JP2006197003A - Method of transmitting data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a data transmission system which improves the transfer rate of transient data without spoiling the punctuality of a cyclic transfer and can transfer a lot of transient data at a high speed. <P>SOLUTION: A method of transmitting data includes a step of judging whether the capacity of the above transient data to transmit is larger than the capacity of the above transient data area; a step of storing either one or both of update unnecessary area in which the time of the last data transmission and identical data are stored in an intact area, and the above cyclic data area which do not store the cyclic data in the transient data area and the above cyclic data area by dividing the transient data, when the capacity of the transient data to transmit is larger than the capacity of the transient data area; and a step of transmitting a data frame which stores the transients data at the time of the above transient data storing step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data transmission method, and more particularly, to a cyclic transmission method for periodically transferring data and a transient transmission method for irregularly transferring data to other devices.

  In recent years, as in the case of personal computers and the like, also in the field of FA equipment, network systems for communicating data by connecting the FA equipment to other devices have been used. Transmission systems used in such a network system include a cyclic transmission system and a transient transmission system.

  The cyclic transmission method is a one-to-N communication method, and since a data is transferred to all devices connected to the master station within a certain time, a certain amount of data communication is always performed regularly. On the other hand, the transient transmission method is a one-to-one communication method, in which data communication is performed only when data communication is necessary, and data communication is not performed during other times. In such a communication system, improvement in data transfer efficiency is an issue. For example, a data frame constituting one cycle is composed of a plurality of blocks each composed of a data character requiring high-speed communication and a data character capable of low-speed communication. However, data capable of low-speed communication is divided into a plurality of frames and there is a transmission technique (see, for example, Patent Document 1).

JP-A-5-244218

  By the way, the transmission system of the current network system is mainly a transmission system having both a cyclic transmission system and a transient transmission system. Among these transmission methods, in the transmission method that focuses on the periodicity of cyclic transmission, a cyclic transfer data area consisting of a bit transfer data area and a word transfer data area in the data frame, and a transient transfer data area There are transmission schemes in which fixed-length data frames that are clearly divided are used.

  Here, the cyclic transfer data area from the management device to the terminal device is divided into areas for the maximum number of stations in the system configuration in order to regularly and sequentially transfer data to all devices in the network system. Data transfer from the management device to the terminal device is performed by storing cyclic data addressed to each station in each cyclic transfer data area. If there is a transient transmission addressed to an arbitrary terminal device, the data is stored in the transient transfer data area and the frame is transmitted to all devices.

  Data transfer from the terminal device to the management device is performed by storing cyclic data addressed to the management device in the cyclic transfer data area. If there is a transient transfer addressed to an arbitrary terminal device, the data is stored in the transient transfer data area and the frame is transmitted to the management device. For example, when there are N terminal devices, each device is in the order of “management device → terminal device 1 → terminal device 2 → terminal device 3 →... Terminal device N−1 → terminal device N → management device”. By sequentially transferring frames, cyclic data is communicated at regular time intervals, and the periodicity of cyclic transmission is maintained.

  However, according to the above conventional technique, when transferring transient data exceeding the size of the transient transfer data area, only transient data having a capacity that can be stored in the transient transfer data area is stored in the frame, and the remaining transient data is stored. Data is sent to the next frame transfer. That is, when transferring a large amount of transient data exceeding the size of the transient transfer data area, the transient data is divided into a plurality of frames and transferred. For this reason, it takes a transfer time of "the entire system data transmission cycle time" x "transient data division count" to complete the transfer of the transient data, and there is a problem that high-speed transfer of the transient data cannot be performed. is there. Since the transfer time varies depending on the capacity of the transient data, there is no guarantee that the transient transmission can be maintained at a fixed time.

  When transmitting a large amount of transient data, it is possible to expand the size of the transient transfer data area and store more transient data. However, when transient data is stored with the size of the transient transfer data area expanded, the amount of data transferred in one cycle increases, and the periodicity of cyclic transfer defined by the system is impaired. is there.

