Computer program for terminal device, and terminal device

Abstract

To provide a technique that allows a terminal device to communicate with a communication device using an appropriate protocol.SOLUTION: When a first setting instruction is obtained for transmitting a setting command to a first communication device that supports a first protocol and does not support a second protocol, a terminal device transmits a first setting command that is according to the first protocol to the first communication device. When a second setting instruction is obtained for transmitting a setting command to a second communication device that supports the first protocol and the second protocol, the terminal device transmits a second setting command that is according to the second protocol to the second communication device.SELECTED DRAWING: Figure 3

Description

Technical Field

[0005]

[0001] This specification discloses a technology related to a terminal device that executes communication with a communication device that stores management information in which an OID (abbreviation for Object ID) is associated with a set value.

Background Art

[0002] Patent Document 1 discloses a management device that manages devices according to SNMP (abbreviation for Simple Network Management Protocol).

Prior Art Documents

Patent Documents

[0006] According to the above configuration, the terminal device sends a first configuration command in accordance with the first protocol to a first communication device that supports the first protocol but not the second protocol, and sends a second configuration command in accordance with the second protocol to a second communication device that supports both the first and second protocols. Therefore, the terminal device can send configuration commands to the communication device using the appropriate protocol.

[0007] This specification also discloses a computer program for a terminal device. The computer program controls the computer of the terminal device to the following parts: a first acquisition command transmission unit which transmits a first acquisition command in accordance with the first protocol to the first communication device when a first acquisition instruction is obtained for transmitting an acquisition command to a first communication device which supports the first protocol but does not support the second protocol, wherein the first acquisition command includes a third OID (abbreviation for Object ID) of the MIB (abbreviation for Management Information Base), and the first acquisition command is a command that requests the transmission of a third setting value associated with the third OID in the first management information of the first communication device; a first response command receiving unit which receives a first response command including the third setting value from the first communication device when the first acquisition command is transmitted to the first communication device; and a second acquisition instruction which transmits a first acquisition command in accordance with the second protocol to the second communication device when a second acquisition instruction is obtained for transmitting an acquisition command to a second communication device which supports the first protocol and the second protocol. A second acquisition command transmitting unit that transmits a second acquisition command in accordance with a code to the second communication device, wherein the second acquisition command includes a fourth OID of the MIB, and the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information of the second communication device; and a second response command receiving unit that receives a second response command from the second communication device, including the fourth setting value, when the second acquisition command is transmitted to the second communication device.

[0008] According to the above configuration, the terminal device sends a first acquisition command in accordance with the first protocol to a first communication device that supports the first protocol but not the second protocol, and sends a second acquisition command in accordance with the second protocol to a second communication device that supports both the first and second protocols. Therefore, the terminal device can send acquisition commands to the communication device using the appropriate protocol.

[0009] The computer-readable storage medium for storing the above-mentioned computer program, as well as the terminal device itself, are novel and useful. Furthermore, the method executed by the terminal device is also novel and useful. Additionally, a communication system comprising the above-mentioned terminal device, a first communication device, and a second communication device is also novel and useful. [Brief explanation of the drawing]

[0010] [Figure 1] A diagram showing the configuration of a communication system. [Figure 2] This figure shows an example of each table. [Figure 3] This diagram shows a flowchart of command processing. [Figure 4] This is a flowchart of SNMP processing. [Figure 5] This diagram shows a flowchart of HTTPS processing. [Figure 6] This diagram shows the sequences for Case A and Case B when HTTPS is used. [Figure 7] This figure shows the sequences for Case C and Case D when SNMP is used. [Figure 8] This diagram shows the sequence of cases where writing the setting value fails in the comparative example. [Modes for carrying out the invention]

[0011] (Configuration of communication system 2; Figure 1) As shown in Figure 1, the communication system 2 comprises printers 10A and 10B and a terminal device 100. Each device 10A, 10B, and 100 is connected to a LAN (Local Area Network) 6 and can communicate with each other via the LAN 6. The LAN 6 may be a wired LAN or a wireless LAN. In this embodiment, the printers 10A and 10B write or transmit setting values ​​in response to request commands from the terminal device 100 (i.e., SET commands, POST commands, or GET commands described later).

[0012] (Configuration of printers 10A and 10B) Each printer 10A and 10B is a peripheral device (for example, a peripheral device of terminal device 100) capable of performing printing functions. In a modified example, each printer 10A and 10B may be a multi-function device capable of performing scanning functions, fax functions, etc., in addition to printing functions.

[0013] Printer 10A supports SNMP (Simple Network Management Protocol) but does not support HTTPS (Hyper Text Transfer Protocol Secure). SNMP and HTTPS will be explained in more detail later.

[0014] The printer 10A is equipped with non-volatile memory 34A and volatile memory 36A. Non-volatile memory 34A is a memory in which stored information is not erased even when the power of the printer 10A is turned off. Non-volatile memory 34A stores the first management table 38A. Volatile memory 36A is a memory in which stored information is erased when the power of the printer 10A is turned off. Volatile memory 36A temporarily stores information necessary for the printer 10A to perform processing.

[0015] Printer 10B supports SNMP and also supports HTTPS. Printer 10B includes a non-volatile memory 34B in which a second management table 38B is stored, and a volatile memory 36B. Hereinafter, printers 10A and 10B may be collectively referred to as "printer 10".

[0016] (Configuration of Terminal Device 100) Terminal device 100 is a user terminal such as a desktop PC, a notebook PC, a tablet PC, a mobile phone (e.g., a smartphone). Terminal device 100 includes an operation unit 112, a display unit 114, a communication interface 116, and a control unit 130. Hereinafter, the interface may be referred to as "I / F".

[0017] Operation unit 112 is an I / F for inputting various instructions to terminal device 100. Display unit 114 is a display for displaying various information. Display unit 114 is a so-called touch panel and also functions as an operation unit. Communication I / F 116 is connected to LAN 6. Communication I / F 116 may be a wireless I / F or a wired I / F.

[0018] Control unit 130 includes a CPU 132 and a memory 134. CPU 132 executes various processes according to programs 136 and 138 stored in memory 13'. Memory 134 is composed of a volatile memory, a non-volatile memory, etc. Memory 134 stores an OS (abbreviation for Operating System) program 136 and a setting application 138. Hereinafter, setting application 138 may be referred to as "application 138". OS program 136 is a program for controlling the basic operations of terminal device 100. Application 138 is an application for managing printer 10 using terminal device 100. Although not shown in the figure, in memory 134, similar to the first management table 38A of printer 10A, the content of information and the OID are stored in association with each other.

