JP2004297668A - Multipoint data collection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a multipoint data collection apparatus for collecting data from a plurality of measuring modules at high speed. <P>SOLUTION: The present invention enhances a multipoint data collection apparatus equipped with a main module for serial communication through a serial bus to the plurality of measuring modules connected to the single serial bus. The main module of the present apparatus includes: a setting part for setting a desired measuring module as a polling destination; a communication processing part for collecting data from the measuring module set as the polling destination by the setting part, by means of polling, holding a history of communication based on communication contents when the data are collected, and reporting the communication contents to the setting part; and a received data storage part for storing data received by the communication processing part, and the communication processing part collects data from the measuring module of which the history of communication is not held by means of polling. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-point data collection device including a main module that performs serial communication via the serial bus to a plurality of measurement modules connected to a single system serial bus. The present invention relates to a multipoint data collection device for collecting data.
[0002]
[Prior art]
When measuring signals of various physical quantities such as voltage, resistance, and temperature, data is collected by assigning functions to each module and performing measurements with a plurality of modules. Even when measuring signals of the same physical quantity, if there are many measurement points, measurement is performed using a plurality of modules having the same function to collect data. A multipoint data collection device is a unit in which these modules are united together by an internal bus, for example, a serial bus (for example, Non-Patent Documents 1 to 3).
[0003]
FIG. 4 is a configuration diagram showing a conventional example of such a multipoint data collection device.
In FIG. 4, an internal serial bus 10 is a single-system serial bus, and is a signal line through which serial data is transmitted. The serial bus 10 transmits serial data according to, for example, the RS485 interface standard.
[0004]
The measurement modules M1 to M3 are modules for performing measurement, have a communication processing unit 11 for the measurement module, and a measurement unit 12, and are connected to the internal serial bus 10. The communication processing unit 11 is connected to the serial bus 10 and transmits and receives serial data. The measurement unit 12 performs measurement by connecting a sensor (not shown), for example, a probe for voltage measurement, a thermocouple for temperature measurement, a resistance temperature detector, or the like. The measurement unit 12 is connected to the communication processing unit 11 and performs measurement, setting of measurement conditions, and the like according to the content of the serial data received by the communication processing unit 11, and completes setting of measured data and measurement conditions. Output to the communication processing unit 11.
[0005]
The main module 20 includes a CPU (Central Processing Unit) 21, a memory 22, and a communication processing unit 23 for the main module, and is connected to the internal serial bus 10. The main module 20 transmits commands such as measurement conditions, measurement start, measurement end, and the like to the measurement modules M1 to M3 via the serial bus 10, and receives and collects measurement data, and controls the entire multipoint data collection device. I do. Further, the main module 20 exchanges data with a personal computer (not shown) provided outside.
[0006]
The CPU 21 is a setting unit that outputs a command to a desired measurement module M1 to M3 and sets a polling destination for receiving data corresponding to the output command. The memory 22 is a reception data storage unit, and stores data received from the measurement modules M1 to M3 by polling.
[0007]
The communication processing unit 23 includes a polling destination storage unit 23a and a transmission / reception unit 23b, and is connected to the internal serial bus 10. The communication processing unit 23 converts the command output from the CPU 21 into serial data, serially communicates with the desired measurement modules M1 to M3 via the internal serial bus 10, and communicates with the CPU 21 when the serial communication is completed. Notify the end. Further, data is collected by polling from a polling destination set by the CPU 21, and the received data is stored in the memory 22.
[0008]
The polling destination storage unit 23a stores the polling destination, that is, the measurement modules M1 to M3 that perform data collection by polling, according to the setting from the CPU 21. The transmission / reception unit 23b transmits a command via the internal serial bus 10 with the measurement modules M1 to M3 according to an instruction from the CPU 21, reads a polling destination from the polling destination storage unit 23a, and receives serial data by polling. Do.
[0009]
Note that the internal serial bus 10 is a single-system serial bus, and the measurement modules M1 to M3 and the main module 20 share one serial bus 10. That is, the measurement modules M1 to M3 and the main module 20 are not connected by independent serial buses. Therefore, the main module 20 cannot communicate with the plurality of measurement modules M1 to M3 simultaneously. For example, if the main module 20 is communicating with the measurement module M1, it communicates with the measurement modules M2 and M3. I can't.
