JPH11261577A - Device and method for transferring data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add a time stamp to external data and to enable a master device to execute fault analysis or the like. SOLUTION: A memory managing part 19 is provided for transmitting the external data time sequentially preserved by an external data recording part 20 when a polling request is issued from a data transfer part 14 of a master device 11 and based on the time of data transfer recorded by a time stamp recording part 15, the time stamp is added to the respective external data transmitted from the memory managing part 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer device and a data transfer method in which a master device broadcasts data to a plurality of remote devices and the master device polls and receives data from the plurality of remote devices. .

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a conventional data transfer device. In FIG. 9, reference numeral 1 denotes a device which broadcast-transfers data (hereinafter referred to as "internal data") to remote devices 2 and 3, and , 3 which issue a polling request when receiving data (hereinafter referred to as “external data”), 2 and 3 receive internal data broadcast-transferred from master device 1 and poll from master device 1. Upon receiving the request,
A remote device 4 that transmits periodically sampled external data to the master device 1 is a network connecting the master device 1 and the remote devices 2 and 3.

Next, the operation will be described. First, when the power of the master device 1 is turned on, the master device 1 is initialized. When a predetermined transmission cycle is reached, the master device 1 broadcast-transfers the internal data to the remote devices 2 and 3 (see FIG. 10). . Thereby, the remote devices 2 and 3
Receives the internal data broadcast-transferred from the master device 1.

When the remote devices 2 and 3 receive the internal data from the master device 1, the remote devices 2 and 3 output the internal data to the outside and perform predetermined digital processing and the like based on the internal data. Also, the remote device 2,
When the internal data is received from the master device 1, the external data is periodically sampled by, for example, a water level meter or the like, and stored in the memory.

On the other hand, when the broadcast transfer of the internal data is completed, the master device 1 issues a polling request to each of the remote devices 2 and 3 in order to receive the external data sampled by the remote devices 2 and 3. I do. The remote devices 2 and 3 are connected to the master device 1
When a polling request is received from the remote device 2, the external data stored in the memory is transmitted to the master device 1 (FIG. 11 shows a case where external data is received from the remote device 2). As a result, the master device 1 communicates with the remote devices 2
3 can receive the sampled external data.

Here, if it is necessary to confirm whether or not the internal data broadcast-transferred from the master device 1 has been correctly output from the remote device 2, as shown in FIG. When performing the broadcast transfer, the internal data is stored in the memory 1b. When the remote device 2 receives the internal data, the data output unit 2b of the remote device 2 stores the internal data in the memory 2a when outputting the internal data to the outside.

[0007] The remote device 2 is connected to the master device 1.
When the external data is transmitted to the master device 1, the internal data stored in the memory 2a is transmitted to the master device 1 together with the external device. When the internal data is returned from the remote device 2, the comparing unit 1a of the master device 1 compares the internal data with the internal data stored in the memory 1b. It is determined that the data has been output, and if they do not match, it is determined that the internal data has not been correctly output.

The master device 1 is connected to the remote devices 2 and 3
If the remote devices 2 and 3 are capable of adding a time stamp to the external data, for example, when analyzing the external data transmitted from the server and performing, for example, a failure analysis of the system, it is effective in performing the failure analysis, etc. Is clear, but in a system that requires high-speed response of internal data and external data, the transmission cycle of broadcast transfer and the transmission cycle of external data accompanying polling requests are extremely short,
There is a great need to reduce the amount of data, and it has been difficult to add a time stamp to external data.

[0009]

Since the conventional data transfer device is configured as described above, data can be transmitted and received between the master device 1 and the remote devices 2 and 3; When high-speed response is required, the time stamp cannot be added to the external data due to the necessity of reducing the data amount, and the master device 1 sufficiently analyzes the failure of the system based on the external data. There was a problem that can not be.

Further, the comparison unit 1a of the master device 1 compares the internal data returned from the remote device 2 with the internal data stored in the memory 1b, so that the internal data broadcast-transferred from the master device 1 can be accurately determined. (Hereinafter referred to as "confirmation process"), the internal data returned from the remote device 2 is temporarily stored in the memory 2a of the remote device 2. Data, which is not actually output from the data output unit 2b of the remote device 2, it is not possible to perform the confirmation process with high accuracy, and the processing capability of the remote device 2 is low, If the internal data output processing is not completed within the external data transmission cycle time accompanying the request, the internal data is Since that can not be sent back to the,
There is also a problem that the comparison unit 1a of the master device 1 cannot execute a process of confirming the internal data.

