JP4292838B2 - Multi-point data collection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a plurality of measurement modules that measure according to a measurement start command from a main module and output measurement data to the main module, and the main module and the plurality of measurement modules are connected by a dedicated bus. More particularly, the present invention relates to a multipoint data collection device that ensures temporal alignment of measurement data between measurement modules.
[0002]
[Prior art]
When measuring signals of various physical quantities such as voltage, resistance, temperature, etc., data is collected by assigning functions to each module and measuring with a plurality of modules. Even when measuring signals of the same physical quantity, if there are a large number of measurement points, measurement is performed using a plurality of modules having the same function and data is collected. A multipoint data collection device is a unit in which these modules are combined into a single unit using a dedicated internal bus, for example, a serial bus (for example, Non-Patent Documents 1 to 3).
[0003]
FIG. 4 is a block diagram showing a conventional example of such a multipoint data collection apparatus.
In FIG. 4, an internal serial bus (dedicated bus) 10 is a single system serial bus and is a signal line through which serial data is transmitted. For example, serial data is transmitted to the internal serial bus 10 according to the RS485 interface standard.
[0004]
The measurement modules M <b> 1 and M <b> 2 are modules that perform measurement, have a measurement module communication processing unit 21 and a measurement unit 22, and are connected to the internal serial bus 10. The communication processing unit 21 is connected to the internal serial bus 10 and transmits / receives serial data. The measurement unit 22 performs measurement by connecting a sensor (not shown) such as a voltage measurement probe, a temperature measurement thermocouple, a resistance temperature detector, and the like. The measurement unit 22 is connected to the communication processing unit 21 and performs measurement, setting of measurement conditions, and the like according to the content of serial data received by the communication processing unit 21, and outputs measurement data to the communication processing unit 21.
[0005]
The main module 30 includes a CPU (Central Processing Unit) 31, a main module communication processing unit 32, and a memory 33, and is connected to the internal serial bus 10. In addition, the main module 30 performs measurement condition setting, measurement start, measurement end instruction, measurement data collection, and the like to the measurement modules M1 and M2 via the internal serial bus 10 to control the entire multipoint data collection apparatus. Do. Further, the main module 30 exchanges data with a personal computer (not shown) provided outside.
[0006]
The CPU 31 is a data processing unit that controls the main module 30 as a whole, and also instructs the communication processing unit 32 to set measurement conditions, start measurement, and end measurement, or to transmit measurement data received by the communication processing unit 32. Perform data processing.
[0007]
The communication processing unit 32 is connected to the internal serial bus 10 and serially communicates with the desired measurement modules M1 and M2 via the internal serial bus 10 in accordance with settings and instructions from the CPU 31.
[0008]
The memory 33 stores the measurement data from the communication processing unit 32 and the names of the measurement modules M1 and M2, and outputs the stored measurement data and measurement modules M1 and M2 to the CPU 31.
[0009]
The internal serial bus 10 is a single-system serial bus, and the measurement modules M1 and M2 and the main module 30 share one serial bus 10. Accordingly, bidirectional communication between the main module 30 and the measurement modules M1 and M2, and the main module 30 cannot communicate simultaneously with the plurality of measurement modules M1 and M2.
The reason why the multipoint data collection device has such a configuration is that it is very important to reduce the size and cost. If a plurality of serial buses are provided, it is necessary to provide a plurality of communication processing units 32 also in the main module 30, and not only the main module 30 but also the entire apparatus is increased in size, resulting in an increase in the number of parts and cost. End up. In particular, when measuring a high voltage, it is necessary to provide insulation between the measurement modules M1 to M3 and the main module 30 in order to achieve a high breakdown voltage. Must be a serial bus.
[0011]
The dedicated internal serial bus 10 has almost no difference in physical distance between the measurement modules M1 and M2 and the main module 30, can communicate at a constant transmission speed, and the transmission time is almost constant. .
[0012]
The operation of such an apparatus will be described. FIG. 5 is a timing chart showing the operation of the apparatus shown in FIG.
First, the operation of the main module 30 will be described.
Measurement timing occurs at each measurement interval ΔTm, and the main module 30 outputs a measurement start command to each of the measurement modules M1 and M2. That is, the CPU 31 of the main module 30 outputs a measurement start command to the communication processing unit 32 with the measurement module M1 as a transmission destination. Thereby, the communication processing unit 32 converts the command into serial data and transmits it to the measurement module M1 (S10). After completing the command transmission to the measurement module M1, the CPU 31 similarly causes the communication processing unit 32 to transmit a measurement start command with the measurement module M2 as a transmission destination (S11).