[0010]
The multi-point data collection device has such a configuration because it is very important to reduce the size and to reduce the cost. If a plurality of serial buses are provided, it is necessary to provide a plurality of communication processing units 23 also in the main module 20, so that not only the main module 20 but also the entire device becomes large, the number of parts increases, and the cost increases. Would. In particular, when measuring a high voltage, it is necessary to provide insulation between the measurement modules M1 to M3 and the main module 20 in order to obtain a high withstand voltage. Must be a serial bus.
[0011]
The operation of such a device will be described. As an example, an operation in which the main module 20 causes the measurement modules M1 to M3 to perform measurement and collect measurement data will be described.
The CPU 21 of the main module 20 outputs a measurement start command to the communication processing unit 23 with the measurement module M1 as a transmission destination. Thereby, the transmission / reception means 23b of the communication processing unit 23 converts the command from the CPU 21 into serial data, transmits the serial data to the measurement module M1 of the transmission destination via the internal serial bus 10, and performs serial communication. Note that the serial communication is not connectionless, but transmits serial data to which a CRC (Cyclic Redundancy Check) or a checksum is added, and confirms whether the transmission content has been transmitted to the measurement module M1 without fail. If the transmission fails, retransmit the serial data. Then, when the communication processing unit 23 ends the serial communication with the measurement module M1, it notifies the CPU 21 of the end of the communication.
[0012]
When the transmission of the command to the measurement module M1 is completed, similarly, the CPU 21 instructs the communication processing unit 23 to transmit a command to the measurement module M2, and the communication processing unit 23 communicates with the measurement module M2. When the transmission of the command to the measurement module M2 is completed, the CPU 21 instructs the communication processing unit 23 to transmit a command to the measurement module M3, and the communication processing unit 23 communicates with the measurement module M3.
[0013]
When the transmission of the command to start the measurement to the measurement modules M1 to M3 is completed, the CPU 21 stores the measurement modules M1 to M3 as the polling destination in the polling destination storage unit 23a of the communication processing unit 23, and collects data by polling. 23b. As a result, the transmission / reception unit 23b reads the polling destination from the polling destination storage unit 23a, and performs data collection by polling for the measurement modules M1 to M3 in order.
[0014]
On the other hand, the operation of the measurement modules M1 to M3 will be described.
The communication processing unit 11 of each of the measurement modules M1 to M3 extracts a measurement start command from the received serial data and outputs the command to the measurement unit 12.
[0015]
Then, the measurement unit 12 measures the measurement target according to the measurement start command, and outputs the measured data to the communication processing unit 11. Then, the communication processing units 11 of the measurement modules M1 to M3 add the measurement data to the response to the data collection by the polling PM1 to OM3 from the transmission / reception unit 23b. For example, when the transmitting / receiving unit 23b performs data collection on the measurement module M2 by the polling PM2, the measurement module M2 adds measurement data to a response to the polling PM2.
[0016]
The operation of the main module 20 will be described again. FIG. 5 is a diagram showing operations of the CPU 21 and the communication processing unit 23 of the main module 20. 5, the upper part shows the operation of the communication processing unit 23, and the lower part shows the operation of the CPU 21. The horizontal axis indicates time.
[0017]
The transmission / reception means 23b of the communication processing unit 23 sequentially performs polling PM1, polling PM2, and polling PM3 on the measurement modules M1 to M3. Then, for example, when the transmission / reception unit 23b receives a response to which the measurement data is added from the measurement module M2 in the polling PM2, the data collection by the polling PM1 to PM3 is stopped. Further, the communication processing unit 23 extracts the measurement data from the response received by the transmission / reception unit 23b, stores the measurement data in the memory 22, and notifies the CPU 21 that the measurement data has been received.