The processing capability of the remote device 2 is low,
In order to solve the problem that the internal device cannot return internal data within the transmission period of the external data associated with the polling request and the master device 1 cannot execute the confirmation processing, the remote device 2 receives the polling request for a certain period of time after receiving the polling request. Even if internal data cannot be returned to the
Japanese Patent Application Laid-Open No. 4-364628 discloses a technique for enabling the master device 1 to receive internal data and the like returned from the Internet. However, since each remote device needs to add a time stamp to the internal data, It is necessary to synchronize between the timers mounted on each remote device,
Since internal data and the like are randomly returned from each remote device, the master device 1 needs to prepare a table or the like for managing a polling state, and there has been a problem that the device configuration becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a data transfer apparatus and a data transfer method capable of adding a time stamp to external data without deteriorating high-speed data responsiveness. The purpose is to obtain. Another object of the present invention is to provide a data transfer device and a data transfer method capable of accurately confirming whether or not internal data broadcast-transferred from a master device has been accurately output from a remote device. . Still another object of the present invention is to provide a data transfer device and a data transfer method capable of reliably receiving internal data and the like returned from a remote device having a low processing capability without complicating the configuration of a master device.

[0013]

The data transfer device according to the present invention includes a data transmission means for transmitting external data stored in chronological order by the data storage means when a polling request is issued from the data request means. , A time stamp is added to each external data transmitted from the data transmitting means.

In the data transfer apparatus according to the present invention, when a polling request is issued from the data request means, the data transfer means for transmitting the external data stored in time series by the data storage means is provided, and the data transfer means records the data. A time stamp is added to each external data transmitted from the data transmitting means based on the time at which the data was transferred.

The data transfer device according to the present invention is such that the internal data externally output by the output means is input and the internal data is returned.

In the data transfer apparatus according to the present invention, the internal data transferred by the data transfer means is compared with the internal data externally output by the output means.

In the data transfer apparatus according to the present invention, when the comparison result of the comparison means indicates a data mismatch, the data transfer means retransmits the internal data.

In the data transfer apparatus according to the present invention, upon receiving a request for transmission of processing speed information from the information requesting means, the data transfer apparatus transmits the processing speed information of the remote device.

The data transfer device according to the present invention, when issuing a polling request to a remote device that cannot complete data processing within the polling request period, requires a remote device that does not actually exist beforehand. In this case, a dummy polling request is issued.

According to the data transfer method of the present invention, when a polling request is issued from a data requesting step, a data transmitting step of transmitting external data stored in time series by the data storing step is provided. A time stamp is added to each transmitted external data.

According to the data transfer method of the present invention, when a polling request is issued from a data request step, a data transmission step of transmitting external data stored in time series in the data storage step is provided. A time stamp is added to each external data transmitted from the data transmission step based on the recorded time at the time of data transfer.

According to the data transfer method of the present invention, the internal data output from the outside is input, the internal data is returned, and the internal data is compared with the internal data transferred in the data transfer step. It is.

According to the data transfer method of the present invention, when a polling request is issued to a remote device that cannot complete data processing within the polling request request cycle time, a remote device that does not actually exist in advance is In this case, a dummy polling request is issued.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a data transfer apparatus according to a first embodiment of the present invention. In FIG. A master device that issues a polling request when receiving data (hereinafter, referred to as “external data”);
Is one of a plurality of remote devices connected to the master device 11 via the network,
Is a remote device that, when receiving a polling request from the master device 11 while receiving internal data broadcast transferred from the master device 11, periodically transmits external data sampled to the master device 11.

Reference numeral 13 denotes a timer (data transfer means) of the master device 11, and 14 broadcast-transfers internal data of the master device 11, obtains a time at the time of data transfer from the timer 13, and time stamps the time. The data transfer unit (data transfer unit, data request unit) that issues a polling request when the data is recorded in the recording unit 15 and the broadcast transfer of the internal data is completed, and 15 is a time stamp record that records the time at the time of data transfer (Data transfer means).