[0013]
Subsequently, the operation of the measurement modules M1 and M2 will be described.
The communication processing unit 21 of the measurement modules M1 and M2 extracts a measurement start command from the received serial data and outputs the command to the measurement unit 22. And the measurement part 22 measures according to this command. When this measurement is completed, the measured data is output to the communication processing unit 21. Further, the communication processing unit 21 converts the measurement data into serial data and transmits it to the main module 30 (S12, S13).
[0014]
The operation of the main module 30 will be described again.
The communication processing unit 32 receives serial data from the measurement module M1 (S12). Then, the measurement data is extracted from the received serial data, and the measurement data and the name of the measurement module M1 that transmitted the measurement data are paired and stored in the memory 33. Similarly, serial data is received from the measurement module M2 (S13). Then, the measurement data is extracted from the received serial data, and the measurement data and the name of the measurement module M2 that has transmitted the measurement data are paired and stored in the memory 33.
[0015]
Of course, when the measurement interval ΔTm elapses, the measurement start command is similarly transmitted to the measurement modules M1 and M2 (S10 and S11), and the measurement data is received from the measurement modules M1 and M2 (S12 and S13). repeat.
[0016]
When the measurement data for a predetermined number of times is collected, the CPU 31 reads out the measurement data and the names of the measurement modules M1 and M2 from the memory 33 and performs data processing. At this time, time alignment (temporal synchronization) between the measurement modules M1 and M2 is performed based on the order stored in the memory 33, that is, the order in which the main module 30 receives the measurement data from the measurement modules M1 and M2. Plan data processing.
[0017]
Note that the CPU 31 of the main module 30 sets the same measurement conditions in advance in the measurement modules M1 and M2 via the communication processing unit 32 when the apparatus is initialized, for example.
[0018]
[Non-Patent Document 1]
Tetsuya Sato, 1 other "Data Acquisition Unit DARWIN (registered trademark) series", Yokogawa Technical Journal, Yokogawa Electric Corporation, 1996, Vol. 40, No. 3, p. 95-98
[Non-Patent Document 2]
Kasashima and three others “DARWIN Series Hybrid Recorder DR230 / 240”, Yokogawa Technical Journal, Yokogawa Electric Corporation, 1997, Vol. 41, No. 3, p. 73-76
[Non-Patent Document 3]
Kuribayashi and two others "DARWIN Series Data Collector DC100", Yokogawa Technical Journal, Yokogawa Electric Corporation, 1998, Vol. 42, No. 3, p. 219-222
[0019]
[Problems to be solved by the invention]
In this way, a measurement start command is output at the same measurement interval ΔTm to each of the measurement modules M1 and M2 connected by the internal serial bus 10, and measurement data is collected. Then, the measurement data from the measurement modules M1 and M2 is subjected to data processing with a temporal alignment based on the order of reception. Of course, in general, the reference time for data processing is based on the time when the measurement is started, but the measurement is performed at the same measurement interval ΔTm, and data is transmitted via the dedicated internal serial bus 10. Since the collection is performed, the same thing can be achieved based on the order of reception.
[0020]
However, when the measurement object is different between the measurement modules M1 and M2, the optimum measurement interval is also different. For example, a voltage measurement of an electronic circuit with a fast temporal variation has a short measurement interval (for example, 100 [ms]), and a temperature measurement with a slow temporal variation has a long measurement interval (for example, a 2 [s] interval. ).
[0021]
For example, if the measurement interval of the measurement module M1 is 100 [ms] and the measurement interval of the measurement module M2 is 2 [s], the measurement module M2 performs a measurement once and transmits measurement data to the main module 30. The measurement module M1 transmits measurement data 20 times. Since the main module 30 performs data processing based on the order in which the measurement data is received, there is a problem that the measurement data between the measurement modules cannot be temporally aligned due to a deviation from the actual measurement start order. was there.
[0022]
Therefore, an object of the present invention is to realize a multi-point data collection apparatus that ensures time alignment of measurement data between measurement modules.
