JPS61161569A - Command interchange control system in plural electronic device systems - Google Patents

Abstract

PURPOSE:To control exclusively a command interchange in an overall data processing system by permitting command interchange only when code-classified stored contents in a storage means indicates that the interchange is not performed. CONSTITUTION:A controller 100 receives concentratedly commands from all data processors E and peripheral devices P. Codes different from each other are assigned to devices E and P respectively. When the controller 100 receives an interchange part message, the controller 100 permits a command interchange and rewrites stored contents to indicate that an interchange is performed only when code-classified stored contents in a storage means F indicate that an interchange is not performed; and when the controller 100 receives an interchange end message, the controller rewrites stored contents to indicate that an interchange is not performed.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention provides a peripheral NW commonly provided for a plurality of data processing devices, particularly an ECR, and a peripheral NW such as a printer, a floppy device, a tape cassette device, etc.
CRT device, card league. The present invention relates to a method for exclusively controlling the exchange of commands between data processing devices in a plurality of electronic device systems including mark leagues and between data processing devices and peripheral devices.

[Prior art and its problems]

In the technical field mentioned above, especially in the field of ECR to which the present invention is suited, as its application field expands not only to stores and supermarkets but also to relatively large corporate entities such as large cafeterias and hotels, its performance and functions will also increase. As is well known, such ECs are transforming from sophisticated and very simple ones to ones with more advanced functions such as PLU functions.
R is a data processing device adapted to a PO8 device,
Although processing speed and storage capacity are improving, in many cases it is difficult to link them together, and as in the case of the hotel mentioned above, stand-alone ECRs are installed separately for the front desk, cafeteria, tea room, shop, etc. Usually, they are installed or expanded one after another, and in order to create a comprehensive POS system, it is necessary to introduce a full-fledged but expensive computer system, which raises the problem of high installation costs including software. Therefore, those who have introduced ECRs are demanding an ECR that can be easily expanded as needed, that can be linked together, and that can form a comprehensive POS system. The problem with the overall POS system configuration is not only the cooperation between ECRs but also the cooperation with their peripheral devices. Conventionally, peripheral devices such as printers and CRT devices were
It was often set up exclusively for However, for example, there are many sales points within the hotel, such as Japanese food, Western restaurants, and tea rooms, and there are several cooking rooms.
To meet the requirements of the dedicated peripherals sold in each version, a shared peripheral must be provided for multiple ECRs. Conventionally, in order to meet such requests, the peripheral device on the command receiving side was provided with a function of exclusive control when request commands such as print or display were simultaneously received from a plurality of ECRs to a common peripheral device. However, as is well known, all of these peripheral devices are relatively simple and single-function devices, and it is necessary to add complex control functions to ensure that they have the above-mentioned exclusive functions. Therefore, the price is high, and the exclusive control circuit needs to be changed each time the ECR sharing conditions change, so it cannot be used as a general shared peripheral device.

[Purpose of the invention]

In view of the above-mentioned circumstances, the main object of the present invention is to exclusively control the command exchange within the system when a comprehensive data processing system is configured by multiple data processing devices including shared peripheral devices. The goal is to find a suitable method. It is an object of the present invention to enable the present invention to be used exclusively for a molding apparatus or for use in common with a plurality of data processing apparatuses.

[Key points of the invention]

