JP4696998B2 - Data communication system and data transmission method - Google Patents

Description

  The present invention relates to a data communication system and a data transmission method for transmitting data generated in a time series by a client device to a host device via a communication line.

  A technique for reducing traffic by compressing data flowing through a communication line is disclosed (for example, see Patent Document 1).

  FIG. 8 is a functional block diagram showing a configuration example of a conventional data communication system. A client device 1 comprising a plurality of industrial instruments (differential pressure gauges, flow meters, thermometers, etc.) 11, 12, 13, 14, 15... Is sent to a single host device 3 via a common communication line 2 in time series data. The plant environment which transmits is shown.

  The host device 3 having a communication form represented by fieldbus communication and all industrial instruments connected to the system use the single communication line 2 to transmit / receive necessary information.

  For example, the host device 3 acquires process data and alarm information held by an industrial instrument connected to the system in consideration of priority and synchronism with time. The industrial instrument acquires time information and the like managed by the host device 3. Furthermore, various information is also transmitted and received between a plurality of industrial instruments.

  For example, the data A transmitted from the industrial instrument 11 to the host device 3 includes time series data D1 (A11, A12, A13... A1n) and time series data D2 (A21, A22, A23... A2n), time series data D3 (A31, A32 A33... A3n), and time data Tm for each data transmission to be communicated separately. The time series data D1 to D3 are transmitted in series.

  FIG. 9 is an image diagram of data transmission from the client device 1 to the host device 3. The host device 3 that has received the time-series data by frequent communication collects this as time-series information and processes it according to the application.

  FIG. 10 is an example of a time-series information holding table in which the time-series data D11 to D3 collected by the host device 3 are classified and held for each data type.

  FIG. 11 is a functional block diagram of application software that operates in the host device 3 that receives time-series data transmitted from the client device via the controller 4. 31 is a data collecting means, 32 is a GUI means such as a data display or trend screen, 32 is an alarm judging means, and 34 is an acquired data calculating means.

JP 11-341107 A JP 2005-032086 A JP 2001-313659 A JP 2001-092777 A JP 07-059175 A Japanese Patent Laid-Open No. 08-008842 JP 2000-068553 A

The conventional data communication system has the following problems.
(1) Industrial meters send and receive a lot of information using a single communication line. When the host device acquires time-series information related to data A of an industrial instrument connected to the system, the host device 3 needs to periodically receive the data A of the industrial instrument using the communication line 2.

(2) In order to obtain n pieces of time-series information of data A, the host device and the industrial instrument must perform communication n times in order to obtain this data A. Moreover, in order to acquire other data T (for example, time information etc.), the communication for that must also be implemented.

(3) When it is desired to acquire time-series information in a short cycle, the host device 3 needs to frequently receive data A. However, other data and other industrial instrument information must also be transmitted / received using this communication line 2. When communication is performed in consideration of the priority and synchronism of other data, data A is transmitted in a short cycle. It is difficult to keep getting at.

(4) In addition, when the data A is repeatedly transmitted and received in a short cycle, the number of communication during that time increases, so the communication load increases. However, in practice, there are many opportunities to obtain time series information of a plurality of data and time information at that time from one industrial instrument.

(5) For example, in the host device 3, not only the process value of the industrial instrument but also the data processing such as moving average and sum of squares after directly monitoring the pressure, temperature, flow rate signal, signal from the sensor, etc. For example, it is possible to carry out diagnosis of industrial instruments using the ones that have been subjected to.

(6) Usually, such data collection often uses signals other than signals used in control operation, and the data collection cycle is performed at intervals of several seconds (about 5 seconds) for each parameter per device. . Therefore, if 100 pieces of time-series information are acquired for one type of information other than the process value, 500 seconds (8 minutes) are required to acquire the one type of information.

(7) As a measure to avoid communication load by acquiring time-series information, an array-type buffer is provided inside the industrial instrument, holds the time-series information as one array parameter, and transmits data to the host device via communication. There is also a technology.

