device, it is determined that the own device is not registered in the registration table when the same identification number is received twice by the slave device. Method. A communication control program in a communication system in which a master device and a plurality of slave devices are connected by a serial interface,
In response to a data transmission request received from any of the plurality of slave devices, identification numbers corresponding to each of the plurality of slave devices registered in the registration table of the master device are sequentially transmitted to the plurality of slave devices. Processing to
In the slave device that has transmitted the data transmission request among the plurality of slave devices, it is determined whether the device is registered in the registration table based on the identification number received from the master device, and the data transmission A communication control program for causing a computer to execute a process of determining that its own device is not registered in the registration table when the same identification number is received twice after transmitting a request.

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