[0018]
With this notification, the CPU 21 instructs a signal processing unit (not shown) to perform signal processing of the measurement data. Then, when the signal processing of the signal processing section is completed, it instructs the transmitting / receiving means 23b to restart polling. As a result, the transmission / reception unit 23b reads the polling destination from the polling destination storage unit 23a again, and restarts the polling PM1, the polling PM2, and the polling PM3 in order from the measurement module M1. Then, polling PM1 to PM3 is performed until measurement data is received again from any of the measurement modules M1 to M3 or an error occurs in communication with any of the measurement modules M1 to M3. Note that an error is a case where the communication contents at the time of data collection by the polling PM1 to PM3 do not end the communication in a normal procedure. For example, there is no communication response from the measurement modules M1 to M3 or the communication response. Is a case where the CRC or checksum value added to is abnormal.
[0019]
[Non-patent document 1]
Tetsuya Sato and one other "Data Acquisition Unit DARWIN Series", Yokogawa Technical Report, Yokogawa Electric Corporation, 1996, Vol. 40, No. 3, p. 95-98
[Non-patent document 2]
Kasashima et al., "DARWIN Series Hybrid Recorder DR230 / 240", Yokogawa Technical Report, 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 Report, Yokogawa Electric Corporation, 1998, Vol. 42, No. 3, p. 119-122
[0020]
As described above, since the serial bus 10 is a single system, the transmission / reception means 23b of the communication processing unit 23 does not simultaneously collect data by polling with respect to the measurement modules M1 to M3 at the polling destination set by the CPU 21 but sequentially executes data collection. , Polling PM1 to PM3 to receive data.
[0021]
However, the transmission / reception unit 23b reads the polling destination from the polling destination storage unit 23a and performs polling PM1 to PM3 according to the polling destination. Therefore, even when the data is received from the measurement module M2, the polling PM2 is performed on the measurement module M2 as before the data is received. That is, since the polling PM2 is also performed on the measurement module M2 that has received the data, there is a problem that it takes time to receive data from all the measurement modules M1 to M3.
[0022]
On the other hand, it is also possible to adopt a configuration in which the CPU 21 resets the polling destination in the polling destination storage means 23a every time the transmission / reception unit 23b receives data and notifies the CPU 21. However, if the CPU 21 exchanges data with a personal computer (not shown) or instructs a signal processing unit (not shown) to perform signal processing or the like and is under a high load state, it may take a considerable time to reset the polling destination. Absent.
[0023]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to realize a multipoint data collection device that receives data from a plurality of measurement modules at high speed.
[0024]
[Means for Solving the Problems]
The invention according to claim 1 is
A plurality of measurement modules connected to a single serial bus, a multi-point data collection device including a main module that performs serial communication via the serial bus,
The main module includes:
A setting unit for setting a desired measurement module among the plurality of measurement modules as a polling destination,
A communication processing unit that collects data by polling from the measurement module set as a polling destination by the setting unit, retains a communication history based on the communication content at the time of the data collection, and notifies the setting unit of the communication content;
A reception data storage unit for storing data received by the communication processing unit;
Has,
The communication processing unit performs data collection by polling from a measurement module that does not hold the communication history.
[0025]
The invention according to claim 2 is the invention according to claim 1,
The communication processing unit
Polling destination storage means for storing a polling destination;
A communication history storage unit for storing communication history;
Selecting means for reading a polling destination from the polling destination storage means, reading a communication history from the communication history storage unit, and selecting a measurement module having no communication history from the polling destination;
Transmitting and receiving means for collecting data by polling with the measurement module selected by the selecting means as a polling destination, and storing a communication history based on the communication content at the time of data collection in the communication history storage unit;
Which is characterized by having
[0026]
The invention according to claim 3 is the invention according to claim 2,
The transmitting / receiving means terminates the communication with the polling-destination measurement module by means having a normal content and the data is added to the response from the polling-destination measurement module, or a procedure in which the communication content is normal. In the case where the communication is not completed in the step (c), the communication history is set.
[0027]
The invention according to claim 4 is the invention according to claim 3,
The communication history storage unit,
Error history storage means for storing a measurement module that did not end communication normally;
Reception history storage means for storing a measurement module which has normally completed communication and received data;
Is provided.
[0028]
The invention according to claim 5 is the invention according to claim 4,
The selecting means reads the communication history from at least one of the error history storage means and the reception history storage means.
[0029]
The invention according to claim 6 is the invention according to claim 4 or 5,
The reception data storage unit stores the data received from the measurement module for each of the measurement modules,
The communication processing unit notifies the setting unit when there is a change in the error history storage unit or the reception history unit.
