JPH0482351A - Data communication equipment - Google Patents

Abstract

PURPOSE:To operate plural communication modes smoothly by registering the communication mode, sending information including the operating mode to an opposite terminal equipment and deciding the communication propriety in the communication mode based on a received response. CONSTITUTION:An operation section 5 registers the communication mode and the registered communication mode is stored in a RAM 4. The communication mode stored in the RAM 4 is extracted and informed to a protocol management section 7 and a relating data link layer protocol 8-i is selected, an operating mode setting command is generated and the transmission is started. Upon the receipt of the operating mode setting command, a protocol management section 7 identifies the communication mode to discriminate whether or not the operating mode is capable of being set and when the setting is enabled, an acknowledge response (UA response) is sent, the operating mode is stored in the RAM 4 and the communication according to the stored operating mode is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data communication device that performs data link control, for example.

[Prior Art] Conventionally, HDLC (High
h Level Data Link Control
Procedure (high-level data link control means) is one of the standard methods in the data link layer of the OSI basic reference model defined by ISO, and is used in many data communication systems. HDLC has three operating modes: NRM (normal response mode), A
There are basic procedure class functions that support RM (asynchronous response mode) and ABM (asynchronous balanced mode), and additional functions that extend or limit these. By selecting the basic procedure class and additional functions, various functions can be created. A subset can be constructed.

l5DN (Integrated Service Digital Network), psPDN
(Public Packet Switched Network), C5PDN (Public Line Switched Network), etc., and is widely used in CCITT (International Telegraph and Telephone Consultative Committee) Recommendations X and 25/X.

L A P B (Link Acc
ess Protocol-Balanced),
LinkAccess Pr
occasion on the D-channel)
can be positioned as part of such a subset in HDLC.

Conventionally, when implementing a program for data link control in a data communication terminal, it was sufficient to implement only one fixed communication mode such as LAPB for a psPDN terminal. When implementing a program that performs data link control on a data communication device connected to an I5DN, it is currently recommended to use LAPD for the D channel and LAPB for the B channel. X, 25LAPB (modulo 8/modulo 128), X, 75LAPB (modulo 8/modulo 128), Q depending on the communication application.

921LAPD (modulo 8/modulo 128), DTE mode/DCE mode, 5LP (single link protocol)/MLP (multilink protocol)
It is expected that there will be a need to implement multiple communication modes, such as:

[Problems to be Solved by the Invention] However, in conventional data communication devices connected to 15DN, only one communication mode is usually implemented for the B channel, so it is difficult to match the communication mode with the communication mode of the communicating party. There was a constraint that communication could not be performed without doing so. Furthermore, even if the B channel has multiple communication modes, there is no means to select and switch between them when making a call, or a means to identify the communication mode when receiving a call. There was a drawback that the communication mode did not match and communication could not be performed.

An object of the present invention is to provide a data communication device that can smoothly operate a plurality of communication modes compatible with increasingly complex communication applications.

[Means for Solving the Problems] In order to solve the above problems and achieve the objectives, a data communication device according to the present invention has the following configuration. That is, in a data communication device that performs communication in an operation mode according to a communication mode in a data link layer, a registration means for registering the communication mode, a storage means for storing the communication mode registered by the registration means, and a storage means for storing the communication mode registered by the registration means. generation means for generating an operation mode according to a stored communication mode; transmission means for transmitting information including the operation mode generated by the generation means to a partner terminal; and a transmission means corresponding to the operation mode of the information transmitted by the transmission means. The present invention is characterized by comprising: receiving means for receiving a response received by the receiving means; and determining means for determining whether communication is possible in the communication mode corresponding to the operation mode based on the response received by the receiving means.

Preferably, in a data communication device that performs communication in an operation mode according to a communication mode in a data link layer, a registration means for registering a plurality of the communication modes, and a storage means for storing the communication modes registered by the registration means; selection means for selecting one communication mode from among the communication modes stored by the storage means,
When setting an operation mode according to the communication mode selected by the selection means with a partner terminal, if the operation mode according to the communication mode is not possible, instructing the selection means to switch to another communication mode. It is characterized by

Further, preferably, in a data communication device that performs communication in an operation mode according to a communication mode in a data link layer, a receiving means for receiving information including the operation mode, and a corresponding one of the operation modes of the information received by the reception means The present invention is characterized by comprising an identification means for identifying a communication mode to be used, a judgment means for judging whether communication is possible in the communication mode identified by the identification means, and a transmission means for transmitting a response based on the result determined by the judgment means. shall be.

[Operation] In such a configuration, the registration means registers the communication mode,
The storage means stores the communication mode registered by the registration means, the generation means generates an operation mode according to the communication mode stored by the storage means, and the transmission means transmits information including the operation mode generated by the generation means to the other terminal. The receiving means receives a response corresponding to the operating mode of the information transmitted by the transmitting means, and the determining means communicates in a communication mode corresponding to the operating mode based on the response received by the receiving means. Decide whether or not to proceed.