[0023]
[Means for Solving the Problems]
The invention described in claim 1
A multi-point data collection device comprising a plurality of measurement modules for measuring according to a measurement start command from a main module and outputting measurement data to the main module, wherein the main module and the plurality of measurement modules are connected by a dedicated bus In
The measurement interval differs between the measurement modules,
The main module adds the time information to the measurement start command based on the measurement interval of each of the measurement modules, and individually designates and outputs the measurement module as the transmission destination.
The measurement module adds time information added to the measurement start command to measurement data measured after receiving the measurement start command, and outputs the measurement data to the main module ,
The dedicated bus is a serial bus shared by the main module and the plurality of measurement modules .
[0024]
The invention according to claim 2 is the invention according to claim 1,
The main module
A time output means for outputting time information;
Adding a time information of the time output means, a communication processing unit for exchanging data with the plurality of measurement modules via the dedicated bus;
It is characterized by having.
[0025]
The invention according to claim 3 is the invention according to claim 2,
The main module
Data processing means for rearranging the measurement data in time order from the time information added to the measurement data is provided.
[0026]
The invention according to claim 4 is the invention according to any one of claims 1 to 3,
The measurement module
A communication processing unit for exchanging data with the main module via the dedicated bus;
A measurement unit that holds time information from the communication processing unit, performs measurement according to a measurement start command, adds the held time information to the measured measurement data, and outputs the measurement data to the communication processing unit. It is characterized by having.
[0027]
The invention according to claim 5 is the invention according to claim 2 or 3 ,
The time output means of the main module is a counter that increments a count value at a predetermined interval and outputs the count value as time information.
[0028]
The invention according to claim 6 is the invention according to claim 5,
The counter is characterized in that the predetermined interval is at most the measurement interval of the measurement module.
[0029]
The invention according to claim 7 is the invention according to claim 2 or 3 ,
The time output means of the main module outputs time as time information.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention. Here, the same components as those in FIG. In FIG. 1, a main module 40 is provided instead of the main module 30. In addition, a buffer 23 is newly provided in the measurement unit 22 of the measurement modules M1 and M2.
[0031]
The main module 40 includes a counter 41, a CPU 42, a communication processing unit 43, and a memory 44, and is connected to the internal serial bus 10. In addition, the main module 40 performs measurement condition setting, measurement start, measurement end instruction, measurement data collection, and the like to the measurement modules M1 and M2 via the internal serial bus 10 to control the entire multipoint data collection apparatus. Do. Further, the main module 40 exchanges data with a personal computer (not shown) provided outside.
[0032]
The counter 41 is a time output means, and increments a counter number that is a count value at a predetermined interval, and outputs this counter number as time information. The CPU 42 is a data processing means that controls the entire main module 40 and also instructs the communication processing unit 43 to set measurement conditions, start measurement, and end measurement, or to transmit measurement data received by the communication processing unit 43. Perform data processing.
[0033]
The communication processing unit 43 is connected to the internal serial bus 10, and transmits and receives serial data via the internal serial bus 10 with the desired measurement modules M 1 and M 2 according to the counter number output from the counter 41, the setting from the CPU 42, and the instruction. Perform serial communication. The memory 44 is a storage unit that stores measurement data from the communication processing unit 42, names of the measurement modules M1 and M2, and a counter number, and outputs the stored measurement data and the like to the CPU 42.
[0034]
The buffers 23 of the measurement modules M1 and M2 are holding units, and hold the counter numbers input from the communication processing unit 21 to the measuring unit 22.
[0035]
The operation of such an apparatus will be described.
First, the operation of the main module 40 will be described.
The counter 41 increments the counter number at a predetermined interval. The predetermined interval is set to a short interval among the measurement intervals ΔTm1 and Δtm2 set in the measurement modules M1 and M2 at the longest. For example, the predetermined interval is set to about (measurement interval) to (measurement interval) / 2.
[0036]
A timing generation unit (not shown) generates a timing for the measurement module M1 every measurement interval ΔTm1, and a timing for the measurement module M2 occurs every measurement interval ΔTm2. At each timing, the main module 40 causes the measurement module M1 to , Add a counter number to the measurement start command and output it to M2.
[0037]
That is, the CPU 42 of the main module 40 outputs a measurement start command to the communication processing unit 43 at the measurement interval ΔTm1 with the measurement module M1 as a transmission destination. At this time, the communication processing unit 43 acquires the counter number from the counter 41, adds the counter number to the measurement start command, converts it into serial data, and transmits it to the measurement module M1.
