JPH06169322A - System for reducing packet transmission load - Google Patents

Abstract

PURPOSE:To collect CDT data that had the state changes and to transmits these data in a single packet. CONSTITUTION:The state change detecting parts 221-2212 are provided against a transmitter part for detecting the state changes of the CDT data received from the CDT data transmitting parts 121-1212. A packet assembling part 24c turns the data that has the state changes into a packet. When the state changes of the CDT data are detected by the parts 221-2212, the part 24c assembles those data that had the state changes into a packet and inputs it to the transmitter side 26. Thereafter the data on the state changes caused before the transmission end information is received from the side 26 are turned into a queue. Then the CDT data turned into a queue are collected and turned into a single packet for transmission after the transmission end information is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention packetizes status data periodically sent from a plurality of transmitters at predetermined time intervals and transmits it to a higher-level device, and immediately packetizes data whose status has changed. The present invention relates to a packet transmission load reduction method when a status change frequently occurs in a data collection system that transmits to a host device.

[0002]

_2. Description of the Related Art As shown in FIG. 5, an electric power company or the like establishes a data collection system 1 ₁ , 1 ₂ , 1 ₃ ... for each area, and periodically visits all power stations and substations in the area. Data sent (on / off of various switches, on / off of various lines)
(OFF, power consumption, etc.) is collected and transmitted to the central center via the packet network 2, and the center executes predetermined processing such as centralized monitoring of each substation and power consumption monitoring. There is. That is, the data collection systems 1 ₁ , 1 ₂
.. are data transmission units 4 ₁₁ of each substation with multiple lines,
4 ₁₂ ... Data coming in from 4 _ms (CDT data:
Cyclic Data Transmission data) and collect the CDT
Data is assembled into a packet and transmitted to the center (host computer) 3 via the packet network 2, and the host computer performs centralized monitoring of each substation and power consumption monitoring. The CDT data is treated as important data among the data processed by the host computer 3, and based on this CDT data, the host computer 3
Performs various controls and detects abnormalities.

The data collection system 1 ₁ , 1 _2, ... Is a CD
There are the following two conditions for the timing of assembling T data into a packet and transmitting it. One is a fixed cycle of CDT
This is a case where data is assembled into a packet and transmitted, and the other case is a case where when the on / off data of the CDT data has a state change (state change), it is immediately assembled into a packet and transmitted. That is, normally, the data collection system assembles the CDT data received from each line into a packet at a fixed cycle and transmits it to the host computer. However, when there is an abnormality or the like, the data is immediately packetized and is transmitted to the host computer. Then, the host computer executes a predetermined process according to the situation.

[0004] Figure 6 is a block diagram of a data collection system 1 _1, 4 _{11-4 112} a CDT data transmission unit. In the data collection system, 1a _{1 to} 1a ₁₂ are Cs provided corresponding to the CDT data transmission units (lines) 4 ₁₁ to 4 _112.
DT data receiving unit, 1b each CDT data transmission unit 4 ₁₁ -
4 ₁₁₂ is a data buffer provided with storage areas (# 1 to # 12) corresponding to 4 ₁₁₂ , and each CDT data transmission unit 4 ₁₁ to 4 _112.
It stores the CDT data that is sent periodically from the. 1
Reference numeral c is a state change detection unit that detects the state change (called state change) by checking the contents of the data buffer 1b, and 1d is a packet assembling unit, which assembles and outputs CDT data into packets at a fixed cycle and outputs the CDT data. When there is a state change (state change), the changed data is immediately assembled in a packet and output. Reference numeral 1e is a transmission unit that automatically performs the HDLC transmission procedure, 1f is a driver, and 1g is a main processing unit that adds the destination and type of the packet and sends the packet to the packet network.

As shown in FIG. 7, the CDT data is composed of 63 words, one word consists of 44 bits, and the latter 22 bits are inverted data of the first 22 bits.
It has a duplication structure. The word number is designated by 6 bits out of 22 bits, and various data is designated by 16 bits. The bit position in each 16-bit word is assigned a meaning, such as generator on / off, radio on / off, 1/2 generator on / off, various sensors on / off, etc. The status of each part and power consumption can be notified. Each CDT data transmission unit 4 ₁₁ -
4 ₁₁₂ periodically send CDT data shown in FIG. 7 to the data collection system 1 _1, CDT receiver 1a ₁ to 1A ₁₂ writes the received data in the corresponding storage area of the data buffer 1b. The state change detection unit 1c sequentially checks the state of the data buffer 1b from the beginning, and when the state change is detected, requests the packet assembling unit 1d to assemble. The packet assembling unit 1d immediately assembles only the CDT data that has changed into a packet, requests the transmitting unit 1e to transmit the packet, and transmits the packet to the host computer 3 via the driver 1f and the main processing unit 1g.