Further, the registration means registers a plurality of communication modes, the storage means stores the communication modes registered by the registration means, and the selection means selects one communication mode from among the communication modes stored by the storage means, and When setting the operation mode according to the communication mode selected by the selection means with the terminal, if the operation mode according to the communication mode is not possible, the selection means is instructed to switch to another communication mode.

Furthermore, the receiving means receives information including the operating mode, the identifying means identifies a communication mode corresponding to the operating mode from the information received by the receiving means, and the determining means determines whether communication is possible using the communication mode identified by the identifying means. 2, and the transmitting means transmits a response based on the result determined by the determining means.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a data communication device in this embodiment. In the figure, reference numeral 1 indicates a data communication device (this device) that performs data link control in this embodiment. 2 is a central processing unit (hereinafter referred to as rCPUJ) that controls all the circuit elements constituting this device 1; 3 is a central processing unit (hereinafter referred to as rCPUJ) that controls all the circuit elements constituting this device 1; 4 is a RAM which is used as a work area to store communication modes etc. as will be described later; 5 is a display unit which displays keys for registering communication modes etc. and operating status. Each figure shows an operating section with a

6 is a protocol control unit that controls various data link layer protocols; a protocol management unit 7 that selects a communication mode when making a call and identifies a communication mode when receiving a call;
It is composed of a data link layer protocol group 8 including various data link layer protocols. The data link layer protocol group 8 consists of data link layer protocols 8-1 to 8-n. Reference numeral 9 indicates a line control unit corresponding to each data communication line, and 10 indicates a communication line for transmitting communication data such as image data.

The operation of the data communication device 1 having the above configuration is shown in FIGS.
This will be explained below with reference to FIG.

FIG. 2 is a flowchart explaining the communication mode registration operation by the CPU 2 of this embodiment, and FIG.
FIG. 4 is a flowchart explaining the data link setting operation at the time of a call by U2, and FIG.
2 is a flowchart illustrating the operation of data link setting when a call is received.

First, when registering a communication mode, the flowchart in FIG. 2 is applied.

This communication mode registration may be performed as a default setting when the device 1 is installed, or may be performed each time a call is made. As shown in FIG. 2, in step S21, the communication mode is registered from the operation unit 5, and the communication mode registered in step S22 is stored in the memory, that is, the RAM 4.
and end the process. Here, the communication mode to be registered is related to the data link layer, for example, D
TE/DCE, X, 25/X, 75/Q, 921, SL
It consists of various selection items such as P/MLP, modulo 8/modulo 128.

Next, when the device 1 makes a call, the flowchart in FIG. 3 is applied.

That is, as shown in FIG. 3, in step S31, the communication mode stored in the RAM 4 is retrieved and notified to the protocol management unit 7, and the protocol management unit 7 selects the corresponding communication mode from among the various data link layer protocol groups 8. Data link layer protocol 8-i (1≦i≦n) is selected. Selected data link layer protocol 8
-i, an operation mode setting command is generated according to the communication mode in step S32, and transmission of the operation mode setting command is started in step S33.

For example, the communication mode is DTE-X, 75LAPB-3L
In the case of P.modulo 8, the operation mode setting command is SABM (control section = 3FH) at address B (address section -01H).

Next, in step S34, a response (UA response) to the transmitted operation mode setting command
If a response is received, communication is started in step S35, and the process ends.

Next, in this device 1, the operation when receiving a call is performed in the fourth step.
This will be explained with reference to the flowchart shown in the figure.

First, in step S61, if an operation mode setting command is received, in step S62, the protocol management section 7 identifies the communication mode from the received operation mode setting command.

For example, the address part of the operation mode setting command is 01H.
(address B), control section is SABM (3FH)
Then, the communication mode is DCE・X, 75LAPB-3
LP-(-Juro 8.

Furthermore, in step 363, the protocol management section 7
Then, it is determined whether communication can be performed in the identified communication mode described above, that is, whether the operation mode can be set. If the operation mode is not settable, in step S64, the received operation mode setting is Either ignore the command or send a response rejection response (DM response) and end the process. If the operation mode can be set, a response (tJA response) is transmitted in step S65, the operation mode is stored in the RAM 4, communication according to the stored operation mode is started in step S66, and the process is ended. do.

As explained above, according to this embodiment, the communication mode to be used is registered in advance, and when transmitting the operation mode setting command in the data link layer, the operation mode is set according to the registered communication mode. By operating the system to send commands, the same program can be easily applied to communication system environments with different communication modes, such as packet-switched networks and circuit-switched networks, and it is also possible to switch communication modes when making a call. becomes.

As a modification, if no response is received in step S34 described above, it is also possible to switch to another communication mode. In this case, the registration of the communication mode is the same as in the above-mentioned embodiment (the same process is performed and the flowchart in FIG. 2 is applied. However, at this time, a plurality of communication modes are registered. 5 is applied instead of FIG. 3, and when a call is received, the above-mentioned FIG. 4 is applied.Of course, FIG.
The program according to the flowchart shown in the figure is stored in the ROM 3 and has a similar device configuration.