Further, reference numeral 16 denotes a data receiving section (data receiving means) for receiving internal data broadcast-transferred from the data transfer section 14 of the master device 11, and 17 externally outputs the internal data received by the data receiving section 16. An external output section (output means), 18 is an external input section (data storage means) for periodically sampling external data, 1
9 records the external data sampled by the external input unit 18 in the external data recording unit 20 in order,
When a polling request is issued from the data transfer unit 14 of the master device 11, a memory management unit (data storage unit, data transmission unit) that transmits external data stored in time series by the external data recording unit 20, An external data recording unit (data storage unit) that stores data in a time series.

A data receiving unit 21 receives external data transmitted from the memory management unit 19 of the remote device 12 and records the external data in an external data recording unit 22. A data storage unit 22 stores time-series external data. The external data recording unit 23 performs the external data recording unit 22 based on the data transfer time stored by the time stamp recording unit 15.
A time stamp adding unit (time stamp means) for adding a time stamp to each external data recorded in the external data.
FIG. 2 is a flowchart showing a data transfer method according to the first embodiment of the present invention.

Next, the operation will be described. First, when the power of the master device 11 is turned on, the master device 11 is initialized (step ST1). When a predetermined transmission cycle is reached, the data transfer unit 14 of the master device 11 reads the time from the timer 13 and reads the time. To the time stamp recording unit 15
To record. After recording the time in the time stamp recording unit 15, the data transfer unit 14 broadcast-transmits the internal data to each remote device connected to the network (step ST2).

Thus, when receiving the internal data broadcast-transferred from the master device 11, the data receiving unit 16 of the remote device 12 outputs the internal data to the external output unit 17 and a data processing unit (not shown). , The external output unit 17 externally outputs the internal data. Also,
A data processing unit performs a predetermined digital processing or the like based on the internal data.

On the other hand, the external input unit 18 is
When the power supply 2 is turned on (step ST11), sampling processing of external data (for example, external data measured by a water level meter or the like) is started at a cycle of 1 ms (step ST12), and the external data is sampled. Each time, the external data is output to the memory management unit 19 (steps ST13 and ST14). Then, when the external data is output from the external input unit 18, the memory management unit 19 records the external data in the external data recording unit 20 in order, and stores each external data in time series (step ST
13).

The data transfer unit 1 of the master device 11
When the broadcast transfer of the internal data is completed, 4 issues a polling request to each remote device in order to receive the external data sampled by each remote device connected to the network (step ST3). When the memory management unit 19 of the remote device 12 receives the polling request from the data transfer unit 14 of the master device 11 (step ST15), the memory management unit 19 of the external device records the latest external data among the external data recorded in the external data recording unit 20. , And transmits the data to the master device 11 (step ST16).

The data receiving unit 2 of the master device 11
When the external data is sequentially transmitted from the remote device 12, the external device 1 receives the external data in order and records each external data in the external data recording unit 22 in time series. In this way, when each external data is stored in chronological order, the time stamp adding unit 23 adds a time stamp to each external data based on the data transfer time recorded by the time stamp recording unit 15. (Step ST4).

Specifically, when the sampling cycle of the external input unit 18 is 1 ms, the external data recording unit 22 stores 1
Since the external data having a period of ms is recorded, as shown in FIG.
Is added to the time (1.0 in the example of FIG. 3).
0) In the external data before one sampling, the time obtained by subtracting 0.01 from the time added to the latest external data (FIG. 3)
In the example, 0.59) is added. The external data before N samplings is given a time obtained by subtracting 0.01 × N from the time given to the latest external data.

As is apparent from the above, the first embodiment
According to the above, when a polling request is issued from the data transfer unit 14 of the master device 11, a memory management unit 19 for transmitting external data stored in time series by the external data recording unit 20 is provided, and the time stamp recording unit 15 Is configured to add a time stamp to each external data transmitted from the memory management unit 19 based on the time at the time of data transfer recorded according to the above. A stamp can be added, and as a result, there is an effect that a failure analysis or the like of the system can be sufficiently performed.