  The present invention has been made in view of the above, and is a data transmission capable of improving the transfer rate of transient data and transferring a large amount of transient data at high speed without impairing the periodicity of cyclic transfer. The purpose is to obtain a method.

  In order to solve the above-described problems and achieve the object, a data transmission method according to the present invention uses cyclic transmission and transient transmission together in a data transmission system for transmitting information between a plurality of devices, and cyclic data. Is a data transmission method for transmitting information between devices using a data frame comprising a cyclic data area for storing transient data and a transient data area for storing transient data and constituting one cycle of transmission information. Transient data by dividing the transient data when the capacity of the transient data to be transmitted in the capacity determination process is larger than the capacity of the transient data area. D Stored in the unused area in which no cyclic data is stored in the cyclic data area and / or in the update unnecessary area in which the same data is stored as when data is transmitted in the cyclic data area. A transient data storing step, and a transmitting step of transmitting a data frame storing the transient data in the transient data storing step.

  According to the present invention, when the capacity of the transient data to be transmitted is larger than the capacity of the transient data area, the transient data is divided. The divided transient data is divided into a transient data area, an unused area where cyclic data is not stored in the cyclic data area, and an update unnecessary area where the same data is stored as when data is transmitted in the cyclic data area. Store and send to either or both.

According to the present invention, it is determined whether or not the capacity of the transient data to be transmitted is larger than the capacity of the transient data area, and the transient data is divided when the capacity of the transient data to be transmitted is larger than the capacity of the transient data area. The divided transient data can be divided into a transient data area, an unused area that does not store cyclic data in the cyclic data area, and an update unnecessary area that stores the same data as when data was transmitted in the cyclic data area. Since the data is stored and transmitted in one or both of them, the amount of transient data transferred in one cycle can be increased without impairing the periodicity of cyclic transfer, and the transfer speed of transient data can be improved. Kill. As a result, the present invention has an effect that it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the periodicity of cyclic transfer.

  Embodiments of a data transmission method according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

Embodiments In the present invention, the transient data transfer rate can be improved by increasing the size of transient data that can be transmitted in one frame. That is, in the present invention, as will be described below, attention is paid to the unused portion and the update unnecessary portion of the cyclic transfer data area of the frame, and transient data is stored in the unused portion and the update unnecessary portion of the cyclic transfer data area. To transfer data. As a result, a larger amount of transient data than before can be transferred in one frame, and the transfer rate of transient data can be improved.

  FIG. 1 is a diagram showing a schematic configuration of a data transmission network system using a data transmission method according to the present invention. As shown in FIG. 1, the data transmission network system according to the present embodiment is configured such that a management device 10 and a terminal device 20 are communicably connected via a network 30. In this system, a plurality of terminal devices 20 are connected, and each terminal device 20 is provided with a station number for communication identification. In FIG. 1, N is the maximum number of stations of the terminal device 20 as a network system. That is, this network system is configured to have N terminal devices 20 to 1 to 20-N. Here, the terminal devices 20-1 to 20-N are collectively referred to as the terminal device 20. In this data transfer system, frames are transferred between the management device 10 and the terminal device 20 via the network 30.

  FIG. 2 shows an example of the structure of a frame used for data transfer between the management device 10 and the terminal device 20 in the data transmission network system according to the present embodiment. The frame shown in FIG. 2 includes a frame unit 100, a cyclic transfer data area 200 that stores cyclic data, and a transient transfer data area 300 that stores transient data. The cyclic transfer data area 200 is divided into a bit transfer data area 201 and a word transfer data area 202.

  In the cyclic transfer data area 200, the bit transfer data area 201 and the word transfer data area 202 are provided with separate areas for storing data destined for the respective stations of the terminal device 20. That is, the bit transfer data area 201 includes a bit transfer data area 201-1 addressed to the station 1 to a bit transfer data area 201-N addressed to the station N as shown in FIG. The word transfer data area 202 includes a station 1-addressed word transfer data area 202-1 to a station-N-addressed word transfer data area 202-N as shown in FIG.