For example, as shown in FIG. 8, the fourth part of the data received from the CDT data transmitters 4 ₁₁ , 4 ₁₂ , 4 ₁₃ and 4 _{14 is} received.
When a state change occurs in the word, the sixth word, the seventh word, and the ninth word, the state change detection unit 1c requests the packet assembling unit 1d to assemble a packet each time, and the packet assembling unit assembles a packet of the state change data. Then, the transmitting unit 1e is requested to perform the transmission and the transmission is performed. That is, FIG.
Then, when the state change is detected four times, the packet is assembled four times and the packet is transmitted four times.

[0007]

As described above, in the conventional data collecting system, the state change data is monitored by the state change detection section, and every time the state change data is detected, the packet assembly section is requested to assemble and transmitted. It is configured to do. For this reason, if the CDT data is frequently changed, the load on the packet assembling unit and the load on the transmitting unit will rapidly increase, and most of the CPU processing in the data collection system will be used for these two processings. You may have to wait, or if you neglect and lose CDT data,
Alternatively, there is a problem in that the transmission process and the assembling process are delayed and a delay occurs. From the above, it is an object of the present invention to reduce the load on the packet assembling unit and the transmitting unit to eliminate the loss of the CDT data by collectively transmitting the packetized CDT data by packetizing them and transmitting the data. It is an object of the present invention to provide a packet transmission load reduction method when a status change frequently occurs in a data collection system in which an assembly process is not delayed and a delay does not occur.

[0008]

FIG. 1 is a diagram for explaining the principle of the present invention. 11 is a data collection system, 12 ₁ , 12 ₂ ,
・ ・ ・ 12 ₁₂ is installed in the substation etc., and regularly CDT
It is a CDT data transmission unit that transmits data to the data collection system 11. In the data collection system, 21 ₁
To 21 ₁₂ CDT data receiver for receiving CDT data, 22 ₁ to 22 ₁₂ state change detector for detecting a content change in the CDT data received (state change), 23 each CDT data transmission unit 12 ₁ to 12 Storage area corresponding to ₁₂ (# 1 to # 1
2), a data buffer for storing regularly sent CDT data, 24a is a queuing unit for forming a queue of CDT data that has undergone a state change, and 24c is a case where a state change queue exists. Is a packet assembling unit for collectively packetizing all the CDT data forming the queue, and 26 is a packet transmitting side for sending packets to the packet network.

[0009]

When the state change detectors 22 _{1 to} 22 ₁₂ detect a state change, the packet assembling unit 24 c assembles the CDT data having the changed state into a packet and inputs it to the transmitting side.
After that, the state change data that has occurred until the transmission completion notification is received from the transmission side 26 is queued (queued), and after the transmission completion notification is received, the queued CDT data is collected. It is assembled into one packet and transmitted. As described above, since the CDT data that has been changed is collectively packetized and transmitted, the load on the packet assembling unit and the transmitting unit can be reduced, loss of the CDT data can be eliminated, and the transmission process and the assembling process can be performed. There is no waiting.

[0010]

【Example】Overall configuration FIG. 2 is a block diagram of an embodiment of the present invention. In the figure, 11 is a day
Data collection system, 12 ₁, 12₂・ ・ ・ 12₁₂Is a substation
It is installed in a place, etc., and regularly collects CDT data.
It is a CDT data transmission unit for transmitting to the system 11. Day
21 in the data collection system 11₁~ 21₁₂Is CDT
A CDT data receiving unit for receiving data, 22₁~ 22₁₂
Is a state change detector for detecting a state change of the received CDT data,
23 is each CDT data transmission unit 12₁~ 12₁₂In response to
It has a storage area (# 1 to # 12) and is sent regularly.
Data buffer for storing CDT data, 24 is
Create a queue of the existing CDT data and collect these
The state change processing unit for packetizing and outputting the packet, 25 is regularly
CDT data stored in the data buffer 23
The fixed-cycle processing unit for packetizing and outputting the
Is the packet sender that sends the packet to the packet network.

As shown in FIG. 3, the state change processing section 24 stores a state change queuing section 24a for creating a queue of state-changed CDT data, and a queue for state-changed CDT data. State change queue storage unit 24b and queue C
A packet assembling unit 24c for assembling DT data into a single packet, and a transmitting unit 2 for automatically performing an HDLC transmission procedure in response to a transmission request from the packet assembling unit.
4d and a completion notifying unit 24e for receiving a transmission completion notification from the transmitting side 26 and notifying the packet assembling unit 24c.