Embodiment 2 FIG. 4 is a configuration diagram showing a data transfer device according to a second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 24 denotes an input unit (input means) for inputting internal data externally output from the external output unit 17;
1 is a memory for storing the internal data input by the input unit 24, and 26 is a memory management for returning the internal data stored by the memory 25 to the master device 11 in addition to having the same function as the memory management unit 19 in FIG. Unit (data storage means, data transmission means, data return means), 27 is a memory for storing the internal data transferred by the data transfer unit 14, and 28 is the internal data stored by the memory 27 and returned from the memory management unit 26. A comparing unit (comparing means) for comparing the internal data.

Next, the operation will be described. The broadcast transfer of the internal data and the polling transmission of the external data are the same as those in the first embodiment, but it is necessary to confirm whether or not the internal data broadcast-transferred from the master device 11 is correctly output from the remote device 12. In some cases, when the data transfer unit 14 broadcast-transmits the internal data, the internal data is stored in the memory 27.

On the other hand, the input unit 24 receives the internal data externally output from the external output unit 17 and stores it in the memory 25. Therefore, when the memory management unit 26 receives the polling request from the master device 11, it receives the external data. The internal data is returned to the master device 11 together with the external data recorded in the data recording unit 20. Then, the comparison unit 2 of the master device 11
8, when the internal data is returned from the remote device 12, the internal data is compared with the internal data stored in the memory 27, and if they match, it is determined that the internal data has been correctly output. If they do not match, it is determined that the internal data has not been correctly output.

As is apparent from the above, this embodiment 2
According to the configuration, the internal data transferred by the data transfer unit 14 and the internal data externally output from the external output unit 17 are configured to be compared with each other, so that based on the internal data actually output from the external output unit 17, The confirmation processing can be performed, and as a result, an effect that the confirmation processing can be performed with high accuracy is achieved.

Embodiment 3 FIG. 5 is a configuration diagram showing a data transfer device according to a third embodiment of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 29 denotes a notification unit for notifying the data transfer unit 30 of the comparison result of the comparison unit 28. Reference numeral 30 has the same function as the data transfer unit 14 in FIG. Has a data transfer unit (data transfer means, data request means,
Retransmission means).

Next, the operation will be described. In the second embodiment, the comparison unit 28 of the master device 11 compares the internal data transferred by the data transfer unit 14 with the internal data returned by the remote device 12. If the comparison result indicates a data mismatch, the data transfer unit 30 may retransmit the internal data. As a result, if the internal data is not correctly output from the remote device 12,
The internal data can be transferred to the remote device 12, and as a result, there is an effect that the reliability of the system is improved.

Embodiment 4 FIG. FIG. 6 is a block diagram showing a data transfer device according to a fourth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 31 has the same function as the data transfer unit 14 of FIG. 4, and also requests transmission of processing speed information indicating whether the remote device 12 can complete data processing within the polling request request cycle time. When the remote device 12 is a remote device that cannot complete the data processing within the polling request period, when issuing the polling request,
A data transfer unit (data transfer unit, data request unit, information request unit, dummy unit) having a dummy function of issuing a dummy polling request to a remote device that does not actually exist in advance, and 32 is a memory management unit in FIG. In addition to having a function similar to that of the memory device 26, a memory management unit (data storage unit, data transmission unit, data return unit, Information responding means) and 33 are polling information management tables for storing processing speed information of each remote device connected to the network. FIG. 7 is a flowchart showing a data transfer method according to the fourth embodiment of the present invention.

Next, the operation will be described. The broadcast transfer of the internal data and the like are the same as those in the second embodiment. However, in the case of a system that requires high-speed data responsiveness, the request cycle of the polling request is short, so that the remote device having a low data processing capability is polled. The data processing cannot be completed within the requested cycle time of the request, and it cannot be connected to the network.

Therefore, in the fourth embodiment, the data transfer unit 31 performs the broadcast transfer of the internal data so that a remote device having a low data processing capability can be connected to the network as needed. Prior to this, all the remote devices connected to the network are requested to transmit processing speed information indicating whether data processing can be completed within the polling request period (step ST22).

Then, the memory management unit 3 of each remote device
When the processing speed information of the remote device is transmitted from 2, the data receiving unit 21 of the master device 11, as shown in FIG.
The processing speed information of each remote device is stored in the polling information management table 33 (steps ST23 and ST2).
4). Then, when issuing a polling request to each remote device, the data transfer unit 31 refers to the polling information management table 33 and cannot complete data processing within the polling request request period (see FIG. 8). In the example, the remote device of the address 1, 2, 3)
, A dummy polling request is issued to a remote device that does not actually exist, and then a polling request is issued (step ST25).