  FIG. 3 shows one cycle of the data transfer cycle on the data transmission network system. As shown in FIG. 3, each terminal device 20 sequentially transmits frames, whereby cyclic data is communicated at regular time intervals, and the periodicity of cyclic transmission is maintained.

  Next, processing when transient communication occurs from the management device 10 to the terminal device 20 in the data transmission network system according to the present embodiment configured as described above will be described. When a transient communication occurs from the management apparatus 10 to the terminal apparatus 20, first, information with a transient data and a destination are added to a header (not shown), and the transient data is stored in the transient transfer data area 300.

  Here, if the transient data has a size that does not exceed the capacity of the transient transfer data area 300, all the transient data is stored in the transient transfer data area 300 and the frame is transferred.

  On the other hand, if the transient data has a size exceeding the capacity of the transient transfer data area 300, only the transient data having a storable size is stored in the transient transfer data area 300 and the frame is transmitted. Carried over to the next frame transmission.

  FIG. 4 is a flowchart for explaining processing when transient communication from the management device 10 to the terminal device 20 occurs. Here, for example, the management device 10 to the terminal device 20 are not shown as main components, and a transmission / reception unit that transmits and receives frames, a storage unit that stores data and other various data, programs, and the size of transient data to be transferred Is a capacity determination unit that determines whether or not the capacity of the transient transfer data area is larger than the capacity of the transient transfer data area, a storage processing unit that stores various types of data in the frame, and data that is divided and transmitted is extracted from the frame In the following description, it is assumed that the apparatus includes a reconstruction unit that performs the reconstruction and a control unit that controls the entire apparatus.

  First, when transient data storage processing is started in the storage processing unit in the management apparatus 10 (step S101), the capacity of transmission data stored in the storage unit in the management apparatus 10, that is, the capacity of transient data to be transferred is the transient transfer data. It is determined whether or not the capacity is larger than the area 300 (step S102). Here, the capacity determination unit determines whether or not the capacity of the transient data to be transmitted is larger than the capacity of the cyclic transfer data area.

  If the transmission data size, that is, the size of the transient data to be transferred is smaller than the transient transfer data area 300 (No at step S102), the storage unit stores the transient data in the transient transfer data area 300 of the frame (step S103). The frame is transferred by the transmission / reception unit (step S104). Then, in the management device 10, the storage processing unit determines whether or not all the transient data to be transferred has been transferred (step S105). In this case, since all the transient data to be transferred has been transferred (Yes at step S105), a series of transfer processing ends.

  In step S102, when the transmission data size, that is, the size of the transient data to be transferred is larger than the capacity of the transient transfer data area 300 (Yes in step S102), the management apparatus 10 performs data storage processing on the transient data to be transferred. The part is divided (step S106). Then, the data storage processing unit stores the transient data divided within the size range of the transient transfer data area 300 in the transient transfer data area 300 (step S107), and the frame is transferred by the transmission / reception unit (step S104). Then, in the management device 10, the storage processing unit determines whether or not all the transient data to be transferred has been transferred (step S105).

  Here, since all the transient data to be transferred has not yet been transferred (No at Step S105), the process waits until the next transient communication (frame transfer) occurs (Step S108). Then, when the next transient communication (frame transfer) occurs, the transient data divided within the size range of the transient transfer data area 300 is stored in the transient transfer data area 300 (step S107), and the frame is transferred. (Step S104).

  Next, the management apparatus 10 determines whether or not all transient data to be transferred by the storage processing unit has been transferred (step S105). If it is determined that all the transient data to be transferred has been transferred (Yes at step S105), the series of transfer processing ends.

  On the other hand, when it is determined that all the transient data to be transferred has not been transferred (No at Step S105), the process waits again until the next transient communication (frame transfer) occurs (Step S108). By repeating the above processing, the transient data is divided into a plurality of frames and transferred. When the storage processing unit determines that all the transient data to be transferred has been transferred in step S105 (Yes in step S105), the series of transfer processing ends.