[0019] (Description of the First Management Table 38A and the Second Management Table 38B; FIG. 2) Referring to FIG. 2, the First Management Table 38A stored in the non-volatile memory 34A of the printer 10A and the Second Management Table 38B stored in the non-volatile memory 34B of the printer 10B will be described.

[0020] The First Management Table 38A is a table for storing various information of the printer 10A. The information includes, for example, the administrator address of the printer 10A, the remaining amount of consumables, the MAC address, etc.

[0021] The information stored in the First Management Table 38A further includes communication settings for the printer 10A to execute communication. The communication settings include the IP address of the printer 10A, Proxy settings, etc. Information not illustrated in FIG. 2 includes APIPA (abbreviation for Automatic Private IP Addressing) settings, Network Reset, Reboot (i.e., restart), the installation location of the printer 10A, the access destination, the error history, the status (printing in progress, standby, etc.), printing settings (e.g., default print resolution), etc. The First Management Table 38A stores the above various information using a tree structure (i.e., a hierarchical structure). A set of various information having this tree structure is called "MIB" (abbreviation for Management Information Base).

[0022] Specifically, the First Management Table 38A stores by associating the content, the OID (abbreviation for Object ID), and the MIB value. The content is a character string indicating the meaning of the information. The OID is an identifier for identifying the information. The MIB value indicates the specific value (i.e., the set value) of the information.

[0023] The second management table 38B is a table for storing various information about the printer 10B. In this embodiment, the information stored in the second management table 38B is the same as the information stored in the first management table 38A. In modified examples, the information stored in the second management table 38B and the information stored in the first management table 38A may be different.

[0024] The second management table 38B stores the content, OID, MIB value, and security information in association with each other. The security information indicates either "High," which indicates information with a high security level, or "Low," which indicates information with a low security level.

[0025] (Communication protocol between each printer 10A, 10B and terminal device 100) For communicating MIB values ​​between the printer 10A and the terminal device 100, protocols following UDP (User Datagram Protocol) of the transport layer of the OSI (Open Systems Interconnection) reference model are widely known. Specifically, SNMP (Simple Network Management Protocol) is a well-known example. In this embodiment, the terminal device 100 uses a communication protocol following TCP (Transmission Control Protocol) of the transport layer of the OSI reference model, in addition to SNMP, as a communication protocol for communicating MIB values. Specifically, HTTPS (Hyper Text Transfer Protocol Secure) is used. HTTPS employs user authentication and data encryption, thus offering a higher level of security than SNMP.

[0026] In Figure 2, the security information "High" in the second management table 38B indicates that writing or sending MIB values ​​is prohibited when an SNMP-compliant request command is received from an external device. Conversely, the security information "Low" indicates that writing or sending MIB values ​​is permitted when an SNMP-compliant request command is received from an external device. Printer 10B allows writing or sending MIB values ​​when an HTTPS-compliant request command is received, regardless of whether the security information is "High" or "Low".

[0027] (Command processing of terminal device 100: Figure 3) Referring to Figure 3, the command processing executed by the CPU 132 of the terminal device 100 according to the application 138 will be explained. When the application 138 is launched, the processing shown in Figure 3 is executed. Note that all communications in this embodiment are performed via the communication interface 116, so the phrase "via the communication interface 116" will be omitted below.

[0028] In S10, the CPU 132 monitors for the acceptance of an operation to select the printer to communicate with (hereinafter referred to as the "target printer") (hereinafter referred to as the "printer selection operation"). If the CPU 132 accepts the printer selection operation, it determines YES in S10 and proceeds to S12. The printer selection operation includes an operation to search for printers connected to LAN6. When the CPU 132 accepts this operation, it searches for printers connected to LAN6 and displays a list of printers connected to LAN6. The printer selection operation further includes an operation to select the target printer from one or more printers displayed in the list.

[0029] In S12, CPU 132 executes protocol determination processing. Protocol determination processing is the process of determining the communication protocol to be used for communication with the target printer (hereinafter referred to as "used protocol"). Specifically, CPU 132 sends a capability information request to the target printer. A capability information request is a command to request the transmission of capability information that includes information indicating the protocols supported by the target printer. When the target printer receives a capability information request from terminal device 100, it sends capability information that includes information indicating each protocol supported by the target printer to terminal device 100. The transmission of capability information requests and the reception of capability information are performed using SNMP.

[0030] For example, if printer 10A is the target printer, the target printer sends capability information to terminal device 100 that includes information indicating that the target printer supports SNMP. This capability information does not include information indicating that it supports HTTPS. If printer 10B is the target printer, the target printer sends capability information to terminal device 100 that includes information indicating that the target printer supports both SNMP and HTTPS. The CPU 132 uses the capability information to determine the protocol to be used. If the received capability information indicates that only SNMP is supported, the CPU 132 determines SNMP to be the protocol to be used. If the received capability information indicates that both SNMP and HTTPS are supported, the CPU 132 determines HTTPS, which has a high level of security, to be the protocol to be used. In this way, the CPU 132 can appropriately determine the protocol to be used according to the capability information of the target printer.

[0031] In S14, CPU132 determines whether the protocol used, as determined in S12, is SNMP. If the protocol used is SNMP (YES in S14), CPU132 proceeds to S20; otherwise, if the protocol used is not SNMP, i.e., HTTPS (NO in S14), it proceeds to S30.

[0032] In S20, CPU 132 executes SNMP processing. SNMP processing is the process of communicating between terminal device 100 and target printer according to SNMP. When S20 is completed, CPU 132 terminates the process shown in Figure 3.

[0033] In S30, CPU 132 executes HTTPS processing. HTTPS processing is the process of communication between terminal device 100 and target printer in accordance with HTTPS. When S30 is completed, CPU 132 terminates the process shown in Figure 3.

[0034] (SNMP processing; Figure 4) Referring to Figure 4, the SNMP processing performed in S20 of Figure 3 will be explained. In S50, CPU 132 monitors for acceptance of a configuration operation. A configuration operation in SNMP processing includes an operation to specify the information to be configured (for example, an IP address) and an operation to specify the modified string for the already specified information. If CPU 132 accepts the configuration operation (YES in S50), it determines that a configuration instruction has been obtained and proceeds to S52.