[0038]
Further, the CPU 42 of the main module 40 outputs a measurement start command to the communication processing unit 43 at the measurement interval ΔTm2 with the measurement module M2 as a transmission destination. At this time, the communication processing unit 43 acquires a counter number from the counter 41, adds the counter number to the measurement open command, converts it into serial data, and transmits it to the measurement module M2.
[0039]
On the other hand, the operation of the measurement modules M1 and M2 will be described.
The communication processing unit 21 of the measurement modules M1 and M2 extracts a measurement start command and a counter number from the received serial data, and outputs them to the measurement unit 22. Then, the measurement unit 22 stores and holds the counter number in the buffer 23 and measures according to this command. For example, digital data that is measurement data is acquired by an AD converter (not shown) of the measurement unit 22. When this measurement is completed, the measurement unit 22 adds the counter number held in the buffer 23 to the measured measurement data and outputs it to the communication processing unit 21. Further, the communication processing unit 21 converts the measurement data to which the counter number is added into serial data and transmits it to the main module 40. That is, the counter number added to the measurement start command is added to the measurement data measured according to the measurement start command, and is output to the main module 40.
The operation of the main module 40 will be described again.
When the communication processing unit 43 receives serial data from the measurement modules M1 and M2, the measurement data and the counter number are extracted from the received serial data, and the names of the measurement modules M1 and M2 that have transmitted the measurement data and measurement data are displayed. A set is stored in the memory 44 in the order received. Of course, when the measurement intervals ΔTm1 and ΔTm2 elapse, similarly, a measurement start command with a counter number added is transmitted to the measurement modules M1 and M2, and measurement data with a counter number added from the measurement modules M1 and M2 is received. Repeat the operation.
[0041]
When the measurement data for a predetermined number of times is collected, the CPU 42 reads the measurement data, the names of the measurement modules M1 and M2, and the counter number from the memory 44, and performs data processing. At this time, the measurement data is rearranged in order of time according to the counter number, and data processing is performed in order to achieve time alignment (time synchronization) of the measurement data.
[0042]
Next, specific operations of the main module 40 and the measurement modules M1 and M2 will be described with reference to FIGS. FIG. 2 is a timing chart showing the operation of the apparatus shown in FIG. FIG. 3 shows data stored in the memory 44 (measurement data, measurement modules M1 and M2 that have transmitted the measurement data, and data having a counter number as a set). Here, the counter 41 increments the counter number at an interval that is 1/2 times the shortest measurement interval ΔTm1 of the measurement modules M1 and M2. The increment timing may be performed in synchronization with the measurement interval ΔTm1 (for example, immediately before the communication processing unit 43 transmits a measurement start command).
[0043]
The main module 40 adds the measurement start command and the counter number C5 to the measurement modules M1 and M2 and transmits them with the counter number C5 (S20, S21). In addition, a measurement start command and counter numbers C7 and C9 are added and transmitted to the measurement module M1 at each of the counter numbers C7 and C9 for each measurement interval ΔTm1 (S22 and S23). Then, a measurement start command and a counter number C10 are added and transmitted to the measurement module M2 at the counter number C10 for each measurement interval ΔTm2 (S24).
[0044]
On the other hand, the measurement module M1 performs measurement in accordance with the measurement start command to which the counter number C5 is added, and adds the counter number C5 to the measured measurement data D1 (1) and transmits it to the main module 40 (S30). Similarly, measurement is performed in accordance with the measurement start commands to which the counter numbers C7 and C9 are added, and the counter numbers C7 and C9 are added to the measured measurement data D1 (2) and D1 (3) and transmitted to the main module 40. (S31, S33). Further, the measurement module M2 performs measurement according to the measurement start command to which the counter number C5 is added, adds the counter number C5 to the measured measurement data D2 (1), and transmits it to the main module 40 (S32).
[0045]
The main module 40 receives the measurement data D1 (1), D1 (2), D2 (1), D1 (3) from the measurement modules M1, M2 at the counter numbers C6, C8, C9, C10, respectively (S30 to S30). S33). Then, as shown in FIG. 3, data in which the measurement modules M1, M2 name, counter numbers C5, C7, C9 are paired with the measurement data D1 (1) to D1 (3), D2 (1) in the order received. Store in the memory 44.