  Here, in this embodiment, in order to improve the transfer rate of transient data without impairing the periodicity of cyclic transfer, in addition to the above, an unused area in the cyclic transfer data area 200 or an update By storing transient data in an unnecessary area, data transfer that achieves both improvement of the transfer speed of transient data and securing of punctuality of cyclic transfer is realized. Hereinafter, the unused area and the update unnecessary area of the cyclic transfer data area for storing transient data in the present invention will be described.

The following four areas in the cyclic transfer data area 200 correspond to the unused areas.
(1) An unmounted area other than the actual cyclic data mounting area in the cyclic transfer data area 200 when the number of terminal devices 20 is less than the maximum number of devices on the system.
(2) A reserved area reserved for future expansion in the cyclic transfer data area 200.
(3) A word transfer data area 202 reserved for the terminal device 20 when there is a terminal device 20 that handles only bit data.
(4) A bit transfer data area 201 reserved for the terminal device 20 when there is a terminal device 20 that handles only word data.

  First, “(1) Unmounted area other than the actual cyclic data mounting area in the cyclic transfer data area 200 when the number of terminal devices 20 is less than the maximum number of devices on the system” will be described. To do. When the data transmission network system is constructed with the number of terminal devices less than the maximum number of devices on the system, the cyclic transfer data area 200 other than the cyclic data actual implementation station, that is, the actual implementation of cyclic data. The cyclic transfer data area 200 from the station to the largest station becomes an unused area.

  For example, FIG. 5 shows a case where the maximum number of actually mounted cyclic data stations is 17 and the maximum number of stations in the system is N. In this case, in the bit transfer data area 201 and the word transfer data area 202 of the cyclic transfer data area 200, the cyclic transfer data addressed to the station N from the cyclic transfer data area 200 (201, 202) addressed to the station 18. Area 200 (201, 202) becomes unused area A. In this case, the transient data can be divided and stored in the unused area A for transfer processing.

  As described above, when transmitting a large amount of transient data, it is necessary to transmit the transient data divided into a plurality of frames. At this time, it is possible to increase the size of the transient transfer data area and store more transient data. However, when transient data is stored with the size of the transient transfer data area expanded, the amount of data transferred in one cycle increases, and the periodicity of cyclic transfer defined by the system is lost.

  Therefore, as shown in FIG. 6, transient data is transferred in one cycle without impairing the periodicity of cyclic transfer by dividing and storing the transient data in the unused area A as described above and performing transfer processing. The amount of data can be increased to improve the transfer rate of transient data. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  Next, the above-mentioned “(2) Reserved area reserved for future expansion in the cyclic transfer data area 200” will be described. In the case where the network system is constructed with N terminal devices 20, if no cyclic data is mounted in all the cyclic transfer data areas 200 but the system is operating, the cyclic transfer data area 200 An unmounted data area is a reserved area. If there are reserved areas that are reserved for future expansion, these reserved areas become unused areas B in the cyclic transfer data area.

  For example, FIG. 7 shows a frame configuration in the case where a station 3, a station 4, a station N- 1, and a station N are designated as reserved stations (reserved areas) in a system composed of N devices. FIG. This reserved area is reserved as an area but is not used in data communication. In this case, the cyclic transfer data area 200 addressed to the station 3, addressed to the station 4, addressed to the station N-1, and addressed to the station N, more specifically, to the station 3, addressed to the station 4, addressed to the station N-1, The bit transfer data area 201 and the word transfer data area 202 addressed to and to the station N become the unused area B. Then, as shown in FIG. 8, the cyclic transfer data area 200 (reserved area) addressed to the station 3, which is the unused area B, addressed to the station 4, addressed to the station N-1, and addressed to the station N. The transient data can be divided and stored in the bit transfer data area 201 and the word transfer data area 202 addressed to the station 4, addressed to the station N-1, and addressed to the station N, and the transfer process can be performed.