[0030]
The invention according to claim 7 is the invention according to claim 6,
The reception data storage unit is a ring buffer.
[0031]
The invention according to claim 8 is the invention according to claim 6, wherein
The reception data storage unit is provided for each of the measurement modules.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention. Here, the same components as those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.
In FIG. 1, a memory 24 is provided instead of the memory 22, and a communication processing unit 25 is provided instead of the communication processing unit 23. The memory 24 is a reception data storage unit, and is provided for each of the measurement modules M1 to M3, and stores data received from each of the measurement modules M1 to M3 by polling.
[0033]
The communication processing unit 25 includes a polling destination storage unit 25a, an error history storage unit 25b, a reception history storage unit 25c, a mask unit 25d, and a transmission / reception unit 25e, and is connected to the internal serial bus 10. The communication processing unit 25 converts the command output from the CPU 21 into serial data, serially communicates with the desired measurement modules M1 to M3 via the internal serial bus 10, and communicates with the CPU 21 when the serial communication is completed. Notify the end. Further, data is collected by polling at a polling destination set by the CPU 21, the received data is stored in the memory 22, and a notification of reception is sent to the CPU 21.
[0034]
The polling destination storage unit 25a stores the polling destination, that is, the measurement modules M1 to M3 that collect data by polling, according to the setting from the CPU 21. The error history storage unit 25b stores a measurement module in which communication has not been completed normally (for example, when there is no communication response or when an error is determined by a CRC check). The reception history storage unit 25c stores the measurement modules M1 to M3 in which communication has been normally completed and data has been added to the responses from the measurement modules M1 to M3.
[0035]
Here, the error history storage unit 25b and the reception history storage unit 25c are communication history storage units, and the communication contents with the measurement modules M1 to M3 at the polling destination do not end in a normal procedure, or the communication is not performed normally. When the procedure is completed and data is added to the response, the measurement modules M1 to M3 that have performed the communication are stored as a communication history.
[0036]
The masking unit 25d is a selecting unit that reads out the polling destination from the polling destination storage unit 25a, reads out the communication history from the error history storage unit 25b and the reception history storage unit 25c, and has no communication history from the polling destination. M1 to M3 are masked and selected.
[0037]
The transmission / reception unit 25e transmits a command to the measurement modules M1 to M3 via the internal serial bus 10 according to an instruction from the CPU 21, or collects data by polling the measurement modules M1 to M3 selected by masking by the mask unit 25d. Then, the communication history based on the communication contents at the time of data collection is stored in the error history storage unit 25b and the reception history storage unit 25c.
[0038]
The operation of such a device will be described.
As an example, an operation in which the main module 20 causes the measurement modules M1 to M3 to perform measurement and collect measurement data will be described. FIG. 2 is a diagram illustrating an example of the operation of the present apparatus. In FIG. 2, the first row from the top shows the operation of the transmission / reception means 25e, the second row shows the operation of the CPU 21, the third row shows the contents stored in the polling destination storage means 25a, and the fourth row. Indicates the content stored in the error history storage unit 25b, the fifth row indicates the content stored in the reception history storage unit 25c, and the sixth row is masked by the masking unit 25d and selected as a new polling destination. 3 shows the measured modules M1 to M3. The horizontal axis indicates time.
[0039]
The CPU 21 of the main module 20 outputs a measurement start command to the communication processing unit 25 with the measurement module M1 as a transmission destination. As a result, the transmission / reception unit 25e of the communication processing unit 25 converts the command from the CPU 21 into serial data, transmits the serial data to the measurement module M1 of the transmission destination via the internal serial bus 10, and performs serial communication. Note that the serial communication is not connectionless, and transmits serial data to which a CRC and a checksum are added, and confirms whether or not the transmission contents can be reliably transmitted to the measurement module M1. If the transmission fails, retransmit the serial data. Then, when the communication processing unit 25 ends the serial communication with the measurement module M1, it notifies the CPU 21 of the end of the communication.