(8) In order to acquire time-series information regarding a plurality of data having different types, it is necessary to prepare a plurality of array parameters. In addition, when you want to obtain the time information at that time, since there is a dedicated type of time information, you must provide a separate parameter, and you must provide a number of array parameters for each data type and type. Don't be.

  The present invention has been made to solve the above-described problems. The host device does not frequently communicate with the client device, and the time series information of the plurality of data held by the client device and the time information at that time are provided. It aims at realizing the data communication system which enables acquisition of.

In order to achieve such a subject, the present invention has the following configuration.
(1) In a data communication system in which data generated in a time series by a client device is transmitted to a host device via a communication line, the client device converts the data block into character string information. Means, buffer means for holding the converted character string information, and transmission means for transmitting the character string information held in the buffer means to the host device, wherein the host device receives the character from the client device. A data communication system comprising: data collection means for obtaining column information; and decoding means for dividing the obtained character string information for each data size and returning the original data.
(2) The data communication system according to (1), wherein the data type conversion unit converts the generated data into different character types and converts the data into one character string information.
(3) The data communication system according to (1) or (2), wherein the decoding unit divides the acquired character string information for each data size and data type and restores the original data.
(4) The client device includes buffer function operation means for operating validity / invalidity of the buffer means based on a command from the host device. Data communication system.
(5) The data communication system according to any one of (1) to (4), wherein the client device includes data reference means that can refer to the contents of the buffer means from an external device.
(6) The data communication system according to any one of (1) to (5), wherein the client device is an industrial instrument that measures a physical quantity of a process.
(7) a data type conversion step for converting a block of data generated in a time series by the client device into character string information, a holding step for holding the converted character string information in the buffer means, and the held characters A data transmission method comprising: a transmission step of transmitting column information to a host device; and a decoding step of dividing character string information acquired by the host device for each data size and returning it to the original data.

As is apparent from the above description, the present invention has the following effects.
(1) By holding time series information of data A for a certain period of time as a block of character strings, the host device needs to frequently communicate with the industrial meter to obtain data A information. Disappears.

(2) Blocking multiple time-series information related to data A and defining it as a single character string information AA makes it possible to acquire data that had to be communicated n times in the prior art in one communication. It becomes possible to do. As a result, the number of communications between the host device and the industrial instrument is reduced, and the communication load is also reduced.

(3) By defining data as one piece of character string information AA that is not an array, it is usually possible to obtain information that is separately defined in different types as one piece of character string information.

(4) By defining the data as one character string information AA that is not an array or structure, even for a single data, data must be obtained via communication for each member of the array or structure. Even in a host device having an indispensable communication system, data can be acquired by one communication.

(5) For example, in the case of using fieldbus communication, in general, there is a restriction on the member configuration of the structure as one of the standard specifications. However, if data is defined as one piece of character string information AA, it can be incorporated into the character string information AA without being limited to the type of data desired to be acquired.

(6) The time information incorporated in the character string information AA can always be acquired as a value synchronized with the time series information.

(7) By providing means for enabling / disabling the time-series information holding function, it is possible to avoid holding unnecessary information when this function is unnecessary.

(8) Since the data A is stored in the industrial instrument without using communication, the information of the data A can be collected while other data is being transmitted / received.

(9) The operation cycle for calculating the process value executed in the industrial instrument is about several hundreds msec, which is much faster than the data acquisition cycle (about 5 sec) via the communication server. The host device can acquire the time series data acquired at 100 msec intervals by one communication.

(10) Moreover, if the time series information of a plurality of data is held in the industrial instrument, a plurality of time series information can be acquired at once.

  The present invention will be described in detail below with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a data communication system to which the present invention is applied. Hereinafter, the characteristic part added by this invention is demonstrated.

  Reference numeral 100 denotes a client device (an industrial instrument or the like) to which the present invention is applied. Reference numeral 300 denotes a host device, which acquires time-series data converted into character string information AA from the client device 100 via the communication line 2.

  In the client device 100, reference numeral 101 denotes time-series data generating means that processes process physical quantity measurement values and generates time-series data. Reference numeral 102 denotes data type conversion means that blocks time-series data generated during a predetermined period and converts it into character string information. For example, when the C language is used, the data can be converted into a character string by using a standard library function (memcpy).