[0035] In S52, the CPU 132 sends a SET command to the target printer that includes the OID of the information specified in the configuration operation and the string specified in the configuration operation. When the target printer receives the SET command from the terminal device 100, it identifies the OID and string in the SET command. The target printer then associates the identified string with the identified OID and writes it as an MIB value to the target printer's management table (hereinafter referred to as the "target management table"). The target printer then sends a response command to the terminal device 100 that includes the OID of the information specified in the configuration operation and status information indicating that the writing of the MIB value is complete.

[0036] In S54, CPU132 receives a response command from the target printer. When S54 finishes, CPU132 returns to S50.

[0037] Furthermore, CPU 132 monitors S50 simultaneously with S60 to ensure that an acquisition operation is accepted. An acquisition operation in SNMP processing includes specifying the information to be acquired (for example, an IP address). When CPU 132 accepts an acquisition operation (YES in S60), it determines that an acquisition instruction has been received and proceeds to S62.

[0038] In S62, the CPU 132 sends a GET command containing the OID of the information specified in the acquisition operation to the target printer. When the target printer receives a GET command from the terminal device 100, it retrieves the MIB value associated with the OID included in the GET command from the target management table. The CPU 132 then sends a response command containing the retrieved MIB value to the terminal device 100.

[0039] In S64, the CPU 132 receives a response command from the target printer. The CPU 132 also displays the information in the response command on the display unit 114. This allows the user to learn about the settings of the target printer. When S64 finishes, the CPU 132 returns to S50.

[0040] In addition, CPU 132 monitors S50 and S60 simultaneously with S70 to ensure that a printer selection operation is accepted. If CPU 132 accepts the printer selection operation (YES in S70), it returns to S12 in Figure 3.

[0041] (HTTPS processing; Figure 5) Referring to Figure 5, the HTTPS processing performed in S30 of Figure 3 will be explained. In S90, CPU 132 monitors for acceptance of a configuration operation. The configuration operation in HTTPS processing includes specifying the information to be configured (e.g., an IP address), specifying the modified string for the already specified information, and entering authentication information. If CPU 132 accepts the configuration operation (YES in S90), it determines that a configuration instruction has been obtained and proceeds to S92.

[0042] In S92, the CPU 132 sends an HTTPS command containing authentication information to the target printer. When the target printer receives the HTTPS command from the terminal device 100, it performs authentication using the authentication information in the command. If the authentication is successful, the target printer sends a response command containing "OK" indicating successful authentication to the terminal device 100. If the authentication fails, the target printer sends a response command containing "NG" indicating failed authentication to the terminal device 100. The authentication in the HTTPS process follows either the HTTPS digest authentication method or the basic authentication method.

[0043] In S94, the CPU 132 determines whether or not it has received a response command containing the information "OK" from the target printer. If the CPU 132 receives a response command containing the information "OK" from the target printer (YES in S94), it proceeds to S96. If the CPU 132 receives a response command that does not contain the information "OK" from the target printer (NO in S94), it returns to S90. If the CPU 132 determines NO in S94, it displays information indicating that authentication failed on the display unit 114.

[0044] In S96, the CPU 132 performs a key exchange with the target printer. As a result, information within POST commands and response commands in subsequent communications between the terminal device 100 and the target printer (e.g., S98, S100) is encrypted. Because the information within the commands is encrypted in this way, the security level can be enhanced.

[0045] In S98, the CPU 132 sends a POST command to the target printer that includes the OID of the information specified in the configuration operation and the string specified in the configuration operation. When the target printer receives the POST command from the terminal device 100, it identifies the OID and string in the POST command. The target printer then writes the identified string as an MIB value associated with the identified OID to the target management table. The target printer then sends a response command to the terminal device 100 that includes the OID of the information specified in the configuration operation and status information indicating that the writing of the MIB value is complete.

[0046] In S100, CPU132 receives a response command from the target printer. Once S100 is complete, CPU132 returns to S90.

[0047] Furthermore, CPU 132 monitors S90 simultaneously with S110 to ensure that an acquisition operation is accepted. An acquisition operation in HTTPS processing includes specifying the information to be acquired (e.g., an IP address) and entering authentication information. When CPU 132 accepts an acquisition operation (YES in S110), it determines that an acquisition instruction has been received and proceeds to S112.

[0048] S112, S114, and S116 are the same as S92, S94, and S96, respectively. As a result, the information in the GET command and response command is encrypted in subsequent communications between the terminal device 100 and the target printer (e.g., S118, S120). In S118, the CPU 132 sends a GET command to the target printer that includes the OID of the information specified in the acquisition operation. When the target printer receives a GET command from the terminal device 100, it obtains the MIB value associated with the OID included in the GET command from the target management table. Then, the CPU 132 sends a response command to the terminal device 100 that includes the obtained MIB value.

[0049] In S120, the CPU 132 receives a response command from the target printer. The CPU 132 also displays the information in the response command on the display unit 114. This allows the user to know the settings of the target printer. When S120 finishes, the CPU 132 returns to S90.

[0050] In addition, CPU 132 monitors S90 and S110 simultaneously with S130 to confirm that a printer selection operation has been accepted. If CPU 132 accepts the printer selection operation (YES in S130), it returns to S12 in Figure 3.

[0051] (Specific cases) Next, referring to Figures 6 and 7, we will explain specific cases A to D that are realized by the processes shown in Figures 3 to 5.

[0052] (Case A; Figure 6) Referring to Figure 6, we will now explain Case A, in which a write operation is performed according to HTTPS.

[0053] When terminal device 100 receives a printer selection operation from the user in T10 to select printer 10B (YES in S10 in Figure 3), it sends a capability information request to printer 10B in T12, and in T14 receives capability information from printer 10B indicating that printer 10B supports SNMP and HTTPS. In this case, terminal device 100 determines that the security level of HTTPS is higher than the security level of SNMP and identifies HTTPS as the protocol to be used (NO in S12 and S14, S30).