[0040]
When the transmission of the command to the measurement module M1 is completed, similarly, the CPU 21 instructs the communication processing unit 25 to transmit a command to the measurement module M2, and the communication processing unit 25 communicates with the measurement module M2. When the transmission of the command to the measurement module M2 is completed, the CPU 21 instructs the communication processing unit 25 to transmit a command to the measurement module M3, and the communication processing unit 25 communicates with the measurement module M3.
[0041]
When the transmission of the measurement start command to the measurement modules M1 to M3 is completed, the CPU 21 sets and stores the measurement modules M1 to M3 as the polling destination in the polling destination storage unit 25a of the communication processing unit 25, and collects data by polling. Is started by the transmission / reception means 25e. At this time, the communication processing unit 25 clears the communication history of the error history storage unit 25b and the reception history storage unit 25c.
[0042]
The masking unit 25d reads the polling destination from the polling destination storage unit 25a, reads the communication history from the error history storage unit 25b and the reception history storage unit 25c, and reads the communication history from the polling destination measurement modules M1 to M3. The masking is performed by the measurement modules M1 to M3 having the data, and the measurement modules M1 to M3 having no communication history are selected. In this case, since the error history storage unit 25b and the reception history storage unit 25c have just been cleared, the selected polling destinations are the measurement modules M1 to M3. This masking may be performed at all times, or may be performed immediately before the transmission / reception unit 25e reads data.
[0043]
Then, the transmission / reception unit 25e reads the polling destination selected by the masking unit 25d, and performs data collection by polling for the measurement modules M1 to M3 in order.
[0044]
On the other hand, the operation of the measurement modules M1 to M3 will be described.
The communication processing unit 11 of each of the measurement modules M1 to M3 extracts a measurement start command from the received serial data and outputs the command to the measurement unit 12. According to the measurement start command, the measurement unit 12 measures the object to be measured, and outputs the measured data to the communication processing unit 11.
[0045]
Then, the communication processing units 11 of the measurement modules M1 to M3 add the measurement data to the response to the data collection by polling from the transmission / reception unit 25e of the main module 20, and transmit the response.
[0046]
The operation of the main module 20 will be described again.
The transmission / reception unit 25e of the communication processing unit 25 sequentially performs polling PM1, polling PM2, and polling PM3 on the measurement modules M1 to M3. In the polling PM1 to PM3, if the communication is terminated in a normal procedure and the measurement data is not added to the response from the measurement modules M1 to M3, the error storage unit 25b and the reception history unit 25c are cleared. The polling destination after masking by the masking means 25d remains as it is, as is the measurement modules M1 to M3.
[0047]
Then, when the polling PM1 to PM3 makes a round, the transmission / reception unit 25e reads the polling destination from the masking unit 25d again, and performs the polling PM1 to PM3 in the same manner. Here, if the polling PM1 does not end the communication in the normal procedure, the polling PM2 ends the communication in the normal procedure, and if the measurement data is added to the response from the measurement module M2, After the transmission / reception unit 25e makes a round of the polling PM1 to PM3, the error history storage unit 25b stores the name of the measurement module in which the communication did not end in a normal procedure and an error occurred, that is, the measurement module M1, and communicated to the reception history storage unit 25c. , The name of the measurement module to which the measurement data is added, that is, the measurement module M2. Thereby, the polling destination after the masking by the mask unit 25d is only the measurement module M3.
[0048]
Further, the communication processing unit 25 stores the content of the error in the polling PM1 and the received data in the polling PM2 in the memory 24 corresponding to each of the measurement modules M1 and M2, and notifies the CPU 21 when the polling PM1 to PM3 makes a round. Do. As a result, the CPU 21 instructs a signal processing unit (not shown) to perform signal processing on the measurement data. The contents of the error may be separately stored in the communication processing unit 25 and stored in the communication processing unit 25.
[0049]
Then, the transmission / reception unit 25e stores the communication history after one round of the polling PM1 to PM3, reads the polling destination from the masking unit 25d, and performs only the polling PM3. Further, the polling PM3 is repeated until the communication with the measurement module M3 cannot be completed in a normal procedure or until there is a response from the measurement module M3 to which the measurement data is added. When the CPU 21 confirms the return of the measurement module M1 in which the communication error has occurred, or when the data processing of the received measurement data is completed, the CPU 21 reads the corresponding measurement module from the error history storage unit 25b or the reception history storage unit 25c. M1 and M2 may be cleared, and the polling PM1 to PM3 may be restarted by the transmission / reception means 25e.