  Reference numeral 103 denotes buffer means for temporarily storing the converted character string information. Reference numeral 104 denotes transmission means, which acquires character string information temporarily held based on a transmission request from the buffer means host device 300 or automatically when the buffer means 103 is accumulated for a predetermined period. To send.

  The transmission unit 104 clears the contents of the buffer unit 103 after transmission. By this clearing process, the buffer means 103 starts accumulating time-series data for the next transmission cycle converted into the character string information.

  Reference numeral 105 denotes data reference means that reads and provides character string information held in the buffer means 103 to an external device for maintenance connected to the communication line 2. Reference numeral 106 denotes a buffer function operating means that operates the temporary holding function of the buffer means 103 based on a command from the host device 300.

  In the host device 300, 301 is a data collection unit that outputs a data transmission request to the client device 100, and acquires and holds character string information transmitted from the transmission unit 104 based on this request.

  A decoding unit 302 executes data processing for dividing the collected character string information for each data size and restoring the original data. When the character string information has a plurality of different data types, the acquired character string information is divided for each data size and data type and returned to the original data. The divided time series data is transferred to and held in the divided data holding unit 303.

  The decoding means 302 has a function of determining the information and data type acquired from the industrial instrument in the processing portion of the acquired character string information, and correctly dividing it into different data sizes for each data type. A standard conversion tool can be used to convert the character string information into the divided numerical data.

  Since the decoding means 302 can acquire and decompose a plurality of types of data types, it can also obtain accurate time information actually acquired by an industrial instrument by including time information as a data type.

  Reference numeral 304 denotes a buffer function command unit that commands the buffer function operation unit 105 of the client device 100 to validate or invalidate the temporary holding function of the buffer unit 103.

  FIG. 2 is a functional block diagram showing a specific configuration example of the data communication system of the present invention that transmits time series data from an industrial instrument to the host device 300, corresponding to the conventional system described in FIG.

  Data transmitted from the industrial instrument 11 to the host device 300 at one time includes time-series data D1 (A11, A12, A13... A1n) and time-series data D2 (A21, A22, A23) generated in a predetermined period for each data type. ... A2n), time series data D3 (A31, A32 A33... A3n) and transmission time data Tn are treated as one block, a series of time series data and time data are converted into one character string information AA, and time Tn Is sent to the host device 300 in one transmission.

  In this way, by passing the time-series data D1 to D3 to the host device 300 at a time in one transmission, frequent transmission as in the conventional data communication system is unnecessary, and the load on the communication line 2 is greatly reduced. can do.

  FIG. 3 is an image diagram of data transmission from the client device 100 to the host device 300 according to the present invention, corresponding to the image of the conventional system described in FIG. Industrial equipment stores time-series information of data internally.

  When information for a certain period of time is accumulated, or in response to a transmission request from the host device, the character string information is passed to the host device 300 in a single transmission. The host device 300 decodes the acquired character string information, decomposes it into the original time series data, and processes this according to the application.

  FIG. 4 is a transition diagram illustrating a process of decomposing character string information acquired by the host device 300. In the character string information AA to be acquired, time series data having a plurality of data types and transmission time information Tn are held in one table.

  The decoding means 302 of the host device 300 sequentially acquires the character string information of this table from the top in the order of the data type, divides it into data sizes determined by the data type, and decomposes it into the original time series data for each data type. To restore the original time series data.

  FIG. 5 is a time chart for explaining the transmission procedure of the data transmission method of the present invention. In the data type conversion step, the time series data A1 to An generated at times T1 to Tn in the client device 100 are sequentially converted into character string information. In the holding step, the converted character string information is sequentially added to the buffer means 103 and stored.

  In the transmission step, the character string information held in the buffer means 103 is transmitted to the host device 300 all at once based on the transmission request received from the host device 300 at time t1. In the decoding step in the host device 300, the obtained character string information is divided into data types and sizes by the function of the decoding means 302 and decomposed into original data.