As a result, the request cycle of the polling request to the remote device having a low data processing capability becomes longer,
There is an effect that a remote device having a low data processing capability can be connected to a network as needed.

[0046]

As described above, according to the present invention, when a polling request is issued from a data requesting means, a data transmitting means for transmitting external data stored in chronological order by the data storing means is provided. Since the time stamp is added to each external data transmitted from the data transmitting means, the time stamp can be added to the external data without deteriorating the high-speed response of the data. Therefore, there is an effect that a failure analysis of the system can be sufficiently performed.

According to the present invention, when the polling request is issued from the data request means, the data transmission means for transmitting the external data stored in time series by the data storage means is provided, and the data recorded by the data transfer means is provided. Since the time stamp is added to each external data transmitted from the data transmission means based on the time at the time of transfer, it is possible to add the time stamp to the external data without deteriorating the high-speed response of the data. As a result, there is an effect that a failure analysis or the like of the system can be sufficiently performed.

According to the present invention, since the internal data externally output by the output means is input and the internal data is returned, it is determined whether or not the internal data has been correctly externally output from the output means. There is an effect that can be done.

According to the present invention, since the internal data transferred by the data transfer means and the internal data externally output by the output means are compared, the internal data broadcast-transmitted from the master device can be accurately remote-controlled. There is an effect that it is possible to accurately confirm whether or not output has been performed from the device.

According to the present invention, when the comparison result of the comparison means indicates a data mismatch, the data transfer means is configured to retransmit the internal data, so that the internal data is not accurately output from the remote device. In this case, the internal data can be transferred to the remote device again, and as a result, the reliability of the system is improved.

According to the present invention, when the transmission request of the processing speed information is received from the information requesting means, the processing speed information of the remote device is transmitted, so that the data processing capability of the remote device connected to the network is reduced. As a result, the polling request cycle can be changed.

According to the present invention, when a polling request is issued to a remote device that cannot complete data processing within the polling request period,
Since a dummy polling request is issued in advance to a remote device that does not actually exist, the request cycle of the polling request to a remote device having a low data processing capability becomes longer, and as a result, the remote device having a low data processing capability is generated. Also, there is an effect that it is possible to connect to a network as needed.

According to the present invention, when the polling request is issued from the data requesting step, a data transmitting step for transmitting the external data stored in chronological order by the data storing step is provided, and the data is transmitted from the data transmitting step. Since the time stamp is added to each external data, it is possible to add the time stamp to the external data without deteriorating the high-speed response of the data. There is an effect that can be sufficiently implemented.

According to the present invention, when a polling request is issued from the data requesting step, a data transmitting step of transmitting external data stored in chronological order by the data storing step is provided, and the data is recorded by the data transmitting step. Since the time stamp is added to each external data transmitted from the data transmission step based on the time at the time of data transfer, the time stamp can be added to the external data without deteriorating the high-speed response of the data. As a result, there is an effect that a failure analysis or the like of the system can be sufficiently performed.

According to the present invention, since the external data is input, the internal data is returned, and the internal data is compared with the internal data transferred in the data transfer step. There is an effect that it is possible to accurately confirm whether or not the internal data broadcast-transferred from the device is correctly output from the remote device.

According to the present invention, when a polling request is issued to a remote device that cannot complete data processing within the polling request cycle time,
Since a dummy polling request is issued in advance to a remote device that does not actually exist, the request cycle of the polling request to a remote device having a low data processing capability becomes longer, and as a result, the remote device having a low data processing capability is generated. Also, there is an effect that it is possible to connect to a network as needed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a data transfer device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a data transfer method according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a process of adding a time stamp.

FIG. 4 is a configuration diagram showing a data transfer device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a data transfer device according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram showing a data transfer device according to a fourth embodiment of the present invention.

FIG. 7 is a flowchart showing a data transfer method according to a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating the storage status of processing speed information of each remote device.

FIG. 9 is a configuration diagram showing a conventional data transfer device.

FIG. 10 is an explanatory diagram illustrating a broadcast transfer.