[0050]
As described above, the masking unit 25d reads the polling destination measurement modules M1 to M3 from the polling destination storage unit 25a, and the measurement modules M1 to M3 from which communication has not been completed in a normal procedure from the error history storage unit 25b. The communication is completed from the reception history storage unit 25c in a normal procedure, and the response from the measurement modules M1 to M3 is read out from the measurement modules M1 to M3 to which the measurement data is added, and masking is performed. The polling PM1 to PM3 is performed only for the measurement modules M1 to M3 for which the measurement data has not been added to the response. Thus, polling can be performed efficiently. Therefore, data can be received at high speed from the plurality of measurement modules M1 to M3.
[0051]
Further, a memory 24 is provided for each of the measurement modules M1 to M3, and errors and received data from each of the measurement modules M1 to M3 are stored in the respective memories 24 and notified to the CPU 21 after one round of polling, so that communication is normal. It is necessary to stop the data collection by the polling PM1 to PM3 every time the procedure ends and the measurement data is added to the response from the measurement modules M1 to M3 or the communication does not end normally. There is no. That is, in the case of the apparatus shown in FIG. 4, the data collection by the polling PM1 to PM3 is stopped every time data is received from any of the measurement modules M1 to M3, and the CPU 21 does not process the data. The data collected from the next measurement modules M1 to M3 may destroy previously collected data. However, since the memory 24 is provided for each of the measurement modules M1 to M3, it is possible to receive data from another measurement module M1 to M3 while performing data processing, thereby increasing the efficiency of data processing. it can. That is, data can be received at high speed from a plurality of measurement modules. Further, the load on the CPU 21 can be reduced, and the CPU 21 can prioritize other processes.
[0052]
The present invention is not limited to this, and may be as follows.
(1) When polling PM1 to PM3 to the polling destination selected by the masking unit 25d makes a round, the transmitting / receiving unit 25e stores the measurement modules M1 to M3 in which communication has failed in the error history storage unit 25b, the measurement modules M1 to M3. Although the configuration has been described in which the measurement modules M1 to M3 added with the measurement data to the response from the storage unit 25c are stored in the reception history storage unit 25c, each time such communication content occurs, the communication history of the measurement modules M1 to M3 is stored. The configuration may be such that the error history is stored in the error history storage unit 25b and the reception history storage unit 25c.
[0053]
That is, the transmission / reception means 25e operates as shown in FIG. The same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. The operation is substantially the same as the operation shown in FIG. 2 except that if the communication is not completed in a normal procedure in the polling PM1, the transmission / reception means 25e causes the error history storage means 25b to execute the measurement in which an error occurs in the error history storage means 25b at the same time as the completion of the polling PM1. The module name, that is, the measurement module M1 is stored. If the communication is completed in the normal procedure in the polling PM2 and the measurement data is added to the response from the measurement module M2, the transmission / reception unit 25e receives the data in the reception history storage unit 25c simultaneously with the end of the polling PM2. The measurement module name, that is, the measurement module PM2 is stored.
[0054]
Of course, the mask unit 25d selects the measurement modules M2 and M3 as the polling destination after the measurement module M1 is stored in the error history storage unit 25b, and performs polling after the measurement module M2 is stored in the reception history storage unit 25c. First, only the measurement module M3 is selected. The notification to the CPU 21 may be made each time the communication does not end in a normal procedure or every time the communication ends in a normal procedure and the measurement data is added to the response from the measurement module M2.
[0055]
(2) Although the configuration in which the memory 24 is provided for each of the measurement modules M1 to M3 has been shown, a memory having a large capacity is used continuously, and the end of the continuous memory is allocated to the leading end of the memory to form a ring. And a ring buffer having no apparent termination may be used.
[0056]
(3) The mask unit 25d reads out the measurement modules M1 to M3 in which an error has occurred from the error history storage unit 25b and the measurement modules M1 to M3 that have received data from the reception history storage unit 25c, and selects a polling destination. However, a configuration may be employed in which either one of the reception history storage unit 25b and the reception history storage unit 25c is read and the selection is performed.