  FIG. 6 is a functional block diagram of application software running in the host device 300 corresponding to the conventional system of FIG. In addition to the configuration of the data collection means 31, the GUI means 32, the alarm determination means 32, and the acquired data calculation means 34, which have the same functions as the conventional system, a decoding means 302 is provided.

  FIG. 7 is a connection image diagram of an external device via the communication line 2. If the time-series data for a certain period of time in the industrial instrument is held in the form of character string information, even if it is not a system that constantly monitors the apparatus, such as the host apparatus 300, a certain amount of time can be obtained in one communication. It becomes possible to acquire the time series information.

  Therefore, when an abnormal condition occurs or during maintenance, the maintenance tool 400 or PC 500 temporarily connected to the communication line 2 is used to not only detect the current industrial instrument information and status, but also grasp past data trends. And history information can be acquired.

  In addition, fieldbus communication, which is a typical communication form, is provided with a trend function as one of its specifications. It can be used for a certain period (16 units) from systems other than the system that constantly monitors industrial instruments such as host equipment. ) Time series information can be acquired.

  However, with the present invention, depending on the definition of industrial instruments, it is possible to acquire several hundred pieces of time-series information at a time, and it is expected to be extremely advantageous for grasping trends from past data. The

  In the embodiment described above, the industrial instrument is exemplified as the client device 100 and the transmission of the time series data generated from the measurement of the process has been described. However, the client device of the present invention is not limited to the industrial instrument, This can be applied to general data communication in which data generated in time series is transmitted to a host device using a predetermined communication protocol, and can contribute to reducing the load on the communication line.

It is a functional block diagram which shows one Embodiment of the data communication system to which this invention is applied. It is a functional block diagram which shows the specific structural example of the data communication system of this invention. It is an image figure of data transmission from the client device to the host device in the present invention. It is a transition diagram explaining the decomposition | disassembly process of the character string information which a host apparatus acquires. It is a time chart explaining the transmission procedure of this invention data transmission method. It is a functional block diagram of application software that operates in a host device. It is a connection image figure of the external apparatus via a communication line. It is a functional block diagram which shows the structural example of the conventional data communication system. It is an image figure of the data transmission from a client apparatus to a host apparatus. It is a time series information holding table that holds time series information collected by a host device by classifying it by data type. It is a functional block diagram of application software that operates in a host device.

Explanation of symbols

2 Communication Line 100 Client Device 101 Time Series Data Generation Unit 102 Data Type Conversion Unit 103 Buffer Unit 104 Transmission Unit 105 Data Reference Unit 106 Buffer Function Operation Unit 300 Host Device 301 Data Collection Unit 302 Decoding Unit 303 Divided Data Holding Unit 304 Buffer Function Command means

Claims (7)

In a data communication system that transmits data generated in a time series by a client device to a host device via a communication line,
The client device includes data type conversion means for converting the block of data into character string information, buffer means for holding the converted character string information, and character string information held in the buffer means as the host device. Transmission means for transmitting to
The host device includes data collecting means for acquiring the character string information from the client device, and decoding means for dividing the acquired character string information for each data size and returning it to the original data. Communications system. The data communication system according to claim 1, wherein the data type conversion unit converts the generated data into different character types and converts the data into one character string information. 3. The data communication system according to claim 1, wherein the decoding unit divides the acquired character string information for each data size and data type and restores the original data. 4. The data communication system according to claim 1, wherein the client device includes a buffer function operation unit that operates the buffer unit to be valid / invalid based on a command from the host device. . 5. The data communication system according to claim 1, wherein the client device includes a data reference unit that can refer to the contents of the buffer unit from an external device. 6. The data communication system according to claim 1, wherein the client device is an industrial instrument that measures a physical quantity of a process. A data type conversion step for converting a block of data generated in a time series by a client device into character string information;
A holding step for holding the converted character string information in the buffer means;
A transmission step of transmitting the held character string information to the host device;
A data transmission method comprising: a decoding step of dividing character string information acquired by a host device into data for each size and returning the original data.

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