  In this way, transient data is transferred in one cycle without impairing the periodicity of cyclic transfer by dividing and storing the transient data in the reserved area which is the unused area B as described above and performing transfer processing. The transfer rate of transient data can be improved by increasing the amount. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  Next, the “(3) word transfer data area 202 reserved for the terminal device 20 when there is a terminal device 20 that handles only bit data” will be described. The cyclic transfer data area 200 includes the bit transfer data area 201 and the word transfer data area 202 as described above. However, there are devices that do not use the word transfer data area 202 because some terminal devices 20 handle only bit data. When such a terminal device 20 exists, the word transfer data area 202 addressed to the terminal device that handles only bit data becomes an unused area.

  For example, FIG. 9 is a frame configuration diagram in the case where the system is composed of N devices, and the station 1, the station 2, the station 4, and the station N-1 are the terminal devices 20 that handle only bit data. . In this case, as shown in FIG. 9, the word transfer data area addressed to the station 1, addressed to the station 2, addressed to the station 4, and addressed to the station N-1, which is the word transfer data area 202 addressed to the terminal device handling only bit data. 202 is an unused area C. Then, as shown in FIG. 10, the transient data is divided and stored in the word transfer data area 202 addressed to the station 1, the station 2, the station 4, and the station N-1, which are unused areas C. It can be performed.

  As described above, the transient data is divided and stored in the word transfer data area 202 addressed to the station 1, the station 2, the station 4, and the station N−1 which are the unused areas C as described above and transferred. As a result, the amount of transient data transferred in one cycle can be increased and the transfer rate of transient data can be improved without impairing the periodicity of cyclic transfer. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  Next, “(4) the bit transfer data area 201 reserved for the terminal device 20 when there is a terminal device 20 that handles only word data” will be described. The cyclic transfer data area 200 includes the bit transfer data area 201 and the word transfer data area 202 as described above. However, depending on the terminal device 20, there is a device that does not use the bit transfer data area 201 because it handles only word data. When such a terminal device 20 exists, the bit transfer data area 201 addressed to the terminal device that handles only word data becomes an unused area.

  For example, FIG. 11 is a frame configuration diagram in the case where the system is configured by N devices, and the station 3, the station 5, and the station N-1 are the terminal devices 20 that handle only word data. In this case, as shown in FIG. 11, the bit transfer data area 201 addressed to the station 3, addressed to the station 5, and addressed to the station N-1, which is the bit transfer data area 201 addressed to the terminal device handling only word data, is not used. It becomes area D. Then, as shown in FIG. 12, transient data can be divided and stored in the bit transfer data area 201 addressed to the station 3, addressed to the station 5, and addressed to the station N-1, which are unused areas D, and transfer processing is performed. it can.

  In this way, by performing the transfer processing by dividing and storing the transient data in the bit transfer data area 201 addressed to the station 3, the station 5, and the station N-1, which are the unused areas D as described above. The transient data transfer rate can be increased by increasing the amount of transient data transferred in one cycle without impairing the periodicity of cyclic transfer. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  Next, the update unnecessary area of the cyclic transfer data area will be described. Since cyclic data is transferred to all devices within a certain period of time, a certain amount of data communication is always performed regularly. However, there is a high probability of transferring the same data to a device with little data change. There is no problem if the receiving device can detect data changes at regular intervals, and the transmitting device does not need to transmit the same cyclic data as in the previous communication. In this case, the cyclic transfer data area 200 that stores the same cyclic data as in the previous communication becomes an update unnecessary area.

  If the cyclic data to be transmitted to each station is the same as the transmission data at the previous communication, the transient data is divided into the cyclic transfer data area 200 that is an update unnecessary area instead of the cyclic data. Store.

  For example, regarding data transfer from the management device 10 to the terminal device 20 in a system composed of N devices, as shown in FIG. 13, the cyclic transfer data area 200 at the time of the previous communication and the latest communication cycle before the transfer. The click transfer data area 200 is compared. Here, the cyclic data to the station 3, the station 4, the station 6, and the station N are the same as the previous time, that is, to the station 3 and the station 4 in the cyclic transfer data area 200 of the latest communication before the transfer, The cyclic data stored in the cyclic transfer data area addressed to the station 6 and the station N and the cyclic data addressed to the station 3, the station 4, the station 6, and the station N in the cyclic transfer data area 200 at the previous communication It is assumed that the cyclic data stored in the transfer data area is the same.