According to the present invention, the above-mentioned object is to allocate a different code to each electronic device as a command AC control system in a system of multiple electronic devices as described at the beginning, and to assign a different code to each electronic device while transmitting a command to the electronic device using the code. A command exchange side that is equipped with a storage means to centrally accept command transmission paths from each electronic device? 11 devices are provided, and the command source electronic device sends an AC start message and an AC end message including the code of the command destination electronic device to the command AC control device before and after the command exchange starts and ends, respectively, to perform command AC control. On the device side, upon receiving the communication start message, command communication is permitted only when the code-specific memory contents in the storage means indicate that communication is not in progress, and the memory contents are rewritten during communication. For the first time when the communication end message is received. This is achieved by rewriting the memory contents during non-interchange. The basic configuration example of the above method of the present invention is schematically shown in the first example.
As shown in the figure. In the upper part of the figure, a plurality of data processing devices E O+ E l + E i + E j are shown, all of which are ECRs, for example, while in the lower part of the figure peripheral devices Pk, Pi are shown. These data processing devices and peripheral devices are connected to an input/output port 110 of a command AC control device 100 (hereinafter simply referred to as a control device) shown in the center of the figure. As seen in Figure 2 below, this pattern is a so-called star-shaped connection with the control device 100 at the center, and the control device 100 connects to all the data processing devices E and its surroundings! Centrally accepts commands from a and p. Additionally, each device is assigned a different code, such as a serial number or consecutive number code, and in Figures 1 and 2, this code is assigned within the frame of devices E and P. 1 shown in
1.1. i, i, ni, I 7 + 1,600 stings 1, Sue whistle 9M's 5-event The processing device EO comes with a dedicated peripheral device PO, but this code is represented by the data processing device EO, so No other code was taken. This data processing device EO may be connected to another data processing device E, for example.
1. The EitEj is a parent device that serves as a child device, and the peripheral device PO attached to it is an external storage device such as a floppy device, which stores important programs and data needed by the parent device and child devices. It is a common peripheral device. The input/output ports 110 of the control device 100 described above have input/output circuits 11i (i = 0.l, i, j, 1) corresponding to the devices E and P whose codes are taken as above. For example, data processing device Ej from which code j has been removed is connected to input/output circuit 11j of input/output port 110 via connection cable j. Note that these input/output circuits 11i are the same regardless of whether the corresponding device is a data processing device E or a peripheral device P, and any type of device can be connected to a specific input/output circuit 11i. Can be selectively connected. In addition, each input/output circuit 11i has a pair of input circuits and output circuits each consisting of gates and 7 channels, as shown by the chain line in the center, and two electric wires in the corresponding connection cable-1. are connected to them respectively. The storage means F shown in the center of the control device 100 surrounded by a dashed line is an area for storing flags set in a RAM, for example, and the number of flags Fi corresponding to the code i described above is It has an area that can store (i=o, l, i. j+, l). Now, when sending a command from the data processing device Ej corresponding to code i to the peripheral device Pk corresponding to code k to cause the peripheral device Pk, which is a printer, for example, to perform a printing operation, an arrow is drawn below the data processing device Ei. As shown, first, an AC start message MS containing a code k is sent to the control device 100. At this time, if the peripheral device Pk that is the destination of the command is not yet operating according to a command from any data processing device E, the corresponding flag Fk is O, so the control device 100 confirms this and then sets the flag Fk. A flag value is set to indicate that communication is in progress. This flag value may most simply be the rlJ value, but in the illustrated example, the above-mentioned AC start message MS also includes the sender code i, and this sender code i is set as the flag value. Also, as can be easily understood, the way to set this flag is to set [lu for both flags Fi and Fk corresponding to the source code i and destination code k. The destination code is stored in the control device 100, and the device with the code number i and the device with the code number can be connected by opening the gates or latches of the output circuits seen from the control device of the input/output circuits 11i and llk described above, for example. Allow command exchange between. Command message M following the exchange start message MS
1 and M2 are, for example, messages instructing the above-mentioned printing, and include data indicating the printing contents. Also, the command message is not limited to once, but is issued multiple times as necessary, and these command messages are issued each time. IIJ2 is transmitted to the peripheral device f'k as shown, and the command is executed. When the execution of each command is completed, the peripheral device Pk sends an execution end message e1. e2 is sent to the data processing device Ei in the opposite path to the previous one, and the data processing device Ei side issues the next command message after receiving the execution completion message. When the data processing device ll E i has sent all commands to the peripheral device Pk and has received the final execution end message for it, it sends an AC end message ME to the control device ff 100 . This exchange termination message ME includes at least the destination code k as before, and usually also includes the source code i, and in response to this, the control device 100 changes the flag value of the flag Fk, for example, to By returning to 0 indicating , permission for command exchange between the device with code i and the device with code i is canceled. During the command exchange between code i and code i, if an exchange start message MS is issued from the data processing bag ffEj of code j to the peripheral device Pk as shown by the chain line in the figure, the control device ff1oo transmits the message. Since the flag Fk corresponding to the command execution interval Ak between the MS code i and the command execution interval is not 0, which indicates that no exchange is in progress, the start of command exchange is not permitted, thereby achieving the intended exclusive control. is followed. As can be seen from the above description, in the method of the present invention, the communication start message MS and the communication end message M
E is only given to the control device 100 and is not transmitted to the destination device. Therefore, there is no need to provide the destination device 1, for example, a peripheral device, with an additional circuit for exclusive control as in the prior art, and an idle device can be used as a general-purpose peripheral device. Also as mentioned above. While commands are being exchanged between codes t and t, commands can be exchanged between twos 11 and 1 that are completely unrelated to them. However, since the bus configuration and its control within the control device 100 become somewhat complicated, a system that uses an ECR for the data processing device EE is not equipped with such a so-called multiple data exchange function. It is better not to have the control device 100n)iii;
#49j-MrhM/%nY? MM++'? This is desirable for reducing M. Figure 3 shows the same pattern of command transmission between the master device with code number O as shown in (al) and the peripheral device PO attached exclusively to it but shared by all data processing devices E as mentioned above. As can be easily seen, in this case, neither the AC start message MS nor the AC end message ME are needed, and the main unit EO is connected to the old command message and M2 around it. Give job Jl to device PO. Execution 1 of J2 For example, data 01.02 may be read and the next command message may be issued after each execution end message e is received. Figure 4 similarly shows how commands are exchanged between data processing devices over time;
Commands are exchanged between the data processing bags [E[, Ej] shown in FIG. As shown in Figure 1), first, the code i
An alternating current start message MS is issued from the device Ei, and in response to this, the control device 100 sets the code i as the flag value in the flag Fj corresponding to the code j, and then sets the permission signal R.
Return DY to the device with code l. A command message CMI is then issued to device Ej with code j through control bag f 100, and after job J1 is executed therein, an execution completion message e is returned to device Ei. At this time, even if the AC start message MS is issued from 1llEo to device Ej, is there any control? Since the flag Pj is already set to i, the B device 100 sends the prohibition message PR without permission.
Return H to the parent unit EO. After that, the command message CM2 is issued from the device Ej, and the control device 100 that received this has already permitted command exchange between codes j+J, so the command message CM2 is transmitted to the device Ei without issuing a prohibition message. Job J2
is executed and an execution end message e is returned to device Ej. When the AC end message ME is issued from the device Ej, the control? 11 device E100 thereby sets the flag FjO.
After returning the value to 0, a communication permission cancellation message OFF is sent to the device Ei. In addition, in this process, instead of setting i to flag Fj, the flag Fi shown to the left of it may be set to the logical value "1" as well, and the same command exchange permission and prohibition operations will be obtained. It is clear that it is possible to

