JP2007249759A - Monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system wherein a communication load does not increase even if the number of monitors increases, capable of performing monitoring without increasing a PLC load. <P>SOLUTION: One of the plurality of monitors 10, 20, 30, e.g. the monitor (the main monitor) 10 provided from the beginning periodically performs requirement 1, 2 of data to a PLC 40 by a polling method, receives response data 1', 2' from the PLC 40, converts them into engineering values, and displays them. The extended other monitors (the sub-monitors) 20, 30 capture all pieces of data of network information, take in only transmission data (the response data) 1', 2' of the PLC 40, and perform processing. Thereby, only the data requirement for the display only from the monitor 10 is needed, the data requirement for the display from the monitors 20, 30 is not needed to reduce the loads of the PLC 40 and a network 100. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a monitoring system for monitoring a plant such as a water and sewage system.

  A recent small monitoring system uses a monitoring device that uses monitoring package software in a personal computer and a programmable controller (hereinafter referred to as PLC) that performs control.

  Communication between the monitoring device using a personal computer and the PLC often uses a communication method possessed by each PLC. This communication is a so-called polling method in which a data request is transmitted from a monitoring device using a personal computer, and the received PLC returns a response.

  That is, the monitoring device periodically requests data from the PLC, and the PLC that has received the request creates response data and transmits the response data to the monitoring device. The monitoring device that has received the response data converts the received data into an engineering value and displays it.

  If the number of monitoring devices is increased, the demand for data increases, so the load on the PLC becomes heavy and there is no room for other processing times. Since each monitoring device basically has the same display items, the same data request for display is transmitted to each monitoring device.

  When the number of facilities to be monitored increases, it is necessary to install a plurality of monitoring devices. However, in the polling communication, if the number of monitoring devices is increased, the data request for the PLC increases, so the load on the PLC becomes heavy and normal control is affected. For this reason, normally only about 2 units can be installed.

Therefore, in order to reduce the load on the PLC when a plurality of monitoring devices are connected to one PLC, a display relay device is provided between the plurality of monitoring devices and the PLC. Patent Document 1 discloses that the load on the PLC is reduced by organizing and overlapping the overlapping data requests from the monitoring devices and making a data request to the PLC.
JP 2000-242326 A

  As described above, in the conventional monitoring system, there is a problem that the load on the PLC becomes heavy because the number of monitoring devices increases and the data request for the PLC increases.

  Also, as disclosed in Patent Document 1, it is possible to reduce the load on the PLC by providing a display relay device between a plurality of monitoring devices and the PLC. In this case, however, a new display relay device is provided. There is a problem that the system configuration becomes complicated and the cost increases.

  The present invention has been made in order to solve the conventional problems as described above. A monitoring device that mainly communicates with a PLC is provided, and other monitoring devices capture (capture) communication data on the network. Accordingly, it is an object of the present invention to provide a monitoring system that does not require a display relay device, does not increase the communication load even if the number of monitoring devices increases, and can perform monitoring without increasing the PLC load.

  In order to achieve the above object, the present invention provides a monitoring system that displays and monitors data from a programmable controller by a plurality of monitoring devices, and requests data from a predetermined monitoring device of the plurality of monitoring devices to the programmable controller. The data transmitted from the programmable controller in response to this request is captured by each of a plurality of monitoring devices, and is captured and displayed.

  According to the present invention, even if the number of monitoring devices increases, the communication load does not increase, and monitoring can be performed without increasing the PLC load.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following drawings, the same symbols indicate the same or corresponding parts.

(First embodiment)
FIG. 1 shows the configuration of the monitoring system according to the first embodiment of the present invention.

  As shown in the figure, for example, a sewage treatment system PLC 40 is connected to a network 100 such as a LAN, and a plurality of monitoring devices 10, 20, 30 for monitoring the sewage treatment system are connected to the network 100. Has been. The network 100 is also connected to other PLCs 50 and 60.

  The plurality of monitoring devices 10, 20, and 30 are monitoring devices that use monitoring package software in a personal computer. In this embodiment, one of the plurality of monitoring devices 10, 20, and 30 is provided from the beginning, for example. The monitoring device (main monitoring device) 10 periodically sends data requests 1 and 2 to the PLC 40 in a polling manner, receives the response data 1 'and 2' from the PLC 40, converts them into engineering values, and displays them. However, the other added monitoring devices (sub-monitoring devices) 20 and 30 capture all data of the network information, capture only the transmission data (response data) 1 ′ and 2 ′ of the PLC 40, and perform processing. Configured to do.