[0057]
(4) The configuration in which the main module 20 transmits a measurement start command to the measurement modules M1 to M3 and collects measurement data by polling has been described. However, measurement conditions (for example, range setting of the measurement unit 12, A polling may be performed by transmitting a command such as a sampling interval, and data indicating that the setting of the measurement conditions has been completed from the measurement unit 12 may be collected. That is, the present invention can be applied to a configuration in which the data transmitted by the polling PM1 to PM3 from the measurement modules M1 to M3 in response to the command transmitted by the main module 20.
[0058]
(5) In the apparatus shown in FIG. 1, the configuration in which the number of the measurement modules M1 to M3 is three has been described, but a desired number of the measurement modules M1 to M3 may be provided.
[0059]
【The invention's effect】
According to the present invention, the following effects can be obtained.
According to the first to eighth aspects, the communication processing unit performs data collection by polling to the polling destination set by the setting unit, and retains a communication history based on the communication content at the time of collection. Then, since the communication processing unit polls the measurement module that does not hold the communication history, the polling can be efficiently performed. Therefore, data can be received at high speed from a plurality of measurement modules.
[0060]
According to claims 6 to 8, the received data storage unit stores the received data in a different place for each measurement module, so that every time data is received, data collection by polling is stopped and the received data is stored. There is no need to perform the processing of That is, data can be received at high speed from a plurality of measurement modules. Further, since the setting unit can process the received data in parallel with the data reception without being affected by the communication state, the load on the setting unit can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing one embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of an operation in the device shown in FIG.
FIG. 3 is a diagram for explaining another example of the operation in the device shown in FIG. 1;
FIG. 4 is a configuration diagram of a conventional multipoint data collection device.
FIG. 5 is a diagram illustrating an example of an operation in a conventional multipoint data collection device.
[Explanation of symbols]
10 Internal serial bus
20 Main module
21 CPU
24 memory
25 Communication processing unit
25a Polling destination storage means
25b Error history storage means
25c reception history storage means
25d mask means
25e transmission / reception means
M1 to M3 measurement module

Claims (8)

A plurality of measurement modules connected to a single serial bus, a multi-point data collection device including a main module that performs serial communication via the serial bus,
The main module includes:
A setting unit for setting a desired measurement module among the plurality of measurement modules as a polling destination,
A communication processing unit that collects data by polling from the measurement module set as a polling destination by the setting unit, retains a communication history based on the communication content at the time of the data collection, and notifies the setting unit of the communication content;
A reception data storage unit for storing data received by the communication processing unit,
The multipoint data collection device, wherein the communication processing unit performs data collection by polling from a measurement module that does not hold the communication history. The communication processing unit
Polling destination storage means for storing a polling destination;
A communication history storage unit for storing communication history;
Selecting means for reading a polling destination from the polling destination storage means, reading a communication history from the communication history storage unit, and selecting a measurement module having no communication history from the polling destination;
A transmission / reception unit for collecting data by polling with the measurement module selected by the selection unit as a polling destination, and storing a communication history based on the communication content at the time of the data collection in the communication history storage unit. Item 4. The multipoint data collection device according to Item 1. The transmitting / receiving means terminates the communication with the polling-destination measurement module by means having a normal communication content, and the data is added to the response from the polling-destination measurement module, or when the communication content is normal. 3. The multi-point data collection device according to claim 2, wherein the communication history is set when the communication is not ended in step (1). The communication history storage unit,
Error history storage means for storing a measurement module that did not end communication normally;
4. The multipoint data collection device according to claim 3, further comprising a reception history storage unit that stores a measurement module that has normally completed communication and received data. 5. The multipoint data collection device according to claim 4, wherein the selection unit reads a communication history from at least one of the error history storage unit and the reception history storage unit. The reception data storage unit stores the data received from the measurement module for each of the measurement modules,
The multipoint data collection device according to claim 4, wherein the communication processing unit notifies the setting unit when the error history storage unit or the reception history unit changes. The multipoint data collection device according to claim 6, wherein the reception data storage unit is a ring buffer. The multipoint data collection device according to claim 6, wherein the reception data storage unit is provided for each of the measurement modules.

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