JPH10161894A - Method for starting time specification program in distributed system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately start a time specification program in a distributed system which consists of a server and clients which are collectively controlled by the server. SOLUTION: An area where stores start data D21 which consists of a program name NA, a start time ST and a processed flag CF is provided in a data storing part 31 of a client CL1 or a server. When the server and the client CLA1 mutually start a program of time specification which is owned by the other party, the program name and start time of this program is sent as start data D21 before more than a prescribed time, and the server and the client CL1 separately refer to the received start data D21 and start the time specification program at a designated time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting a time designation program in a distributed system comprising a server as a main control device and one or more subordinate control devices controlled by the server. About.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing an example of a distributed system composed of a server and clients that are integrally controlled by the server. In the figure, SY is a system, SV is a server, CL1, CL2, and CL3 are each one client. The server SV and the clients CL1, CL2, and CL3 are signal lines SL.
Communicate with each other via, and operate unified as the system SY.

FIG. 6 is a block diagram showing the inside of the client CL1 shown in FIG. As shown, the client CL1 is connected to the control operation unit 1, the program storage unit 2, the data storage unit 3, the clock circuit unit 4, the input device 5, the display device 6, and the signal line SL (see FIG. 5) to communicate with the outside. And an input / output circuit 7 for inputting and outputting signals to be transmitted. The function of the client CL1 is realized when the control arithmetic unit of the control arithmetic unit 1 executes a program stored in the program storage unit 2. In the following description, a function realized by the control operation unit 1 executing the program will be described as being realized by the program. The basic program P is stored in the program storage unit 2.
0, a sequence control program P1 is stored, and programs other than these programs are also stored. However, other programs are not related to the present invention and are not shown. The basic program P0 is used by the client CL1 to process operation input from the input device 5, control the input / output circuit 7, control data display on the display device 6, and support other programs including the sequence control program P1. This is a program that performs basic operations. The sequence control program P1 is a program for controlling a group of programs that are executed at a specified time, among programs that provide services outside the system SY (see FIG. 5) by the client CL1. The programs controlled by the sequence control program P1 include programs stored in the program storage unit 2 and servers SV.
And a program started by a request controlled by the sequence control program P1. The data storage unit 3
It is a storage unit including a RAM, and stores data passing through the input / output circuit unit 7, the input device 5, display data to the display device 6, data referred to by the control operation unit 1, and the like. A start time area D1 for storing a start time is secured in the data storage unit 3, and the start time of each program to be started at a predetermined time when the system SY is started is set in this area by the sequence control program P1. Is done. The clock circuit unit 4 is a circuit that outputs pulses at fixed time intervals to notify the control arithmetic unit 1 of the lapse of accurate time or outputs a signal at a preset time.

[0005] The other clients CL2 and CL3 shown in FIG. 5 have the same configuration as the client CL1, and the server SV also includes the functions of the client CL1.
2, Individual description of the configuration of CL3 and the server SV is omitted. FIG. 7 shows a system SY1 as an example of application of the system SY shown in FIG. System SY1 is the client
CL1, CL2, CL3 and a server not shown. CL1, CL shown
2 and CL3 are the same clients as those shown in FIG. Client CL1 has parts PA1 and PA2
, And controls the assembling device that produces the partial assembly AA. That is, the client CL1 produces a component assembly AA from the components PA1 and PA2 via the assembly device. Similarly, the client CL2 produces a component assembly AB from the components PB1 and PB2, and the client CL3 produces a component assembly AC from the components PC1 and PC2. In the figure, M is a body, the body M is sequentially conveyed by a conveying device TR, and the body M is transferred to a station STA where a part assembly AA is sent out.
Station where AA is incorporated and part assembly AB is sent out
In the station STC where the component assembly AB is incorporated in the STB and the component assembly AC is sent out, the component assembly AC is incorporated and the process proceeds to the next step.

FIG. 8 is a process diagram showing a process of assembling a predetermined component assembly AB to the body M as shown in FIG. In the figure, the horizontal axis indicates the passage of time, and the vertical axis indicates the distance over which the body is transported. In the figure, M1 is the transfer device at time t1.
The body of the same format as the body M shown in FIG. 7 transmitted to the TR, and ACL1, ACL2, and ACL3 are each a client.
Represents the steps of the assembly work controlled by CL1, CL2, CL3.
Processes ACL1, ACL2, ACL3 start at time ta1, tb1, tc1, respectively, and the body M1 is connected to the station STA,
It ends at the time when it reaches STB, STC (see FIG. 7).