  Each of the monitoring devices 10, 20, 30 includes display processing units 11, 21, 31, signal processing units 12, 22, 32, transmission / reception processing units 13, 23, 33, control units 14, 24, 34, and a RAM. Etc., storage units 15, 25, and 35, respectively. Further, the PLC 40 includes a transmission / reception processing unit 41.

  Next, the operation of this embodiment will be described in detail.

  In the monitoring device 10, the data request 1 is performed from the transmission / reception processing unit 13 to the PLC 40 by the polling function of the control unit 14. This data request 1 is made by broadcast using the PLC 40 as the primary destination and the monitoring devices 20 and 30 as the secondary destinations. Upon receiving the data request 1, the transmission / reception processing unit 41 of the PLC 40 creates response data 1 ′ and transmits it to the monitoring device 10. The response data 1 ′ is transmitted by broadcast with the main destination as the monitoring device 10 and the secondary destinations as the monitoring devices 20 and 30. The monitoring apparatus 10 receives the response data 1 ′ at the transmission / reception processing unit 13, writes the response data 1 ′ into the storage unit 15 at the control unit 14, reads the data from the storage unit 15 and passes the data to the signal processing unit 12, Convert to engineering values. Thereafter, the display processing unit 11 displays the data.

  The transmission / reception processing unit 23 of the added monitoring device 20 captures (captures) all the data on the network 100 to which the monitoring device 20 is a broadcast destination, that is, the data request 1 and the response data 1 ′. Only the transmission data, i.e., response data 1 'is taken in and processed. That is, after the response data 1 ′ is written in the storage unit 25 by the control unit 24, the data is read from the storage unit 25 and passed to the signal processing unit 22 to be converted into engineering values. Thereafter, the display processing unit 21 displays the data. In the added monitoring device 30, the same processing as that of the monitoring device 20 is performed.

  After a predetermined period, the data request 2 is made from the monitoring device 10 to the PLC 40 and the response data 2 ′ is returned from the PLC 40. These processes are performed in the same manner as in the case of the data request 1 and the response data 1 ′. Is called.

  As described above, according to this embodiment, since the display items of the monitoring devices 20 and 30 are basically the same as those of the monitoring device 10, it is only necessary to make a data request for display from the monitoring device 10. Data requests for display from the monitoring devices 20 and 30 are not necessary, and the load on the PLC 40 and the network 100 can be reduced.

(Second Embodiment)
Next, a monitoring system according to the second embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the display items are the same in the monitoring device 10 and the monitoring devices 20 and 30. Basically, the same data is displayed by the monitoring device in order to monitor the entire data in the monitoring of the plant, but the monitoring device may be divided for each facility (each system). Therefore, in the case of this second embodiment, the data to be monitored in common is requested by the above method, and only the data for each equipment (each system) is individually requested, thereby reducing the overall load. . An operation request or the like is issued from each monitoring device, but since the issue frequency is low, there is no problem even if it is output individually.

  As shown in FIG. 2, the configuration of the second embodiment is such that, for example, two PLCs 140 and 150 are used as a sewage treatment system PLC, and two PLCs 240 and 250 are used as a sludge treatment system PLC. 100. The monitoring device (main monitoring device) 110 and the monitoring device (sub monitoring device) 120 are used as monitoring devices for monitoring the sewage treatment system, and the monitoring device (main monitoring device) is used as the monitoring device for monitoring the sludge treatment system. Device) 210 and monitoring device (sub-monitoring device) 220 are connected to the network 100, respectively. Furthermore, a monitoring device 310 is connected to the network 100 as a monitoring device that monitors the entire processing plant.

  Although not shown, each of the monitoring devices 110, 120, 210, 220, and 310 is similar to each monitoring device of the first embodiment, and includes a display processing unit, a signal processing unit, a transmission / reception processing unit, and a control unit. And a storage unit such as a RAM. Each of PLCs 140, 150, 240, and 250 includes a transmission / reception processing unit.