  In this case, the cyclic transfer data area 200 (201, 202) addressed to the station 3, addressed to the station 4, addressed to the station 6, and addressed to the station N becomes the update unnecessary area E. Then, as shown in FIG. 14, the transient data is divided and stored in the cyclic transfer data area 200 addressed to the station 3, addressed to the station 4, addressed to the station 6, and addressed to the station N-1, which is the update unnecessary area E, and transferred. It can be performed.

  As described above, the transient data is divided and stored in the cyclic transfer data area 200 addressed to the station 3, the station 4, the station 6, and the station N, which are the update unnecessary areas E as described above. By doing so, the amount of transient data transferred in one cycle can be increased without impairing the periodicity of cyclic transfer, and the transfer rate of transient data can be improved. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  Further, when data transfer from the terminal device 20 to the management device 10 occurs, as shown in FIG. 15, the cyclic transfer data area 200 (201, 202) at the previous communication and the latest communication cyclic before the transfer are shown. The transfer data area 200 (201, 202) is compared. Here, the cyclic data to the management device 10 is the same as the previous one, that is, the cyclic data in the latest transfer cyclic transfer data area 200 (201, 202) before the transfer and the cyclic transfer at the previous communication. It is assumed that the cyclic data stored in the data area 200 (201, 202) is the same. In this case, the cyclic transfer data area 200 (201, 202) becomes the update unnecessary area F. Then, as shown in FIG. 16, the transient data can be divided and stored in the cyclic transfer data area 200 (201, 202), which is the update unnecessary area F, and the transfer process can be performed.

  As described above, the transient data is divided and stored in the cyclic transfer data area 200 (201, 202), which is the update unnecessary area F as described above, and the transfer processing is performed, thereby impairing the periodicity of the cyclic transfer. Without increasing the amount of transient data transferred in one cycle, the transfer rate of transient data can be improved. As a result, it is possible to perform a transfer process that achieves both improvement in the transfer rate of transient data and ensuring the punctuality of cyclic transfer.

  In addition, as described above, when transient data is embedded in an unused area or an update unnecessary area of the cyclic transfer data area 200 and frame transfer is performed, whether or not the transient data is inserted in the cyclic transfer data area 200. Thus, a transient data insertion presence / absence flag indicating whether or not transient data is inserted in the cyclic transfer data area 200 is provided in the transient transfer data area 300 to transfer the frame.

  Then, in the apparatus that has received the frame, when the destination of the transient data is the local station, the presence / absence of a transient data insertion presence / absence flag indicating that the transient data is stored in the cyclic transfer data area 200 is determined. If it is determined by the transient data insertion presence / absence flag that the transient data is stored in the cyclic transfer data area 200, the transient data is extracted from the cyclic transfer data area 200 (201, 202), and the data and the transient data are extracted. Transient data is reconstructed from the transient data stored in the transfer data area 300.

  For example, in the device that receives the frame, when the destination of the transient data is the local station, as shown in FIG. 17, a flag 301 indicating that the transient data is stored in the bit transfer data area 201, and the word transfer It is determined whether or not there is a flag 302 indicating that transient data is stored in the data area 202. If it is determined by these flags that transient data is stored in the bit transfer data area 201 or the word transfer data area 202, the data is extracted from the cyclic transfer data area 200 (201, 202) and the data is extracted. And the transient data stored in the transient transfer data area 300 are reconstructed. If transient data is stored in the cyclic transfer data area of the local station, it is determined that the data is the same as the previously transferred data, and the cyclic data is not updated.

  As described above, frame data is transferred by embedding transient data in unused areas or update unnecessary areas of the cyclic transfer data area 200, so that the transient transfer data area is increased in size without increasing the size of the transient transfer data area. Since the data can be stored and transmitted in a frame, the transient data transfer rate can be improved without impairing the periodicity of cyclic transfer.

  As described above, the data transmission method according to the present invention is useful for a transmission method having both a cyclic transmission method and a transient transmission method, and is particularly suitable for transmitting a large amount of transient data.