In FIG. 8, M2 is a body of the same type as the body M shown in FIG. 7, which is sent to the transport device TR following the body M1. As shown, the body M2 is the station ST of the client CL1 where the preceding body M1 is.
1 and is sent to the transport device TR at time t2 which coincides with time t11 when the process ACL1 of the client CL1 ends. Clients CL1, CL2, and CL3 are processes ACL1, ACL2, and AC, respectively.
L3 is started at times ta2, tb2, tc2 and ends at the time when the body M2 reaches the stations STA, STB, STC of the respective clients. That is, each process ACL1, ACL2, ACL3 is the next body M (j + 1) while the body Mj (j is the number of the body M) is moving between the stations of each process.
Parts are assembled in each of the steps.

The control of the process ACLi (i is the number of the process ACL) is performed by a sequence control program P1 (see FIG. 6) of the client CLi (i is the number of the client). Further, the programs controlled by the sequence control program P1 include a time designation program whose activation time is determined in advance and an immediate activation program which is activated immediately when an activation command signal is received. Further, even in the case of a time designation program, the designated time may be changed for convenience of the process.

[0008] As is apparent from the above description and illustration, the body Mi continuously delivered to the transport device TR is provided.
In order to correctly assemble the parts at each of the stations STA, STB and STC, the time interval for sending out the body Mi should be longer than the longest time of the process ACLi, and the process ACLi of each client CLi should be After the processing to M (i-1) is completed, it is necessary to start the processing to the body Mi before the body Mi reaches each station. Also, in order to increase the productivity of this system, the time interval for sending out the body Mi needs to be shortened as much as possible, so that a more accurate start time is required.

Since the time t1 at which the first body M1 shown in FIG. 8 is transmitted is a reference time for the subsequent steps to be continuously performed, the time t1 is calculated using the time calculated from the absolute time. It is convenient to use as a reference time. Therefore, this time t1 is sent from the server to each client CLi.
Each client CLi determines the start time of the program relating to its own process based on the transmitted time t1. In the case of updating the process, the reference time is set again.

[0010]

As described above, in a distributed system consisting of a server and one or more clients controlled by the server in a unified manner, a server or a server can be used in accordance with the requirements of the system to which this system is applied. It is necessary to start a time specification program held by each client at a time that satisfies a predetermined accuracy. On the other hand, in the operation of the system, there is a case where the reference time is transmitted from the server to reset the reference time of the client, or a program which is started immediately during the process is started. However, when the reference time needs to be changed without suspending the process, and when the reference time is transmitted from the server and the reference time of the client is reset, the state at the time of reception by each client is different. During a period from a client whose reference time is updated first to a client whose reference time is updated last, there is a time zone in which each client has a different reference time. Also, when starting an immediate start program in the middle of the process,
Since there is a time delay until the activation signal is received by the client, a delay of more than an allowable value may occur depending on the state of the signal line.

[0011] In view of the circumstances described above, the present invention provides a distributed system consisting of a server and one or more clients that are integrally controlled by the server. It is another object of the present invention to provide a method for accurately starting a processing target.

[0012]

According to the present invention, there is provided, in accordance with the present invention, a server which is a main control unit and one or more subordinate control units which are integrally controlled by the server. In a distributed system composed of clients, the storage means of each client constituting the system includes:
A boot data area is provided which stores boot data including a program name of a time specifying program which is a program to be started at a specified boot time and a boot time of the program. The start data of the individual time designation program held by the client is transmitted at least a predetermined time before the start time included in the start data, and each client stores the received start data in the start data area,
Each client refers to the contents of the activation data area, and sequentially executes the time designation program that has reached the activation time.

Therefore, in the client, the start time of the time designation program is stored in the storage means before the time reaches this time, and the time designation program is started with reference to the stored start time. Further, according to the invention of claim 2, in a distributed system comprising a server which is a main control device and one or more clients which are integrally controlled by the server, a server constituting the system In the storage means, there is provided a boot data area, which is an area for storing boot data including a program name of a time specifying program that is a program to be started at a specified boot time and a boot time of the program, and the client The server transmits the start data of the held time designation program at least a predetermined time before the start time included in the start data, the server stores the received start data in the start data area, and the server stores the contents of the start data area. With reference to the above, the time designation programs reaching the start time are sequentially executed.