  The sewage treatment system monitoring device (main monitoring device) 110 periodically requests data from the sewage treatment system PLC 140 and PLC 150 by a polling method, and the sewage treatment system PLC 140 and PLC 150 of its own system. All the transmission data (response data) from is captured and stored, and processing for display is performed, and all data of the network information is captured and transmitted from PLC 240 and PLC 250 of the sludge treatment system which is another system Of the data (response data), data common to both systems is captured and stored, and processing for display is performed. Further, the sewage treatment system monitoring device (sub-monitoring device) 120 captures all data of the network information and transmits all of the transmission data (response data) from the PLC 140 and the PLC 150 of the sewage treatment system that is its own system. Then, the data common to both systems among the transmission data (response data) from the PLC 240 and the PLC 250 of the sludge treatment system, which is another system, is stored and processed for display.

  On the other hand, the sludge treatment system monitoring device (main monitoring device) 210 periodically requests data to the sludge treatment system PLC 240 and PLC 250 by a polling method, and the sludge treatment system PLC 240 is its own system. All the transmission data (response data) from PLC 250 is captured and stored, and processing for display is performed, and all data of network information is captured, from PLC 140 and PLC 150 of the sewage treatment system which is another system Of these transmission data (response data), data common to both systems is also captured and stored, and processing for display is performed. Further, the sludge treatment system monitoring device (sub-monitoring device) 220 captures all data of the network information, and transmits all of the transmission data (response data) from the sludge treatment system PLC 240 and PLC 250 of its own system. The data common to both systems among the transmission data (response data) from the PLC 140 and the PLC 150 of the sewage treatment system, which is another system, is stored and processed for display.

  Furthermore, the monitoring device 220 that monitors the entire treatment plant captures all data of the network information, transmits all of the transmission data (response data) from the PLC 140 and the PLC 150 of the sewage treatment system, and the PLC 240 of the sludge treatment system. All of the transmission data (response data) from the PLC 250 is captured and stored, and processing for display is performed.

  Next, the operation of this embodiment will be described more specifically.

  For example, when a data request regarding the amount of inflow of sewage is made to the PLC 140 from the transmission / reception processing unit of the monitoring device (main monitoring device) 110 of the sewage treatment system, the main request is the PLC 140 and the sub-destination is the other destination. The monitoring devices 120, 210, 220, and 310 are performed in the same broadcast.

  The transmission / reception processing unit of the PLC 140 that has received the data request creates response data of the inflow amount of sewage and transmits it to the monitoring device 110. This response data is broadcast by using the monitoring device 110 as the primary destination and the monitoring devices 120, 210, 220, and 310 as the secondary destination. Also, if the response data of the inflow of sewage is not common to both systems (that is, it must be displayed on the monitoring system for the sewage treatment system and the monitoring system for the entire treatment plant, If it is data that does not need to be displayed by the monitoring device of the sludge treatment system that is the system of the system, the flag of the sewage treatment system that is its own system is set and transmitted in the response data.

  The response data of the inflow amount of sewage transmitted from the PLC 140 is received by the transmission / reception processing units of the monitoring device 110 that is the main destination and the monitoring devices 120, 210, 220, and 310 that are the secondary destinations. Since the monitoring device 120 has its own system flag set in the response data, it is captured and stored, and processing for display is performed. Also, the monitoring device 310 captures data of both systems. However, the monitoring device 210 and the monitoring device 220 are discarded without being captured because the other system flag is set in the response data.

  Next, when a data request regarding the amount of generated sludge is made to the PLC 150 from the transmission / reception processing unit of the monitoring device (main monitoring device) 110 of the sewage treatment system, the main request is the PLC 150 and the secondary destination is the secondary destination. The other monitoring devices 120, 210, 220, and 310 are broadcast.

  The transmission / reception processing unit of the PLC 150 that has received the data request creates response data of the amount of generated sludge and transmits it to the monitoring device 110. This response data is broadcast by using the monitoring device 110 as the primary destination and the monitoring devices 120, 210, 220, and 310 as the secondary destination. Moreover, if the response data of the amount of sludge generated is common to both systems (that is, not only the monitoring system for the sewage treatment system and the monitoring system for the entire treatment plant, but also other systems) If it is the data that needs to be displayed even in the monitoring device of the sludge treatment system), the response data is sent with a flag indicating that it is common data.