[Embodiments of the invention]

Hereinafter, the best embodiment of the system of the present invention will be described in more detail with reference to FIG. 5 and subsequent figures. Figure 5 shows an example of the configuration of a device group to which the method of the present invention is applied, taking as an example a hotel or a large dining room.
The area divided by m indicates the area within the facility where each device is installed. The illustrated devices are connected in a star shape as described above, centering on the control device f100 shown on the left side of the figure, and the data processing device, that is, the master unit [10 of the ECR in the figure] is placed, for example, at the front, and The main unit includes a floppy device PO as a shared peripheral device attached to the main unit, and a printer (not numbered). E as a slave unit shown below
The CR system is installed in a restaurant, for example, and is equipped with a slip printer for making slips for waitresses to order. Furthermore, the ECR shown below
The device is equipped with a printer for creating receipts, etc., if necessary. Tape cassette device P shown on the left
K and printer pt are shared peripheral devices directly connected to the control device 100, and store programs and data read from the tape cassette device Pk.
The printer pt is an external storage device that is placed in the same section as the control device 100, and the printer PT is installed in the cooking room, for example, and prints out orders received from customers in the prefecture where the ECR device is installed, so that the cook can prepare the food. It is a kitchen printer that commands to start. These ECR device locations shown in the figure, ε1+EJ+peripheral equipment P
k. PI etc. have connection cables -〇, old, Wj, Wk,
The connection receptacle 1 to the control device 100 by M1 etc.
Each receptacle 120 can be connected to any ECR device or peripheral device, as described above. FIG. 6 shows an example of the internal configuration of the control device 100, and shows E not shown on the left and right sides of the control device 100 surrounded by a dashed line, and not shown in the receptacles 121 to 126.
CRg devices E to E3 and peripheral devices P4 to P6 shown on the right side of the figure are connected to Fi tr via connection cables, respectively.
The i state is shown. Note that this figure only shows two lines for command and data transmission within the connection cable. As shown in the figure, the control device 100 itself is a microcomputer, and as usual, a CP
A flag area F as a storage means in the present invention includes UIOI, ROM2O3゜RAM 103, an address bus 104 and a data bus 105 that connect them.
is set in RAM 103. The data transmission lines leading to the aforementioned receptacles 121 to 126 come out from input/output circuits 111 to 116, respectively, and the input/output circuits are connected to the data bus 105 and are connected to the decoder 106 by the address bus 104 and via the control line 107. controlled. The input/output circuits 111 to 112 each consist of a pair of an input circuit 111a and an output circuit 111b, as shown in detail for the input/output circuit 111. For example, the former is a simple gate circuit, and the latter is a latch circuit. Is that okay? avA 107 enables or enables the circuit specified by the address on address bus 104. FIG. 7 shows the general format of message M that control device 100 accepts or transmits via this input/output circuit. The same figure (a, device i, e.g.
A message MA is issued from CR specifying a device k, for example, a peripheral device, and there is a normal opening section MO at the beginning in the direction of the arrow in the figure, followed by a destination code section 1'LD specifying the destination device k. This is followed by a source code section indicating the source device k. The next command part MC is message M
A command that is the main body of a message MA and indicates the characteristics of the message MA. In other words, is it an exchange start message MS or an exchange end message? + [! In this case, there is a command that indicates the start or end. In the case of the above-mentioned command messages M1 and M2, the destination device W
A command is entered that specifies the zip that tk should perform. Furthermore, the data section following this includes data and programs necessary for the job to be performed on destination device k, for example, if destination device k is a printer, content data to be printed is attached. Of course, Mesosage MA
If it is an exchange start message MS or an exchange end message ME, it is not necessary to add this data part MP because the destination or source of the message is the control device 100. The message MB shown in the same figure (bl) is (
A reply message to the message gate ^ shown in al, for example, the above-mentioned end message s, e1. e2, etc., whose structure is the same as before, but the code k that was in the destination code section MO in message MA is changed to the sender code section Ml in message MB, and to the sender code section old in message MA. In the message MB, the contained code i is stored in the destination code section MD as shown by the arrows in the figure. Also, command department MC
The input commands include, for example, a command to report the completion of the specified zip from 'A W i, but at the same time, a command to request a different job from the installation ffk side to the installation i is input. It is possible that it may be done. In addition, in the data part MP in the case of reply message 2, v
Next, the control device 100 in the method of the present invention will be described with reference to FIG. 8 showing the operation flow of the CPU 101 of the control device 100. The main operation will be explained.This flowchart shows that, as shown in FIG. This corresponds to the value a, and for ease of understanding, the code of the transmitting device is depicted as i and the code of the destination device is k.In the first step Sl, the control device 100 sends a message. M