[0054] Terminal device 100 accepts a configuration operation from the user at T20 (YES at S90 in Figure 5). The configuration operation in this case includes specifying the information to be written, "IP address", specifying the changed string "192.168.2.2" for "IP address", and entering authentication information. In this case, terminal device 100 sends an HTTPS command containing the authentication information to printer 10B at T22 (S92).

[0055] Printer 10B receives an HTTPS command from terminal device 100 at T22, and if authentication using the authentication information in the command is successful, it sends a response command containing the information "OK" to terminal device 100 at T24.

[0056] When terminal device 100 receives a response command containing the information "OK" from printer 10B at T24 (YES at S94), it performs an exchange of encryption keys with printer 10B at T30 (S96), and at T32 sends a POST command 200 corresponding to the setting operation at T20 to printer 10B (S98). Terminal device 100 identifies the OID ending in "4" from the information "IP address" specified in the setting operation at T20 and writes this information to POST command 200. Terminal device 100 also writes the string "192.168.2.2" specified in the setting operation at T20 as an MIB value to POST command 200.

[0057] When printer 10B receives a POST command 200 from terminal device 100 at T32, it determines that the command contains an OID ending in "4" and that the security information associated with the OID ending in "4" is "High". Printer 10B determines that a POST command in accordance with HTTPS has been received and that writing to MIB values ​​is permitted, and at T40, it writes the MIB value "192.168.2.2" from the command to the second management table 38B, associating it with the OID ending in "4". Next, at T42, printer 10B sends a response command 210 to terminal device 100 that contains the same OID as the OID ending in "4" of POST command 200 and the status information "success".

[0058] Terminal device 100 receives a response command 210 from printer 10B at T42 (S100). This completes the writing process.

[0059] (Case B; Figure 6) Next, referring to Figure 6, we will explain Case B, in which the retrieval process is performed in accordance with HTTPS. Case B is the state after Case A.

[0060] Terminal device 100 accepts an acquisition operation from the user at T110 (YES at S110). The acquisition operation in this case includes an operation to specify the information to be acquired, "remaining amount of consumables," and an operation to input authentication information. T112, T114, and T120 (S112-S116) are the same as T22, T24, and T30 in case A, respectively.

[0061] The terminal device 100 sends a GET command 220 to the printer 10B in response to the acquisition operation of T110 at T122 (S118). The terminal device 100 identifies the OID ending in "2" from the information "consumable amount" specified in the acquisition setting operation of T110 and writes this information to the GET command 220.

[0062] When printer 10B receives a GET command 220 from terminal device 100 at T122, it determines that the GET command 220 contains an OID ending in "2" and that the security information associated with the OID ending in "2" is "Low". Printer 10B determines that a GET command in accordance with HTTPS has been received and that transmission of MIB values ​​is permitted. In the second management table 38B, it identifies the MIB value "60" associated with the OID ending in "2", and at T124, it sends a response command 230 containing the identified MIB value "60" to terminal device 100.

[0063] When terminal device 100 receives a response command 230 from printer 10B at T124, it displays the MIB value "60" from the response command 230 at T126 (S120). This completes the acquisition process.

[0064] (Case C; Figure 7) Referring to Figure 7, we will now describe Case C, in which a write operation is performed according to SNMP.

[0065] When terminal device 100 receives a printer selection operation from the user at T210 to select printer 10A (YES at S10 in Figure 3), it sends a capability information request to printer 10A at T212, and at T214 receives capability information from printer 10A indicating that printer 10A supports SNMP. In this case, terminal device 100 identifies SNMP as the protocol to be used (YES at S12 and S14, S20).

[0066] Terminal device 100 accepts a setting operation from the user at T220 (YES at S50 in Figure 4). In this case, the setting operation includes specifying the information to be written, "IP address," and specifying the changed string "192.168.2.1" for the "IP address." In this case, terminal device 100 sends a SET command 300 corresponding to the setting operation at T220 to printer 10A at T222 (S52). Terminal device 100 identifies the OID ending in "4" from the information "IP address" specified in the setting operation at T220 and writes this information to the SET command 300. Terminal device 100 also writes the string "192.168.2.1" specified in the setting operation at T220 as an MIB value to the SET command 300.

[0067] When printer 10A receives a SET command 300 from terminal device 100 at T222, it determines that the command contains an OID ending in "4", and at T230, it associates the OID ending in "4" with the MIB value "192.168.2.1" within the command and writes it to the first management table 38A. T232 is the same as T42 in case A of Figure 6.

[0068] (Case D; Figure 7) Next, referring to Figure 7, we will explain Case D, in which the acquisition process according to SNMP is executed. Case D is the state after Case C.

[0069] Terminal device 100 accepts an acquisition operation from the user at T310 (YES in S60). The acquisition operation in this case includes specifying the information to be acquired, "consumable quantity". Terminal device 100 sends a GET command 320 to printer 10A at T312 in response to the acquisition operation at T310 (S62). Terminal device 100 identifies the OID ending in "2" from the information "consumable quantity" specified in the acquisition setting operation at T310 and writes that information to the GET command 320.

[0070] When printer 10A receives a GET command 320 from terminal device 100 at T312, it determines that the GET command 320 contains an OID ending in "2", identifies the MIB value "80" associated with the OID ending in "2" in the first management table 38A, and sends a response command 330 containing the identified MIB value "80" to terminal device 100 at T314.

[0071] When terminal device 100 receives a response command 330 from printer 10A at T314, it displays the MIB value "80" from the response command 330 at T316 (S64). This completes the acquisition process.

[0072] (Effects of Cases A to D) Before explaining the effects of Cases A to D, we will refer to Figure 8 to describe the processing performed by the comparative example terminal device 150. The comparative example terminal device 150 does not perform the protocol determination process S12 in Figure 3. Therefore, even if a printer 10B that supports SNMP and HTTPS is selected as the target printer, the terminal device 150 can send a request command in accordance with SNMP to the printer 10B.

[0073] Terminal device 150 accepts a printer selection operation at T410 to select printer 10B, and accepts a configuration operation from the user at T420. In this case, the configuration operation includes specifying the information to be written, "IP address," and specifying the changed string "192.168.2.2" for "IP address." In this case, terminal device 150 sends a SET command 410 in accordance with SNMP to printer 10B at T422. SET command 400 is the same as SET command 300 in Figure 7.