[0046]
Further, when the CPU 42 performs data processing from the data set in the memory 44, the measurement data is rearranged in the order of time by the counter numbers C5, C7, and C9, and the data processing is performed with the aim of time alignment (time synchronization). Do. Specifically, the memory 44 stores the measurement data D1 (1), D1 (2), D2 (1), and D1 (3) in this order, but the measurement data is D1 (1), D2 (1 ), D1 (2), and D1 (3). Since the measurement data D1 (1) and D2 (1) have the same counter number C5, the data processing may be performed assuming that the measurement is started at the same time.
[0047]
In this way, the main module 40 adds the counter numbers C5, C7, and C9 to the measurement start command and transmits them to the measurement modules M1 and M2, and the measurement modules M1 and M2 receive the measurement data D1 (1) to D1 (3). , D2 (1) is added with the counter numbers C5, C7, C9 received together with the measurement start command and transmitted to the main module 40, so even if the measurement intervals ΔTm1, ΔTm2 of the measurement modules are different, the measurement starts. Can be determined. Thereby, temporal alignment of measurement data between measurement modules can be ensured.
[0048]
In addition, since the CPU 42 performs data processing by rearranging the measurement data based on the counter numbers C5, C7, and C9 added to the measurement data D1 (1) to D1 (3) and D2 (1), the measurement module Even if the measurement intervals ΔTm1 and ΔTm2 are different, data processing can be performed based on the time when the measurement is started. Thereby, temporal alignment of measurement data between measurement modules can be ensured.
[0049]
In addition, this invention is not limited to this, The following may be sufficient.
(1) Although the counter that increments the counter number at predetermined intervals and outputs the counter number is given as the time output means, a clock that outputs time (for example, a real-time clock) may be used.
[0050]
(2) Although the configuration in which two measurement modules M1 and M2 are provided is shown, any number of measurement modules may be provided.
[0051]
【The invention's effect】
The present invention has the following effects.
The main module adds the time information to the measurement start command and sends it to the measurement module, and the measurement module adds the time information added to the measurement start command to the measurement data and sends it to the main module. Even when the measurement intervals are different, it is possible to determine the time when the measurement is started. Thereby, temporal alignment of measurement data between measurement modules can be ensured.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a timing chart showing an operation example of the apparatus shown in FIG.
FIG. 3 is a diagram showing an example of a set of data stored in a memory 44;
FIG. 4 is a configuration diagram of a conventional multipoint data collection apparatus.
FIG. 5 is a timing chart showing an operation example in a conventional apparatus.
[Explanation of symbols]
10 Internal serial buses 21, 43 Communication processing unit 22, measurement unit 40 Main module 41 Counter 42 CPU
M1, M2 measurement module

Claims (7)

A multi-point data collection device comprising a plurality of measurement modules for measuring according to a measurement start command from a main module and outputting measurement data to the main module, wherein the main module and the plurality of measurement modules are connected by a dedicated bus In
The measurement interval differs between the measurement modules,
The main module adds the time information to the measurement start command based on the measurement interval of each of the measurement modules, and individually designates and outputs the measurement module as the transmission destination.
The measurement module adds time information added to the measurement start command to measurement data measured after receiving the measurement start command, and outputs the measurement data to the main module ,
The multipoint data collection device , wherein the dedicated bus is one serial bus shared by the main module and the plurality of measurement modules . The main module
A time output means for outputting time information;
Adding a time information of the time output means, a communication processing unit for exchanging data with the plurality of measurement modules via the dedicated bus;
The multipoint data collection device according to claim 1, wherein The main module
3. The multipoint data collecting apparatus according to claim 2, further comprising a data processing means for rearranging the measurement data in time order from the time information added to the measurement data. The measurement module
A communication processing unit for exchanging data with the main module via the dedicated bus;
A measurement unit that holds time information from the communication processing unit, performs measurement according to a measurement start command, adds the held time information to the measured measurement data, and outputs the measurement data to the communication processing unit. The multipoint data collection device according to claim 1, wherein the multipoint data collection device is provided.   4. The multipoint data collection apparatus according to claim 2, wherein the time output means of the main module is a counter that increments a count value at a predetermined interval and outputs the count value as time information.   6. The multipoint data collection apparatus according to claim 5, wherein the counter sets the predetermined interval as the measurement interval of the measurement module at the longest.   4. The multipoint data collection device according to claim 2, wherein the time output means of the main module outputs time as time information.

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