is received, and this message M can be an exchange start message MS, an exchange end message ME, a command message Ml, M2, or an execution end message el, e2, etc. according to the contents of the command part MC, but in any case, the opening part MO, Destination code section? 1I), the source code section identifies the code of the destination device of the command exchange and the code i of the source device. In the following step s2, it is determined whether it is the destination device or not, and if it is zero, the process jumps to step S4, but if the flag value has already been set, then in step S3 the flag value is -ff&ed with the code i of the source device. It is determined whether or not. If the command exchange has not yet started, the determination result in step S2 is positive, so the process jumps to step S4, where it is determined whether the command part MC of the received message M is the exchange start command S, and as a result, the flow is as follows. The flow moves to the right column from step S5 onwards. In step S5, the code i of the source device is set in the flag Fk corresponding to the code k of the destination device, and in the next step S6, for example, the output circuit in the input/output circuit 110 corresponding to these two codes i and k is set. In step S7, the enable signal RDY is sent to the code i through the enabled output circuit.
This completes the preparation for command exchange between T and T, and returns the flow to step Sl. When a message M, which is a command message Ml or M2, is sent from the device with code i to the device with code i, the control device 100 receives it in step S1 as before, but this time the flag Fk has already been set to i. is set up, so the flow is from step knob S2 to step S3 below.
The determination result in step S3 is also positive, and in step S4, the contents of the command part MC of the message M are different from the AC start command S, so the flow is as shown in step S below.
Move on to 8. In step S8, the contents of the command section are compared with the AC end command E, but if the message M is a command message, the judgment result is negative, so the flow goes to step S9 below and receives the message from the device with code i. The message is transferred directly to the coded device. However, in terms of actual operation, the control device 100 temporarily stores the received message M in the RAM 103 shown in FIG. Since the determination operation in S8 is being performed, the message M is read from the RAM 103 and sent to the device with the code number via the data bus 105. Of course, at this time, the data bus 105 and the code number are The output circuit between the device and the device corresponding to the code k has already been opened in step S6 described above, but in a different embodiment of the present invention, the partial step of opening the output circuit of the device corresponding to the code k in step S6 is It is also possible to insert the output circuit between step S8 and step S9 so that the output circuit is opened before step S9 and closed after step S9 every time it is necessary to transfer the message M. The device receives this message M, executes the job specified by the command from the device with code i, and sends a reply message MB as previously explained in FIG. 7(b) to an execution completion message el or It is sent to the control device W100 as e2. The control device 100 also receives this reply message MB as a message M in step SL, and the same goes for step 33.
S4. After passing through S8, in step S9, the reply message MB is sent to the code i which is the original sender! Transfer to location a. In this way, the command messages Ml and M2 from the device with code i are sequentially sent to the device with code i through the intermediary of the control device 100, and each time the job specified by the command is executed, Before the second command message M2 is issued after the command message M2 is executed, the first
As shown in the figure, if the message MS for starting an exchange with the device of code j is sent to the control device fi 100 from the device of code j, the determination result in step S3 within the control device 100 is negative. The flow moves to step S10 shown in the lower left, where the control device 100 sends a prohibition message P.
RH is sent to the source device with code j to inform that command exchange is not permitted. After a predetermined command exchange between the devices with code i and execution of a job based on the command is completed, the device with code i, which is the original sender, sends an exchange end message ■ to the control device 100, for example. The control device 100 also receives this message as message M in step Sl, and sends it in step S2.
S3. After passing through S4, the determination result in step S8 is positive, so the next flow moves to the lower right column starting at step 311. In the step 511, the flag value of the flag Fk corresponding to the code k is returned to zero, and in the following step 512, the flag value is sent to the next step. Of course, this cancellation message OFF may also be sent to the device in the code. Furthermore, in step S13, the output circuits corresponding to codes t and k are closed, thereby completing all command exchange operations between codes i and i. The above concludes the explanation of the operation of the command AC control according to the method of the present invention, but as is easily understood, the method of the present invention can be implemented in various ways within the scope of the invention in addition to the embodiments described above. For example, the manner in which the storage means of the control device stores devices in command exchange by code is not limited to the above-mentioned example, and various modified aspects may be adopted. In addition, Mr. M who controls the input/output circuit can, for example, insert the control step at an appropriate place in the flow, and can not only control the opening and closing of the output circuit but also control the input circuit in synchronization with this. Also, the combinations in which commands can be exchanged at the same time are not limited to one set as in the description of the embodiment, and it is possible to add or change hardware and software as appropriate to enable multiple sets to be exchanged at the same time. As mentioned above.