[0074] When printer 10B receives a SET command 400 from terminal device 150 at T422, it determines that the command contains an OID ending in "4", and determines in the second management table 38B that the security information associated with the OID ending in "4" is "High". Printer 10B determines that a SET command in accordance with SNMP has been received, determines that writing and sending MIB values ​​is prohibited, and does not write the MIB value "192.168.2.2" in the command to the second management table 38B. Next, printer 10B sends an ERROR command containing the status information "error" to terminal device 150 at T424. In addition, when printer 10B receives a GET command in accordance with SNMP containing an OID ending in "4" from terminal device 150, it sends an ERROR command containing the status information "error" to terminal device 150.

[0075] As described above, when printer 10B receives a SET command in accordance with SNMP from terminal device 150 (T422 in Figure 8), it may not write the MIB value to the second management table 38B. On the other hand, terminal device 100 in this embodiment sends a POST command in accordance with HTTPS to printer 10B (T32 in Figure 6). In this case, printer 10B writes the MIB value included in the POST command to the second management table 38B (T40). Therefore, the possibility that the MIB value will not be written to the second management table 38B can be reduced. Consequently, user convenience can be improved.

[0076] Furthermore, when printer 10B receives a GET command in accordance with SNMP from terminal device 150, it may not send the MIB value to terminal device 150. On the other hand, terminal device 100 in this embodiment sends a GET command in accordance with HTTPS to printer 10B (T122 in Figure 6). In this case, printer 10B sends the MIB value corresponding to the OID included in the GET command to terminal device 100 (T122 in Figure 6). Therefore, the possibility that the MIB value will not be sent to terminal device 100 can be reduced. Consequently, user convenience can be improved.

[0077] (Effects of this embodiment) According to the above configuration, terminal device 100 sends a SET command according to SNMP to printer 10A, which supports SNMP but not HTTPS, and sends a POST command according to HTTPS to printer 10B, which supports both SNMP and HTTPS. Therefore, terminal device 100 can send configuration commands (i.e., SET commands or POST commands) to printer 10 using the appropriate protocol.

[0078] Furthermore, the terminal device 100 sends an SNMP-compliant GET command to printer 10A, which supports SNMP but not HTTPS, and sends an HTTPS-compliant GET command to printer 10B, which supports both SNMP and HTTPS. Therefore, the terminal device 100 can send retrieval commands (i.e., GET commands) to printer 10 using the appropriate protocol.

[0079] (Correspondence) SNMP and HTTPS are examples of the "first protocol" and "second protocol," respectively. Printer 10A and Printer 10B are examples of the "first communication device" and "second communication device," respectively. The setting instructions obtained in S50 of Figure 4 and the setting instructions obtained in S90 of Figure 5 are examples of the "first setting instructions" and "second setting instructions," respectively. The SET command and POST command are examples of the "first setting command" and "second setting command," respectively. The OID included in the SET command in S52 of Figure 4 is an example of the "first OID." The MIB value included in the SET command in S52 of Figure 4 is an example of the "first setting value." The OID included in the POST command in S98 of Figure 5 is an example of the "second OID." The MIB value included in the POST command in S98 of Figure 5 is an example of the "second setting value." The first management table 38A and the second management table 38B are examples of the "first management information" and "second management information," respectively. The security information "High" in the second management table 38B is an example of "prohibited information" and "permitted information," respectively. The capability information of T214 in Figure 7 and the capability information of T14 in Figure 6 are examples of "first protocol information" and "second protocol information," respectively. The capability information request of T212 in Figure 7 and the capability information request of T12 in Figure 6 are examples of "first information request" and "second information request," respectively.

[0080] S52 in Figure 4 is an example of the process executed by the "first setting command transmission unit". S98 in Figure 5 is an example of the process executed by the "second setting command transmission unit".

[0081] The acquisition instruction obtained in S60 in Figure 4 and the acquisition instruction obtained in S110 in Figure 5 are examples of the "first acquisition instruction" and the "second acquisition instruction," respectively. The GET command following SNMP and the GET command following HTTPS are examples of the "first acquisition command" and the "second acquisition command," respectively. The response command in S64 in Figure 4 and the response command in S120 in Figure 5 are examples of the "first response command" and the "second response command," respectively. The OID included in the GET command in S62 in Figure 4 is an example of the "third OID." The MIB value included in the response command in S64 in Figure 4 is an example of the "third setting value." The OID included in the GET command in S118 in Figure 5 is an example of the "fourth OID." The MIB value included in the response command in S120 in Figure 5 is an example of the "fourth setting value."

[0082] S62 in Figure 4 is an example of the process executed by the "first acquisition command transmission unit". S64 in Figure 4 is an example of the process executed by the "first response command reception unit". S118 in Figure 5 is an example of the process executed by the "second acquisition command transmission unit". S120 in Figure 5 is an example of the process executed by the "second response command reception unit".

[0083] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples illustrated above. Modifications of the above embodiments are listed below.

[0084] (First variation) The "first protocol" and the "second protocol" may be a PJL (Printer Job Language) that does not use encryption and a PJL that uses encryption, respectively.

[0085] (Second variation) The second management table 38B of printer 10B does not need to contain security information.

[0086] (Third modified example) In S12 of Figure 3, the terminal device 100 may send a signal requesting the transmission of information indicating whether or not the target printer supports SNMP, and then send a signal requesting the transmission of information indicating whether or not the target printer supports HTTPS.

[0087] (Fourth Modification) Information regarding the communication protocols supported by the printer 10 may be stored in the memory 134 of the terminal device 100. For example, capability information is stored in the memory 134 when it is input by the user of the terminal device 100. In this modification, in S12 of Figure 3, the terminal device 100 determines the protocol to be used by utilizing the capability information in the memory 134 without sending a capability information request to the target printer. In this modification, the "first protocol information receiving unit," the "second protocol information receiving unit," the "first information request transmission unit," and the "second information request transmission unit" can be omitted.

[0088] (Fifth Modification) The printer 10 may be configured to periodically transmit capability information, or to transmit capability information when the printer 10 is powered on. That is, in this modification, the terminal device 100 receives capability information from the printer 10 before the command processing in Figure 3 is executed. In this modification, the terminal device 100 determines the usage protocol in S12 of Figure 3 without sending a capability information request to the target printer. In this modification, the "first information request transmission unit" and the "second information request transmission unit" can be omitted. In another modification, the terminal device 100 may send a capability information request to the target printer in S12 of Figure 3 only if the capability information of the target printer is not stored.