Therefore, in the server, the activation time of the time designation program is stored in the storage means before the time reaches this time, and the time designation program is activated with reference to the stored activation time. Further, claim 1 or claim 2
In the invention of the above, a processing completion flag which is a flag indicating whether or not the program indicated by the program name has been executed is added to the start-up data for each time designation program name, and the client or the server performs Set the processed flags of all time specification programs related to this series of processing to the value indicating unprocessed, and process the processing completed flag of this program every time the processing of one time specification program in the series of processing is completed It is preferable that the client or the server next activates the time designation program that is closest to the current time among the time designation programs whose processed flag has the value representing the unprocessed state. That is, when the client or the server determines the time designation program to be started based on the current time, for the time designation program in which the processed flag has a value indicating that the processing has been completed, the start time of this program is set to the current time. The process of comparing with the time of (1) can be omitted.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a block diagram showing the inside of a client CLA1 constituting a distributed system SY2, which is an example of an embodiment of the present invention. Distributed system
SY2 is a server in the distributed system SY shown in FIG.
This is a system in which a server SV1 is connected instead of the SV, and a plurality of clients CLAi (i is the number of the client CLA) having the same configuration as the client CLA1 are connected instead of the clients CL1, CL2, and CL3. Omitted.

As shown in the figure, the client CLA1 comprises a control operation unit 1, a program storage unit 21, a data storage unit 31, a clock circuit unit 4, an input device 5, a display device 6, and an input / output circuit 7. Among the components, FIG.
The components having the same reference numerals as those of the client CL1 shown in (1) have the same functions as the components of the client CL1 and will not be described.

The program storage unit 21 includes the program storage unit 2 shown in FIG. 6 and the sequence control program P1 shown in FIG.
This is a program storage unit having the same function as the program storage unit 2 except that it stores an order control program P11 instead of.
The sequence control program P11 is different from the sequence control program P1 in the method of activating the time designation program, and implements the following features of the present invention.

The data storage unit 31 constitutes a part of the storage unit of the client CLA1, and has the same function as the data storage unit 3 shown in FIG. A start data area D21 for storing start data D21 including a program name NA of the program, a start time ST of the program, and a processed flag CF is secured. The data and the area for storing the data are denoted by the same reference numerals.

FIG. 1B shows details of the start data D21 of the client CLA1 shown in FIG. 1A. As shown in the drawing, the start data D21 includes a program name NA representing a time designation program, a start time ST which is a time at which a program represented by the program name should be activated, and a program represented by the program name has been executed. The start data area D21 includes a program name area NA, a start time area ST, and a processed flag area CF. The start time ST is defined as a start time of a group of processes including one or more time specification programs as a reference start time, in order to clearly show the relationship between the start times between the time specification programs, and starting from this time. Set. The processed flag CF defines 0 as before processing and 1 as processed. For example, in the example shown in the figure, the program represented by the program name TP1 which is one of the time designation program names NA is a program to be started one minute after the reference start time, and the processed flag CF of this program is The program represented by the program name TP2 which is one of the values indicating the later and which is another one of the time designation program names NA is a program to be started three minutes after the reference start time, and the processing of this program The completed flag CF has a value of 0 indicating before processing.

Since the server SV1 includes the function of the client CL1 with respect to the time designation program related to the present invention, the description of the server SV1 is omitted. Figure 2 (a) shows the servers in the distributed system SY2.
The flowchart showing the operation related to the activation of the time designation program of the SV1 will be described, and the operation of the server SV1 will be described.
The server SV1 executes the processing shown in FIG. 2A at the time of starting a group of processing by the distributed system SY2 or when it becomes necessary to individually start a time designation program. In the process FS1, the server SV1 determines whether or not a value obtained by subtracting a predetermined time from the activation time of the time designation program to be executed by the client is later than the current time. The predetermined time is
In the next process FS2, the server SV1 sends the program name of the time designation program to be executed and the start time, and correctly executes the time designation program longer than the time until the transmitted data is reliably received by the client. This is enough time to start up. If the time obtained by subtracting the predetermined time from the start time in the process FS1 is later than the current time in the process FS1, the server SV1 executes the process FS2, and in this process, executes the program name and the start time of the program represented by the program name. Is transmitted to the target client as startup data. Therefore, the client can always receive the start time of the time designation program to be started before the start time of this program, and prepare for execution.