It is a figure which shows schematic structure of the data transmission network system using the data transmission method concerning this invention. It is a figure which shows an example of the structure of the flame | frame used for the transfer of the data between a management apparatus and a terminal device in the data transmission network system concerning this Embodiment. It is the figure showing 1 cycle of the data transfer cycle on a data transmission network system. It is a flowchart explaining a process when transient communication generate | occur | produces from a management apparatus to a terminal device. It is a data frame block diagram which showed the unused area in a cyclic transfer data area. It is a data frame block diagram which shows the state which stored the transient data in the unused area in a cyclic transfer data area. It is a data frame block diagram which showed the reservation area in a cyclic transfer data area. It is a data frame block diagram which shows the state which stored the transient data in the reservation area in a cyclic transfer data area. It is a data frame block diagram which showed the unused area in a cyclic transfer data area. It is a data frame block diagram which shows the state which stored the transient data in the unused area in a cyclic transfer data area. It is a data frame block diagram which showed the unused area in a cyclic transfer data area. It is a data frame block diagram which shows the state which stored the transient data in the unused area in a cyclic transfer data area. It is the data frame block diagram which showed the cyclic transfer data area at the time of the last communication compared, and the cyclic transfer data area of the newest communication before transfer. It is a data frame block diagram which shows the state which stored the transient data in the cyclic transfer data area of the latest communication before transmission. It is the data frame block diagram which showed the cyclic transfer data area at the time of the last communication compared, and the cyclic transfer data area of the newest communication before transfer. It is a data frame block diagram which shows the state which stored the transient data in the cyclic transfer data area of the latest communication before transmission. FIG. 5 is a data frame configuration diagram showing a state in which a flag indicating that transient data is stored in the bit transfer data area and a flag indicating that transient data is stored in the word transfer data area are provided in the transient transfer data area. is there.

Explanation of symbols

10 management device 20 terminal device 100 frame 200 cyclic transfer data area 201 bit transfer data area 202 word transfer data area 300 transient transfer data area 301 flag 302 flag

Claims (7)

In a data transmission system that transmits information between multiple devices, it uses both cyclic transmission and transient transmission, and consists of a cyclic data area that stores cyclic data and a transient data area that stores transient data. A data transmission method for transmitting information between devices using data frames constituting information,
A capacity determination step of determining whether or not the capacity of the transient data to be transmitted is larger than the capacity of the transient data area;
When the capacity of the transient data transmitted in the capacity determination step is larger than the capacity of the transient data area, the transient data is divided and cyclic data is stored in the transient data area and the cyclic data area. A transient data storage step for storing in an unused area and one or both of the update unnecessary areas in which the same data as the previous data transmission was stored in the cyclic data area, and
A transmission step of transmitting a data frame storing transient data in the transient data storage step;
A data transmission method comprising: In the case where the number of the devices is less than the maximum number of devices in the data transmission system,
The data transmission method according to claim 1, wherein an area other than an actual cyclic data mounting area in the cyclic data area is used as the unused area. The data transmission method according to claim 1, wherein a reserved area reserved in a cyclic data area for data transmission system expansion is used as the unused area. In the case where there is a device that handles only bit data among the cyclic data as the device,
The data transmission method according to claim 1, wherein a word data storage area in the cyclic data area reserved for a device that handles only the bit data is used as the unused area. In the case where there is the device that handles only word data among the cyclic data as the device,
The data transmission method according to claim 1, wherein a bit data storage area in the cyclic data area reserved for a device that handles only the word data is used as the unused area. Between the transient data storage step and the transmission step,
2. The data transmission method according to claim 1, further comprising a flag setting step of setting a flag indicating that the divided transient data area is stored in the cyclic data area in the transient data area. When the apparatus that has received the data frame determines that transient data is stored in the cyclic data area based on the presence or absence of the flag, the transient data stored in the cyclic data area and the transient data area are stored in the cyclic data area. The data transmission method according to claim 6, wherein the data transmission method is taken out and reconstructed.

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