[0089] (Sixth variation) The "first communication device" and the "second communication device" are not limited to printers, but may be other devices such as scanners, facsimile machines, PCs, servers, etc.

[0090] (Seventh Modification) In the above embodiment, the CPU 132 executes programs 136 and 138 to realize the processes shown in Figures 3 to 5. Alternatively, any of the processes may be realized by hardware such as logic circuits.

[0091] Furthermore, the technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself.

[0092] Even if, in the claims of this patent application, each claim depends on only some of the claims, it is not limited to the claim being dependent only on those specific claims. To the extent that it is not technically contradictory, each claim may be dependent on other claims that were not dependent at the time of application. That is, the technologies of each claim can be combined in various ways as follows: (Item 1) A computer program for a terminal device, The aforementioned computer program controls the computer of the terminal device in the following parts, namely: A first setting command transmission unit transmits a first setting command in accordance with the first protocol to a first communication device when a first setting instruction is obtained for transmitting a setting command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first setting command includes a first OID (Object ID) of the MIB (Management Information Base) and a first setting value, and the first setting command is a command that requests that the first setting value be written to the first management information of the first communication device in association with the first OID, A second setting command transmission unit transmits a second setting command in accordance with the second protocol to a second communication device that supports the first protocol and the second protocol, when a second setting instruction is obtained for transmitting a setting command to a second communication device that supports the first protocol and the second protocol, wherein the second setting command includes a second OID of the MIB and a second setting value, and the second setting command is a command that requests that the second setting value be written to the second management information of the second communication device in association with the second OID, A computer program that functions as such. (Item 2) The security level of the second protocol is higher than that of the first protocol. The second management information of the second communication device stores, for each of the multiple OIDs of the MIB, the OID, the setting value, and the security information in association with each of them. The aforementioned security information is When a configuration command in accordance with the first protocol is received from an external device, prohibition information indicating that writing the configuration value corresponding to the configuration command is prohibited, When a configuration command in accordance with the first protocol is received from an external device, permission information indicating that writing of the configuration value corresponding to the configuration command is permitted is provided, A computer program as described in item 1, which shows one of the following. (Item 3) The aforementioned computer program further uses the computer, A first protocol information receiving unit that receives first protocol information indicating the protocols supported by the first communication device, A second protocol information receiving unit that receives second protocol information indicating the protocols supported by the second communication device, To make it function as, The first setting command transmission unit transmits the first setting command to the first communication device when the first setting instruction has been received and the received first protocol information indicates that the first communication device supports the first protocol but does not support the second protocol. The computer program according to item 1 or 2, wherein the second setting command sending unit transmits the second setting command to the second communication device when the second setting instruction has been obtained and the received second protocol information indicates that the second communication device supports the first protocol and the second protocol. (Item 4) The aforementioned computer program further uses the computer, A first information request transmission unit transmits a first information request to the first communication device requesting the transmission of the first protocol information, A second information request transmission unit transmits a second information request to the second communication device requesting the transmission of the second protocol information, and make it work The first protocol information receiving unit receives the first protocol information from the first communication device in response to the transmission of the first information request to the first communication device. The computer program described in item 3, wherein the second protocol information receiving unit receives the second protocol information from the second communication device in response to the transmission of the second information request to the second communication device. (Item 5) The first protocol mentioned above is SNMP (Simple Network Management Protocol), The second protocol is HTTPS (Hyper Text Transfer Protocol Secure), as described in any one of items 1 to 3. (Item 6) The aforementioned computer program further uses the computer, A first acquisition command transmission unit transmits a first acquisition command to the first communication device in accordance with the first protocol when a first acquisition instruction for transmitting an acquisition command to the first communication device is acquired, wherein the first acquisition command includes a third OID of the MIB, and the first acquisition command is a command requesting the transmission of a third setting value associated with the third OID in the first management information of the first communication device, When the first acquisition command is transmitted to the first communication device, the first response command receiving unit receives a first response command including the third setting value from the first communication device, A second acquisition command transmission unit transmits a second acquisition command to the second communication device in accordance with the second protocol when a second acquisition instruction for transmitting an acquisition command to the second communication device is acquired, wherein the second acquisition command includes a fourth OID of the MIB, and the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information, and a second setting command transmission unit When the second acquisition command is transmitted to the second communication device, the second response command receiving unit receives a second response command from the second communication device, which includes the fourth setting value. A computer program described in any one of items 1 through 5 that functions as such. (Item 7) A computer program for a terminal device, The aforementioned computer program controls the computer of the terminal device in the following parts, namely: A first acquisition command transmission unit transmits a first acquisition command in accordance with the first protocol to a first communication device when a first acquisition instruction is obtained for transmitting an acquisition command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first acquisition command includes a third OID (Object ID) of the MIB (Management Information Base), and the first acquisition command is a command requesting the transmission of a third setting value associated with the third OID in the first management information of the first communication device, When the first acquisition command is transmitted to the first communication device, the first response command receiving unit receives a first response command including the third setting value from the first communication device, A second acquisition command transmission unit transmits a second acquisition command to a second communication device that supports the first protocol and the second protocol when a second acquisition instruction is obtained for transmitting an acquisition command to the second communication device, wherein the second acquisition command includes a fourth OID of the MIB, and the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information of the second communication device, When the second acquisition command is transmitted to the second communication device, the second response command receiving unit receives a second response command from the second communication device, which includes the fourth setting value. A computer program that functions as such. (Item 8) The security level of the second protocol is higher than that of the first protocol. The second management information of the second communication device stores, for each of the multiple OIDs of the MIB, the OID, the setting value, and the security information in association with each of them. The aforementioned security information is When an acquisition command in accordance with the first protocol is received from an external device, prohibition information indicating that the transmission of a response command containing a setting value corresponding to the acquisition command is prohibited, A computer program as described in item 7, which indicates either permission information indicating that it is permitted to send a response command containing a setting value corresponding to the acquired command when a setting command in accordance with the second protocol is received from an external device, or (Item 9) The aforementioned computer program further uses the computer, A first protocol information receiving unit that receives first protocol information indicating the protocols supported by the first communication device, A second protocol information receiving unit that receives second protocol information indicating the protocols supported by the second communication device, To make it function as, The first acquisition command transmission unit transmits the first acquisition command to the first communication device when the first acquisition instruction has been acquired and the received first protocol information indicates that the first communication device supports the first protocol but does not support the second protocol. The computer program according to item 7 or 8, wherein the second acquisition command transmission unit transmits the second acquisition command to the second communication device when the second acquisition instruction has been acquired and the received second protocol information indicates that the second communication device supports the first protocol and the second protocol. (Item 10) The aforementioned computer program further uses the computer, A first information request transmission unit transmits a first information request to the first communication device requesting the transmission of the first protocol information, A second information request transmission unit transmits a second information request to the second communication device requesting the transmission of the second protocol information, and make it work The first protocol information receiving unit described above is: In response to the transmission of the first information request to the first communication device, the first protocol information is received from the first communication device. The second protocol information receiving unit described above is: The computer program according to item 9, which receives the second protocol information from the second communication device in response to the transmission of the second information request to the second communication device. (Item 11) The first protocol mentioned above is SNMP (Simple Network Management Protocol), The second protocol is HTTPS (Hyper Text Transfer Protocol Secure), as described in any one of items 7 through 10. [Explanation of Symbols]