  The response data of the generated amount of sludge transmitted from the PLC 150 is received by the transmission / reception processing units of the monitoring device 110 that is the main destination and the monitoring devices 120, 210, 220, and 310 that are the secondary destinations. In 110, 120, 210, 220, and 310, since a flag indicating that the data is common is set, processing for capturing and displaying is performed.

  In addition, when a data request regarding the sludge concentration is made to the PLC 240 from the transmission / reception processing unit of the sludge treatment system monitoring device (main monitoring device) 210, the data destination is the PLC 240 as the main destination and the other destination is the other destination. The monitoring devices 110, 120, 220, and 310 are performed in the same broadcast.

  The transmission / reception processing unit of the PLC 240 that has received the data request creates response data on the sludge concentration and transmits it to the monitoring device 210. This response data is sent by broadcast with the primary destination as the monitoring device 210 and the secondary destinations as the monitoring devices 110, 120, 220, and 310. Also, if the response data of the sludge concentration is not common to both systems (that is, it must be displayed on the monitoring system for the sludge treatment system and the monitoring system for the entire treatment plant, If it is data that does not need to be displayed by the monitoring device of the sewage treatment system that is the system of the system, the flag of the sludge treatment system that is its own system is set and transmitted in the response data.

  The sludge concentration response data transmitted from the PLC 240 is received by the transmission / reception processing units of the monitoring device 210 that is the main destination and the monitoring devices 110, 120, 220, and 310 that are the secondary destinations. Since the monitoring device 220 has its own system flag set in the response data, it is captured and stored and processed for display. The monitoring device 310 also captures data of both systems, and captures it. However, the monitoring device 110 and the monitoring device 120 are discarded without being captured because the other system flag is set in the response data.

  As described above, according to this embodiment, monitoring of both systems out of response data from the PLC in response to a data request from the main monitoring device of one of the sewage treatment system and the sludge treatment system. Data that needs to be displayed on the device, that is, data that is common to both systems, captures response data in all monitoring devices by setting a flag indicating that it is common data in the response data, and monitors its own system Response data is captured by the monitoring device of the own system (and the monitoring device of the entire processing plant) by setting the flag of the own system for data that needs to be displayed only by the device (and the monitoring device of the entire processing plant). By doing so, the overall load can be reduced.

(Third embodiment)
Next, a monitoring system according to the third embodiment of the present invention will be described.

  In the third embodiment, the monitoring device (sub-monitoring device) 20 of the first embodiment is provided with a soundness check unit that diagnoses the soundness of the monitoring device (main monitoring device) 10. FIG. 3 shows the configuration of the monitoring device 20 in this case. In the figure, reference numeral 26 denotes a soundness check unit.

  In the configuration of the first embodiment, when the monitoring device 10 stops, other monitoring devices 20 cannot monitor. For this reason, in the third embodiment, when the monitoring device 20 receiving the monitoring data cannot receive the data, the monitoring device 20 determines that the monitoring device 10 is stopped, and the monitoring device 20 starts transmitting / receiving data. To do. When the monitoring device 10 returns to normal, when the request data from the monitoring device 10 is transmitted, the monitoring device 20 receives the data and determines that the monitoring device 10 has returned, and stops transmission.

  Next, the operation of this embodiment will be described more specifically.

  As described in the first embodiment, the monitoring apparatus 10 periodically makes data requests 1, 2,... To the PLC 40 by the polling function, and the PLC that has received the data requests 1, 2,. 1 ′, 2 ′,... Are transmitted. Since the monitoring device 20 is a destination of the broadcast of these data requests 1 and 2 and response data 1 ′, 2 ′,..., The transmission / reception processing unit 23 of the monitoring device 20 transmits these data requests 1 and 2. , ... and response data 1 ', 2', ... can be captured.

  Therefore, in the third embodiment, the data requests 1, 2,... And the response data 1 ′, 2 ′,. Data requests 1, 2,... And response data 1 ′, 2 ′,.

  The control unit 24 reads the response data 1 ′, 2 ′,... From the storage unit 25, passes the data to the signal processing unit 22, converts it into an engineering value, and displays the data on the display processing unit 21. However, in the third embodiment, data transmitted from the monitoring device 10 is written in the storage unit 25 via the control unit 24 by the soundness check unit 26. It is diagnosed whether the monitoring apparatus 10 is normal by periodically scanning and checking the requests 1, 2,.