FIG. 2 (b) shows the server SV shown in FIG. 2 (a).
Client CLA1 (Fig. 1)
(A) of FIG. 3) is shown.
As shown, when the client CLA1 receives the time designation program name and the start time of this program, the client
In step 1, the current time is compared with the received start time,
If the start time is after the current time, the process proceeds to process FC2, where the received program name and the start time are stored in the start data area.
D21 (see (a) of FIG. 1), and then, in process FC3, the processed flag is set to an unprocessed value. If the client CLA1 determines in the process FC1 that the activation time has passed the current time, the process proceeds to the process FC4 and transmits a message indicating that the activation is not possible to the server SV1.

FIG. 3 is a flowchart showing the processing of the time designation program in the client CL1. The client CL1 executes the processing shown in the figure at a constant cycle necessary to satisfy the predetermined accuracy of the time designation program. First, in the process FC11, it is determined whether or not the processed flag of one time designation program is a processed value by referring to the start data D21 (see FIG. 1). If the value is already processed
Proceeding to FC12, it is determined whether or not the start time of this program has reached a predetermined range at the current time. If it has reached the predetermined range, the process proceeds to process FC13 to start the corresponding program. In the process FC14, the process FC11
If there is a program for which the following processing has not been processed, the processing from step FC11 on is executed for this program. If the value of the processed flag has been processed in process FC11, and if the process FC
If it is determined in 12 that the time at which the corresponding program should be started has not arrived, only the determination of the process FC14 is performed. Note that if the start-up data in the start-up data area D21 is arranged in the order of the start-up time, the start-up order of the time designation program is in the order of the arrangement, so that the processing shown in FIG. 3 can be simplified.

FIG. 4 shows that the client CL1 sends the server SV1.
9 shows a flowchart showing a process when requesting activation of a time designation program. Fig. 4 (a) shows the client
FIG. 4B shows the process in the server SV1, and FIG. 4B shows the process in the server SV1. When the client CL1 requests the server SV1 to start a program held by the server SV1, the client CL1 treats this program as a time designation program, and
First, the process FC21 is executed. That is, in this process, the client CL1 confirms that the time obtained by subtracting a predetermined time from the start time of the requested program is after the current time, and if this condition is satisfied, the client CL1 determines the program to be started in process FC22. Send the program name and start time.

The server SV1 that has received the program name and the start time transmitted by the processing of FIG.
Execute the process shown in (b). That is, first, the process FS21 is executed, and if the start time is after the current time, the process proceeds to the process FS22,
The received program name and start time are stored in the start data area of the server SV1, and the process proceeds to step FS23 to set the processed flag to an unprocessed value. In the process FS21, if the requested activation time has passed the current time, the process proceeds to the process FS24, where a message indicating that the activation is impossible is transmitted to the client CL1. The server SV1 executes the time designation program with reference to the activation data stored in the activation data area by the same mechanism as the processing of the time designation program of the client CL1 shown in FIG.

It should be noted that the above-mentioned time designation program can be treated as a time designation program by designating the activation time of this program as well as a program whose activation time is determined in advance.

[0026]

As described above, according to the method of the first aspect of the present invention, a server which is a main control device and one or more client devices which are one or more subordinate control devices which are controlled integrally by the server. In a distributed system consisting of
In a storage means of each client constituting the system, a start data area which is an area for storing start data including a program name of a time designation program which is a program to be started at a specified start time and a start time of this program is stored. Provide. Then, the server transmits, to each of the clients, the activation data of the individual time specification program held by each client at least a predetermined time before the activation time included in the activation data, and each client transmits the received activation program. The data is stored in the activation data area, and each client sequentially executes the time designation program that has reached the activation time by referring to the contents of the activation data area.

Therefore, each client constituting the distributed system can start its own time designation program at the correct time. In addition, since a general program whose start time is not scheduled is not prevented from adding a start time and giving a start request, a general program can also be started at a correct start time.