FIG. 5 is a flowchart illustrating the operation when the communication mode is switched when the CPU 2 makes a call according to a modification of the present embodiment, and FIG. 6 shows the sequence when the communication mode is switched when the CPU 2 makes a call according to the present embodiment. It is a diagram.

That is, as shown in FIG. 5, in step S41, it is checked whether all the communication modes stored in the RAM 4 have been used, and in step S42, the communication modes stored in the RAM 4 are checked.
extracts a communication mode that is not yet used from among the communication modes stored in the , and notifies it to the protocol management section 7;
The protocol management unit 7 selects a corresponding data link layer protocol 8-i from the various data link layer protocol groups 8. In the selected data link layer protocol 8-i, an operation mode setting command is generated according to the communication mode in step 343, and transmission of the operation mode setting command is started in step S44.

Next, in step S45, a response (UA response) to the transmitted operation mode setting command
Wait for the response, and if a response is received, step S
Communication is started in step 46, and the process ends.

On the other hand, if the response is not received in step S45, the process returns to step 541 and the above-described process is repeatedly executed in a different communication mode.

As shown in FIG. 6, in the above-mentioned processing sequence for switching the communication mode at the time of a call, if the communication mode is DTE-X, 75LAPB-3LP/modulo 128 in the first attempt, the communication mode is DTE-X in the second attempt. is DTE
-X, 75LAPB-SLP modulo 8 is shown.

In order to select the communication mode described above, it is preferable to preset a priority order for the communication modes at the time of registration.

In this way, by setting multiple communication modes to be used depending on each communication application used by the user, and selecting a communication mode different from the communication mode of the other party with which to communicate, the transmitted operation mode If the setting command is not accepted, the operation mode is switched to another communication mode and the operation mode setting command is sent. Therefore, it is possible to easily communicate with a communication partner, and the problem of not being able to communicate due to mismatching communication modes, especially when making a call, can be solved.

Furthermore, by automatically identifying the communication mode specified by the received operation mode setting command and operating to perform communication in the specified communication mode, it can be used in a communication system environment where multiple communication modes coexist, such as I5DN. On the other hand, it is possible to easily communicate with a partner in a different communication mode, and it is possible to solve the problem of not being able to communicate due to inconsistency in communication modes, especially when receiving a call.

Now, in the embodiment described above, the operation mode setting command is transmitted at the time of transmission, and the operation mode setting command is received at the time of reception, but the present invention is not limited to this. For example, in packet switching, it is sufficient to send an operation mode setting command and set a data link in advance before receiving a call.

Further, the communication mode classification method is not limited to the above-described embodiment, and any classification method may be used as long as it can uniquely determine the data link layer protocol.

Furthermore, various data link layer protocols 8-i are
It may be one control program or multiple control programs.

The above-mentioned data communication device is 15DN, PSP
Needless to say, the present invention can be applied to various data communication networks such as DN and C5PDN.

[Effects of the Invention] As described above, according to the present invention, it is possible to smoothly operate a plurality of communication modes compatible with increasingly complex communication applications.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the data communication device in this embodiment, FIG. 2 is a flowchart explaining the communication mode registration operation by the CPU 2 in this embodiment, and FIG. 3 is a block diagram of the data communication device in this embodiment.
FIG. 4 is a flowchart illustrating the data link setting operation by the CPU 2 of this embodiment when a call is received; FIG. FIG. 6 is a flowchart illustrating the operation when switching the communication mode when making a call by the CPU 2 of this embodiment. FIG. In the figure, 1... data communication device, 2... CPU, 3...
...ROM, 4...RAM, 5...operation unit, 6...
・Protocol control section, 7... Protocol management section, 8.
. . . data link layer protocol group, 9 . . . line control unit, 10 . . . data communication line. Figure 1 Figure 3 Figure 5 Figure 4 Figure

Claims (3)

[Claims] (1) A data communication device that performs communication in an operation mode that follows a communication mode in a data link layer, comprising: a registration means for registering the communication mode; a storage means for storing the communication mode registered by the registration means; and the storage means. generating means for generating an operational mode according to the communication mode stored by the transmitting means; transmitting means for transmitting information including the operational mode generated by the generating means to a partner terminal; A data communication device comprising: receiving means for receiving a corresponding response; and determining means for determining whether communication is possible in the communication mode corresponding to the operation mode based on the response received by the receiving means. (2) In a data communication device that performs communication in an operation mode according to a communication mode in a data link layer, a registration means for registering a plurality of the communication modes, a storage means for storing the communication modes registered by the registration means, and the storage. selection means for selecting one communication mode from among the communication modes stored by the means; when setting an operation mode with a partner terminal according to the communication mode selected by the selection means; A data communication device characterized in that, when the operation mode according to the communication mode is not possible, the selection means is instructed to switch to another communication mode. (3) In a data communication device that performs communication in an operating mode according to a communication mode in a data link layer, a receiving means for receiving information including the operating mode, and communication corresponding to the operating mode of the information received by the receiving means. It is characterized by comprising an identification means for identifying a mode, a judgment means for judging whether communication is possible in the communication mode identified by the identification means, and a transmission means for transmitting a response based on the result determined by the judgment means. Data communication equipment.