[0093] 2: Communication system, 6: LAN, 10A: Printer, 10B: Printer, 34A: Non-volatile memory, 34B: Non-volatile memory, 36A: Volatile memory, 36B: Volatile memory, 38A: First management table, 38B: Second management table, 100: Terminal device, 112: Operation unit, 114: Display unit, 116: Communication I / F, 130: Control unit, 132: CPU, 134: Memory, 136: OS program, 138: Configuration application, 150: Terminal device

Claims

1. A computer program for a terminal device, The aforementioned computer program controls the computer of the terminal device in the following parts, namely: A first setting command transmission unit transmits a first setting command in accordance with the first protocol to a first communication device when a first setting instruction is obtained for transmitting a setting command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first setting command includes a first OID (Object ID) of the MIB (Management Information Base) and a first setting value, and the first setting command is a command that requests that the first setting value be written to the first management information of the first communication device in association with the first OID, A second setting command transmission unit transmits a second setting command in accordance with the second protocol to a second communication device that supports the first protocol and the second protocol when a second setting instruction is obtained for transmitting a setting command to the second communication device, wherein the second setting command includes a second OID of the MIB and a second setting value, the second setting command is a command that requests that the second setting value be written to the second management information of the second communication device in association with the second OID, the security level of the second protocol is higher than the security level of the first protocol, and the second management information of the second communication device includes, for each of the plurality of OIDs of the MIB, the OID and the setting The second communication device stores a value and security information in association, wherein the security information indicates either prohibition information indicating that writing a setting value corresponding to a setting command is prohibited when a setting command in accordance with the first protocol is received from an external device, or permission information indicating that writing a setting value corresponding to a setting command is permitted when a setting command in accordance with the first protocol is received from an external device, and the second communication device, when a second setting command is received from the terminal device, writes the second setting value regardless of whether the security information associated with the second OID in the second management information is the prohibition information or the permission information, the second setting command transmission unit, A computer program that functions as such.

2. The computer program further comprises the computer, When the second setting instruction is obtained, the authentication information transmission unit transmits authentication information to the second communication device, After the authentication information has been transmitted to the second communication device, if success information indicating that authentication using the authentication information has been successful is received from the second communication device, a processing execution unit executes an exchange process to exchange the encryption key with the second communication device. To make it function as, The computer program according to claim 1, wherein the second setting command transmission unit transmits the second setting command, including the encrypted second OID and the second setting value, to the second communication device after the exchange process is completed.

3. The aforementioned computer program further uses the computer, A first protocol information receiving unit that receives first protocol information indicating the protocols supported by the first communication device, A second protocol information receiving unit that receives second protocol information indicating the protocols supported by the second communication device, To make it function as, The first setting command transmission unit transmits the first setting command to the first communication device when the first setting instruction has been received and the received first protocol information indicates that the first communication device supports the first protocol but does not support the second protocol. The computer program according to claim 1, wherein the second setting command transmission unit transmits the second setting command to the second communication device when the second setting instruction has been obtained and the received second protocol information indicates that the second communication device supports the first protocol and the second protocol.

4. The aforementioned computer program further uses the computer, A first information request transmission unit transmits a first information request to the first communication device requesting the transmission of the first protocol information, A second information request transmission unit transmits a second information request to the second communication device requesting the transmission of the second protocol information, To make it function as, The first protocol information receiving unit receives the first protocol information from the first communication device in response to the transmission of the first information request to the first communication device. The computer program according to claim 3, wherein the second protocol information receiving unit receives the second protocol information from the second communication device in response to the transmission of the second information request to the second communication device.

5. The first protocol mentioned above is SNMP (Simple Network Management Protocol), The computer program according to claim 1, wherein the second protocol is HTTPS (abbreviation for HyperText Transfer Protocol Secure).

6. The aforementioned computer program further uses the computer, A first acquisition command transmission unit transmits a first acquisition command to the first communication device in accordance with the first protocol when a first acquisition instruction for transmitting an acquisition command to the first communication device is acquired, wherein the first acquisition command includes a third OID of the MIB, and the first acquisition command is a command requesting the transmission of a third setting value associated with the third OID in the first management information of the first communication device, When the first acquisition command is transmitted to the first communication device, the first response command receiving unit receives a first response command including the third setting value from the first communication device, A second acquisition command transmission unit transmits a second acquisition command to the second communication device in accordance with the second protocol when a second acquisition instruction for transmitting an acquisition command to the second communication device is acquired, wherein the second acquisition command includes a fourth OID of the MIB, and the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information, When the second acquisition command is transmitted to the second communication device, the second response command receiving unit receives a second response command from the second communication device, which includes the fourth setting value. A computer program according to claim 1, which functions as such.