According to a second aspect of the present invention, there is provided a distributed system comprising a server which is a main control device, and one or more clients which are controllable by the server. A program name of a time designation program which is a program to be activated at a designated activation time, in a storage means of a server constituting the system,
An activation data area, which is an area for storing activation data including the activation time of the program, is provided. Then, the client transmits the start data of the time designation program held by the server at least a predetermined time before the start time included in the start data, the server stores the received start data in the start data area, and the server With reference to the contents of the activation data area, the time designation programs that have reached the activation time are sequentially executed.

Therefore, the server constituting the distributed system can start the time designation program held by the server at a correct time in response to a request from the client. In addition, since a general program whose start time is not scheduled is not prevented from adding a start time and giving a start request, a general program can also be started at a correct start time.

Further, according to the method of the third aspect of the present invention,
For each time-specified program name, a processing completion flag, which is a flag indicating whether or not the program indicated by the program name has been executed, is added to the start-up data, and the client or server starts this series of processing at the beginning of the series of processing. Set the processed flags of all the time specification programs related to the process to the value indicating unprocessed, and set the processed flag of this program to the value indicating processed each time the processing of one time specification program in the series of processing is completed change. Then, the client or server next activates the time designation program closest to the current time among the time designation programs whose processed flag has a value indicating unprocessed.

Therefore, the client or server can specify the next time specification program to be processed next simply by comparing the current time with the specified time of the time specification program whose processed flag has not been processed. A time designation program can be processed.

[Brief description of the drawings]

[0032]

FIG. 1 is a block diagram showing a configuration of a client constituting a distributed system to which a method according to the present invention is applied, which is an example of an embodiment of the present invention;

[0033]

2 is a flowchart showing processing in a server and a client of the system including the client shown in FIG. 1;

[0034]

FIG. 3 is a flowchart showing a process of referring to startup data in the client shown in FIG. 1;

[0035]

FIG. 4 is a flowchart showing processing in a server and a client in a system to which the method of the present invention is applied;

[0036]

FIG. 5 is a block diagram of an example of a distributed system.

[0037]

6 is a block diagram showing a configuration of a client of the distributed system shown in FIG.

[0038]

FIG. 7 is a block diagram of a specific example of a distributed system.

[0039]

FIG. 8 is an explanatory diagram of the operation of the distributed system shown in FIG. 7;

[0040]

[Explanation of symbols]

 CLA1 Client 1 Control operation unit 21 Program storage unit P0 Basic program P11 Sequence control program 31 Data storage unit D21 Start-up data area NA Program name area ST Start-up time area CF Processed flag area 4 Timing circuit unit 5 Input device 6 Display device 7 Input Output circuit

Claims (3)

[Claims] In a distributed system comprising a server which is a main controller and one or more clients which are subordinately controlled by the server, the storage means of each client constituting the system includes: A start data area is provided which is an area for storing start data including a program name of a time designation program which is a program to be started at a specified start time and a start time of the program.
The start data of each time specification program held by each client is transmitted at least a predetermined time before the start time included in the start data, and each client stores the received start data in the start data area, A method of activating a time designation program in a distributed system, wherein the client refers to the contents of the activation data area and sequentially executes the time designation program that has reached the activation time. 2. In a distributed system comprising a server which is a main control device and one or more clients which are integrally controlled by the server, a storage means of a server constituting the system is designated by A start data area, which is an area for storing start data including a program name of a time designation program which is a program to be started at the set start time and a start time of the program, is provided. The start data is transmitted at least a predetermined time before the start time included in the start data, the server stores the received start data in the start data area, and the server refers to the contents of the start data area to execute the start time. Time specification program in a distributed system, characterized by sequentially executing time specification programs that have arrived at How to start the ram. 3. The method for starting a time designation program of a distributed system according to claim 1 or 2, wherein, for each time designation program name, the start data indicates whether the program indicated by the program name has been executed. At the beginning of a series of processes, the client or server sets the processed flags of all the time specification programs related to the series of processes to a value representing unprocessed, and sets the Each time the processing of one time specification program is completed, the processed flag of this program is changed to a value indicating that processing has been completed. A method for starting a time designation program in a distributed system, wherein the time designation program closest to the time is started next.