【Effect of the invention】

As explained above, according to the present invention, each electronic device is used as a dedicated device for exclusively controlling command exchange between devices in a system including a plurality of data processing devices and shared peripheral devices. In addition to assigning different codes to each electronic device, a command AC control device is installed that centrally accepts the command transmission path from each electronic device, and is equipped with a storage means for storing commands in the code of the electronic devices in communication. are exchanged via this control device, and in this case, the command source electronic device sends an AC start message and an AC end message containing the code of the command destination electronic device before and after the command exchange starts and ends, respectively. The command AC control device sends the command to the AC control device, and upon receiving the AC start message, the command AC control device allows the command exchange only when the code-specific storage contents in the storage means indicate that AC is not in progress. At the same time, the memory contents are rewritten during AC, and only when the AC end message is received, the memory contents are rewritten during non-AC, so that all the exclusive control functions that were conventionally handled by the peripheral device are now controlled. All commands that are handled by the device and cannot be exchanged are processed by the control device, eliminating confusion such as the transmission of useless messages to peripheral devices as in the past, making command exchange efficient and prompt. A controllable method is obtained. In addition, since the AC start and end messages are also processed within the control device, the burden placed on conventional peripheral devices is completely removed and the cost thereof can be reduced. On the other hand, what about the system in this method? On the Il device side, command exchange messages can be input and output via the input/output circuit regardless of whether the other party is a data processing device or a peripheral device, and the messages themselves need only be in a unified format. Build a comprehensive POS system by arbitrarily combining general-purpose data processing equipment and peripheral devices.
When configuring a system, you do not need to introduce a full-scale computer system; you can simply link a general-purpose ECR and peripheral devices via this control circuit, and you can add devices as needed. Since all you have to do is go, you can get great convenience with just the cost of adding a control device.