7. A computer program for a terminal device, The aforementioned computer program controls the computer of the terminal device in the following parts, namely: A first acquisition command transmission unit transmits a first acquisition command in accordance with the first protocol to a first communication device when a first acquisition instruction is received for transmitting an acquisition command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first acquisition command includes a third OID (Object ID) of the MIB (Management Information Base), and the first acquisition command is a command requesting the transmission of a third setting value associated with the third OID in the first management information of the first communication device, When the first acquisition command is transmitted to the first communication device, the first response command receiving unit receives a first response command including the third setting value from the first communication device, A second acquisition command transmission unit transmits a second acquisition command to a second communication device that supports the first protocol and the second protocol when a second acquisition instruction is received for transmitting an acquisition command to the second communication device, wherein the second acquisition command includes a fourth OID of the MIB, the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information of the second communication device, the security level of the second protocol is higher than the security level of the first protocol, and the second management information of the second communication device stores each of the plurality of OIDs of the MIB in association with the OID, the setting value, and the security information. The security information includes either prohibition information indicating that when an acquisition command in accordance with the first protocol is received from an external device, the transmission of a response command including a setting value corresponding to the acquisition command is prohibited, or permission information indicating that when an acquisition command in accordance with the first protocol is received from an external device, the transmission of a response command including a setting value corresponding to the acquisition command is permitted. The second communication device includes a second acquisition command transmission unit that, when a second acquisition command is received from the terminal device, transmits a second response command including the fourth setting value to the terminal device, regardless of whether the security information associated with the fourth OID in the second management information is the prohibition information or the permission information. When the second acquisition command is transmitted to the second communication device, a second response command receiving unit receives the second response command from the second communication device, A computer program that functions as such.

8. The computer program further comprises the computer, When the second acquisition instruction is acquired, the authentication information transmission unit transmits authentication information to the second communication device, After the authentication information has been transmitted to the second communication device, if success information indicating that authentication using the authentication information has been successful is received from the second communication device, a processing execution unit executes an exchange process to exchange the encryption key with the second communication device. To make it function as, The computer program according to claim 7, wherein the second acquisition command transmission unit transmits the second acquisition command, including the encrypted fourth OID, to the second communication device after the exchange process is completed.

9. The aforementioned computer program further uses the computer, A first protocol information receiving unit that receives first protocol information indicating the protocols supported by the first communication device, A second protocol information receiving unit that receives second protocol information indicating the protocols supported by the second communication device, To make it function as, The first acquisition command transmission unit transmits the first acquisition command to the first communication device when the first acquisition instruction has been acquired and the received first protocol information indicates that the first communication device supports the first protocol but does not support the second protocol. The computer program according to claim 7, wherein the second acquisition command transmission unit transmits the second acquisition command to the second communication device when the second acquisition instruction has been acquired and the received second protocol information indicates that the second communication device supports the first protocol and the second protocol.

10. The aforementioned computer program further uses the computer, A first information request transmission unit transmits a first information request to the first communication device requesting the transmission of the first protocol information, A second information request transmission unit transmits a second information request to the second communication device requesting the transmission of the second protocol information, To make it function as, The first protocol information receiving unit receives the first protocol information from the first communication device in response to the transmission of the first information request to the first communication device. The computer program according to claim 9, wherein the second protocol information receiving unit receives the second protocol information from the second communication device in response to the transmission of the second information request to the second communication device.

11. The first protocol mentioned above is SNMP (Simple Network Management Protocol), The computer program according to claim 7, wherein the second protocol is HTTPS (abbreviation for HyperText Transfer Protocol Secure).

12. A terminal device, A first setting command transmission unit transmits a first setting command in accordance with the first protocol to a first communication device when a first setting instruction is obtained for transmitting a setting command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first setting command includes a first OID (Object ID) of the MIB (Management Information Base) and a first setting value, and the first setting command is a command that requests that the first setting value be written to the first management information of the first communication device in association with the first OID, A second setting command transmission unit transmits a second setting command in accordance with the second protocol to the second communication device when a second setting instruction is obtained for transmitting a setting command to a second communication device that supports the first protocol and the second protocol, wherein the second setting command includes a second OID of the MIB and a second setting value, and the second setting command is a command that requests that the second setting value be written to the second management information of the second communication device in association with the second OID. The security level of the second protocol is higher than the security level of the first protocol, and the second management information of the second communication device stores, for each of the multiple OIDs of the MIB, the OID, the setting value, and security information in association with the OID, the security information indicates either prohibition information indicating that writing the setting value corresponding to the setting command is prohibited when a setting command in accordance with the first protocol is received from an external device, or permission information indicating that writing the setting value corresponding to the setting command is permitted when a setting command in accordance with the first protocol is received from an external device, and the second communication device, when it receives the second setting command from the terminal device, writes the second setting value regardless of whether the security information associated with the second OID in the second management information is the prohibition information or the permission information, the second setting command transmission unit A terminal device equipped with the following features.

13. A terminal device, A first acquisition command transmission unit transmits a first acquisition command in accordance with the first protocol to a first communication device when a first acquisition instruction is received for transmitting an acquisition command to a first communication device that supports the first protocol but does not support the second protocol, wherein the first acquisition command includes a third OID (Object ID) of the MIB (Management Information Base), and the first acquisition command is a command requesting the transmission of a third setting value associated with the third OID in the first management information of the first communication device, When the first acquisition command is transmitted to the first communication device, the first response command receiving unit receives a first response command including the third setting value from the first communication device, A second acquisition command transmission unit transmits a second acquisition command to a second communication device that supports the first protocol and the second protocol when a second acquisition instruction is received for transmitting an acquisition command to the second communication device, wherein the second acquisition command includes a fourth OID of the MIB, the second acquisition command is a command requesting the transmission of a fourth setting value associated with the fourth OID in the second management information of the second communication device, the security level of the second protocol is higher than the security level of the first protocol, and the second management information of the second communication device stores each of the plurality of OIDs of the MIB in association with the OID, the setting value, and the security information. The security information includes either prohibition information indicating that when an acquisition command in accordance with the first protocol is received from an external device, the transmission of a response command including a setting value corresponding to the acquisition command is prohibited, or permission information indicating that when an acquisition command in accordance with the first protocol is received from an external device, the transmission of a response command including a setting value corresponding to the acquisition command is permitted. The second communication device includes a second acquisition command transmission unit that, when a second acquisition command is received from the terminal device, transmits a second response command including the fourth setting value to the terminal device, regardless of whether the security information associated with the fourth OID in the second management information is the prohibition information or the permission information. When the second acquisition command is transmitted to the second communication device, a second response command receiving unit receives the second response command from the second communication device, A terminal device equipped with the following features.

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