  For example, when the monitoring apparatus 10 makes a data request about 10 times per second by the polling method, the soundness check unit 26 checks the data request written in the storage unit 25 every second. If the data request from the monitoring device 10 is not detected as a result of the check, the data request from the monitoring device 10 is re-checked after 1 second and checked again after 1 second. If not detected, it is determined that the monitoring device 10 has stopped transmitting the data request, and the monitoring device 20 becomes the main monitoring device instead of the monitoring device 10 and starts a data request to the PLC 40 by the polling method. . Thereafter, the soundness check unit 26 continues to check the data request written in the storage unit 25 every second, and when the data request from the monitoring device 10 is detected, the monitoring device 10 is in a normal state. It judges that it returned, and stops transmission of the data request from the monitoring apparatus 20.

  The monitoring device 30 is also provided with a soundness check unit for diagnosing soundness. When both the monitoring device 10 and the monitoring device 20 stop transmitting data requests, the monitoring device 30 becomes the main monitoring device, and polling is performed. A data request to the PLC 40 may be started by a method.

  Furthermore, after the monitoring device 10 stops transmitting the data request and the monitoring device 20 starts transmitting the data request as the main monitoring device on behalf of the monitoring device 10, the monitoring device 10 returns to a normal state. Even in this case, the monitoring device 10 detects that the data request is transmitted from the monitoring device 20, and the monitoring device 10 does not resume the transmission of the data request, and the monitoring device 20 directly serves as the main monitoring device for data to the PLC 40. The request transmission may be continued.

  In addition, the monitoring device 10, the monitoring device 20, and the monitoring device 30 are all provided with the soundness check unit as described above, and the order of becoming the main monitoring device (the order of becoming the main monitoring device first, and the main monitoring). When the monitoring device that is the device stops transmitting the data request, the order in which the monitoring device becomes the next main monitoring device) is determined in advance, and the monitoring device that is the main monitoring device transmits the data request. It can also be implemented in such a way that when it stops, the determined monitoring device becomes the main monitoring device in sequence.

  According to this embodiment, a highly reliable system can be realized.

The block diagram which shows the structure of the monitoring system which concerns on the 1st Embodiment of this invention. The block diagram which shows the structure of the monitoring system which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the principal part of the monitoring system which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

10, 20, 30 ... monitoring devices 11, 21, 31 ... display processing units 12, 22, 32 ... signal processing units 13, 23, 33 ... transmission / reception processing units 14, 24, 34 ... control units 15, 25, 35 ... storage Part 26 ... Soundness check part 40 ... PLC
41: Transmission / reception processing unit.

100 ... Network 110, 120, 210, 220, 310 ... Monitoring device 140, 150, 240, 250 ... PLC

Claims (4)

  In a monitoring system in which data from a programmable controller is displayed and monitored by a plurality of monitoring devices, data is requested from the predetermined monitoring device of the plurality of monitoring devices to the programmable controller, and the request is transmitted from the programmable controller. A monitoring system characterized in that data is captured by each of a plurality of monitoring devices, captured and displayed.   In a monitoring system composed of a plurality of systems each including a monitoring device for displaying and monitoring data from the programmable controller, data is requested from a predetermined monitoring device of each system to the programmable controller in each system. The data transmitted from the programmable controller in response to this request must be displayed on the monitoring system of its own system, or displayed on the monitoring system of its own system and other systems. Discriminating information for discriminating whether the data is necessary common data, each system monitoring device captures data transmitted from its own system and the programmable controller of another system, respectively, the discriminating information Data and common data that need to be displayed on your own monitoring device. Interrupt, the monitoring system being characterized in that so as to display.   3. The monitoring system according to claim 2, further comprising a monitoring device that monitors the whole, and the monitoring device that monitors the whole captures, captures, and displays all data transmitted from the programmable controllers of each system. A monitoring system characterized by doing so. In a monitoring system in which data from a programmable controller is displayed and monitored by a plurality of monitoring devices, data is periodically requested from the predetermined first monitoring device among the plurality of monitoring devices to the programmable controller, and this request is met The data transmitted from the programmable controller is captured by each of the plurality of monitoring devices, captured, displayed, and the data request of the first monitoring device is normal in the second monitoring device other than the first monitoring device. When the data request of the first monitoring device is not normally performed, the second monitoring device periodically requests data from the programmable controller. A monitoring system characterized by that.

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