[Brief explanation of the drawing]

All the figures show the content of the present invention. Figure 1 is a functional diagram of a basic configuration example of the command AC control method according to the present invention, and Figure 2 shows a data processing device centered on the control device 100 and peripheral devices. 3 is a schematic diagram illustrating a pattern of command exchange between a data processing device and an attached peripheral device, and FIG. 4 is a pattern of command exchange between data processing devices via a control device. FIG. 5 is a schematic diagram illustrating the connection between an ECR as a data processing device and a printer, a floppy device, and a tape cassette device as peripheral devices, centering on the control device 100, and FIG. 7 is a message configuration diagram showing an example of the form of messages exchanged between devices during command exchange, and FIG. 8 shows the operational flow of the present invention method, centering on the control device. In figure 0, which is a flowchart, 100: command AC control device (or simply control device), 101: CPU, 102: ROM, 1
03: RAM including storage means F, 110: Control bag W11
Input/output circuit to 00, 120: Glue septacle for connecting electronic devices to the control device, E, EO, El,): i
, Ej: Data processing device or ECR, EC: AC end command, e, el, e2: Execution end message, F: Storage means, Fl, Fl, Fk, Fl: Flag, i, j: Data sent to the processing device. Sold code, k, l: Code assigned to peripheral device, Jl, J2: Job, M: Message, MD: Destination code part in message, Old: Source code part in message, MC: Command part in message, MP: data part in message, jB: reply message, Ml exchange start message, ME=exchange end message, Ml, M2. C.M.I. C? 12: Command message, OFF: Communication permission cancellation message, PRH: Communication prohibition message, RD
Y2 AC permission message, P, PO, P4. P5
．． P6. Pk. Pl: Peripheral device, SC: AC start command, WO, Ml
, W2°W3. Wi, Wj, Wk, Ml: connection cables. ``+1'--'''' 1.-)
,lFigure 1Figure 2Figure 3Figure 6Figure 7Country

Claims (1)

[Claims] 1) A method for exclusively controlling the exchange of commands between electronic devices in a multiple electronic device system including multiple data processing devices and peripheral devices commonly provided for them. The command AC control includes a storage means for allocating a different code to each of the electronic devices and storing the codes of electronic devices that are currently receiving commands, and centrally accepts command transmission paths from each electronic device. A device is provided, and the command source electronic device sends an exchange start message and an exchange end message including a code of the command destination electronic device to the command AC control device before and after the command exchange starts and ends, respectively, and the command AC control device Upon receiving the communication start message, the side allows the command exchange only when the code-specific memory content in the storage means indicates that the communication is not in progress, and rewrites the memory content during the communication. 1. A command exchange control method in a plurality of electronic device systems, characterized in that the stored contents are rewritten during non-interchange only when an exchange termination message is received. 2) A command exchange control method within a system of multiple electronic devices, characterized in that the data processing device is an electronic cash register (hereinafter referred to as ECR) in the method described in claim 1. 3) A command AC control method in a multiple electronic device system according to claim 1, wherein the peripheral device is an external storage device. 4) A command AC control method in a multiple electronic device system according to claim 1, wherein the peripheral device is a printing device. 5) A command AC control method within a multiple electronic device system, characterized in that the peripheral device is a data reading device in the method described in claim 1. 6) A command exchange control method within a plurality of electronic device systems according to claim 1, characterized in that a command and data for executing the command are sent as messages during command exchange. 7) A command exchange control method within a multiple electronic device system according to claim 1, characterized in that a command and a program transferred by the command are sent as messages during command exchange. 8) In the method described in claim 1, command exchange is performed exclusively from the data processing device to the peripheral device, and the peripheral device sends an execution completion message to the data processing device after executing the command. A command exchange control method within a system of multiple electronic devices, characterized in that a command is sent to the system. 9) A command exchange control method within a plurality of electronic device systems according to the method described in claim 1, characterized in that command exchange is performed between data processing devices. 10) In the method described in claim 1, the plurality of data processing devices include an ECR as a master device and an ECR as a slave device each equipped with an external storage device, and the command exchange is performed as a command source. A command exchange control method within a system of multiple electronic devices, characterized in that data or programs in the external storage device are transferred from the parent device ECR to the child device ECR based on a request from the child device ECR. . 11) In the method described in claim 1, the storage means in the AC control device is a storage area provided for each code assigned to each electronic device, and when a command is exchanged, the destination electronic device of the command is stored. A command exchange control method in a multiple electronic device system, characterized in that a code of a command source electronic device is written as a flag value indicating that command exchange is in progress in a flag area corresponding to the code. 12) A multiple electronic device system according to claim 1, characterized in that the exchange start message and the exchange end message issued from the command source electronic device include the code of the source electronic device. Command AC control method within.