FIG. 11 is an explanatory diagram illustrating polling transmission.

FIG. 12 is an explanatory diagram illustrating return of internal data.

[Explanation of symbols]

13 timer (data transfer unit), 14 data transfer unit (data transfer unit, data request unit), 15 time stamp recording unit (data transfer unit), 16 data reception unit (data reception unit), 17 external output unit (output unit) ), 18 external input unit (data storage unit), 19 memory management unit (data storage unit, data transmission unit), 20
External data recording unit (data storage unit), 23 time stamp addition unit (time stamp unit), 24 input unit (input unit), 26 memory management unit (data storage unit,
Data transmission means, data return means), 28 comparison section (comparison means), 30 data transfer section (data transfer section, data request section, retransmission section), 31 data transfer section (data transfer section, data request section, information request section) , Dummy means), 32 memory management units (data storage means, data transmission means, data return means, information response means).

Claims (11)

[Claims] 1. A data request unit for issuing a polling request, a data storage unit for periodically sampling external data and storing the external data in a time series, and when a polling request is issued from the data request unit. A data transmission unit for transmitting external data stored in chronological order by the data storage unit; and a time stamp unit for adding a time stamp to each external data transmitted from the data transmission unit. 2. A data transfer means for performing a broadcast transfer of internal data and recording a time of the data transfer, a data request means for issuing a polling request when the data transfer means completes the broadcast transfer, Data receiving means for receiving internal data broadcast-transferred from the means, data storing means for periodically sampling external data and storing the external data in time series, and a polling request issued from the data requesting means Data transmission means for transmitting external data stored in chronological order by the data storage means, and each external data transmitted from the data transmission means based on the time of data transfer recorded by the data transfer means With time stamp means for adding a time stamp to Data transfer device. 3. An output unit for externally outputting the internal data received by the data receiving unit, an input unit for inputting the internal data externally output by the output unit, and returning the internal data input by the input unit. 3. The data transfer device according to claim 2, further comprising: a data return unit that performs the data return. 4. The data transfer device according to claim 3, further comprising comparison means for comparing the internal data transferred by the data transfer means with the internal data externally output by the output means. 5. The data transfer apparatus according to claim 4, wherein the data transfer means retransmits the internal data when the comparison result of the comparison means indicates a data mismatch. 6. An information requesting unit for requesting transmission of processing speed information indicating whether or not a remote device can complete data processing within a request period of a polling request. 6. The data transfer device according to claim 1, further comprising an information response unit that transmits processing speed information of the remote device when the transmission request is received. 7. When a polling request is issued to a remote device that cannot complete data processing within the polling request period, a dummy polling request is issued to a remote device that does not actually exist in advance. 7. A system according to claim 6, further comprising a dummy unit for issuing.
A data transfer device according to claim 1. 8. A data requesting step of issuing a polling request, a data storing step of periodically sampling external data and storing the external data in time series,
When a polling request is issued from the data request step, a data transmission step of transmitting external data stored in chronological order by the data storage step is provided,
A data transfer method for adding a time stamp to each external data transmitted from the data transmission step. 9. A data transfer step of broadcasting internal data and recording a time at the time of data transfer, a data request step of issuing a polling request when the data transfer step completes the broadcast transfer, and A data receiving step of receiving internal data broadcast-transferred from the step, a data storing step of periodically sampling external data and storing the external data in time series, and a polling request issued from the data requesting step And a data transmission step of transmitting external data stored in chronological order by the data storage step, wherein each of the data transmitted from the data transmission step based on the time at the time of data transfer recorded in the data transfer step Thailand for external data Data transfer method to add a time stamp. 10. While outputting the internal data received in the data receiving step to the outside, inputting the externally output internal data, returning the internal data, and transferring the internal data to the internal data and the data transfer step. The data transfer method according to claim 9, wherein internal data is compared. 11. An information requesting step for requesting transmission of processing speed information indicating whether or not a remote device can complete data processing within a polling request request cycle time; Providing an information response step of transmitting the processing speed information of the remote device upon receiving the transmission request of the remote device, and issuing a polling request to the remote device that cannot complete the data processing within the polling request period. 11. The data transfer method according to claim 8, wherein a dummy polling request is issued to a remote device that does not actually exist in advance.