The fixed cycle processing section 25 includes a packet assembling section 25a for assembling the CDT data in the data buffer 23 into packets at a constant cycle, and a transmitting section 25b for automatically performing the HDLC transmission procedure in response to a transmission request from the packet assembling section. , A completion notifying unit 25 which receives a transmission completion notification from the transmitting side 26 and notifies the packet assembling unit 25a.
have c. The transmitting side 26 includes a driver 26a and a main processing unit 26b which adds a destination and a type of a packet to a packet network and sends the packet to the state change processing unit 24 and the fixed cycle processing unit 25 via the driver. Have

Overall operation The CDT data periodically transmitted from the respective CDT data transmitters 12 ₁ , 12 ₂ , ... 12 ₁₂ are lines L _{1 to} L _12.
Is received by the CDT data receiving unit 21 ₁ to 21 ₁₂ corresponding via, it is written in the corresponding storage # 1 to # 12 of the respective data buffer 23. The CDT data of the previous cycle is rewritten with the CDT data of the current cycle. When no change occurs in each CDT data, the packet assembling unit 25a of the fixed cycle processing unit 25 packetizes all the CDT data stored in the data buffer 23 at regular time intervals and requests the transmitting unit 25b to transmit the packetized data. Then, the transmitting unit sends it to the packet network via the driver 26a and the main processing unit 26b, and transmits it to the host computer.
When the transmission is completed, the main processing unit 26b sends a transmission completion notification to the fixed cycle processing unit 25 via the driver 26a. Upon receipt of the transmission completion notification, the completion notification unit 25c of the fixed cycle processing unit notifies the packet assembling unit 25a. After that,
Similarly, the fixed cycle processing unit 25 packetizes all the CDT data stored in the data buffer 23 at regular time intervals and transmits the packetized data to the host computer.

In parallel with the above, the state change detectors 22 _{1 to} 22 ₁₂
Checks whether the CDT data received by the corresponding CDT data receiving units 21 _{1 to} 21 ₁₂ has a change,
When the state change is detected, the state change processing unit 24 is notified. In order to know which line of the CDT data has changed in the notified information, the state change queuing unit 24a connects the line identification data to the head of the queue based on this information and stores it in the state change queue storage unit 24b. Remember. Packet assembly unit 2
4c constantly checks whether or not a queue (queue) exists in the state change queue storage unit 24b.
The line-specific data constituting the above is removed from the queue, and the CDT data in the storage area of the data buffer 23 designated by the line-specific data is packetized. Then, the packet assembling unit 24c requests the transmitting unit 24d to transmit the packet, and the transmitting unit transmits the driver 26a and the main processing unit 26.
It is sent to the packet network via b and the state change data is transmitted to the host computer. When the main processing unit 26b completes the transmission, the main processing unit 26b sends a transmission completion notification to the state change processing unit 24 via the driver 26a. When the completion notifying unit 24e of the state change processing unit 24 receives the transmission completion notification, the packet assembling unit 2
Notify 4c.

During this time, if a state change occurs on another line or another word, it is detected by the state change detection units 22 _{1 to} 22 ₁₂ and notified to the state change queuing unit 24 a to notify the state change. The queuing unit sequentially connects the line identification data to the queue. When the packet assembling unit 24c receives the transmission completion notification, the packet assembling unit 24c queues in the state change queue storage unit 24b.
Exists, and if there is, a data buffer 2 designated by all the line-specific data forming the queue.
The CDT data in 3 is assembled into one packet, and all line specific data is dequeued. Thereafter, similarly, the packet assembling unit 24c requests the transmitting unit 24d to transmit the packet, and the transmitting unit sends the packet to the packet network through the driver 26a and the main processing unit 26b. Do it until it runs out. During this period, the fixed cycle processing unit 25 packetizes the data and transmits the data at regular intervals as described above.

Concrete Example In FIG. 4, a state change occurs at the fourth word of the first line, and then the second line.
Data flow when a change occurs in the fifth line of the line, the ninth word of the fourth line, and the sixth word of the third line (see
Kens). First, the state change detector 22 ₁ detects the state change of the fourth line of the first line, and the state change processing unit 24 is notified of the state change. Packet assembling unit 2 of state change processing unit 24
4c packetizes the CDT data of all the first lines and requests the transmission unit 24d to transmit the data. When transmission is performed from the transmission unit 24d via the driver 26a, the driver notifies the transmission completion. Completion notification unit 24e of the state change processing unit 24
Notifies the packet assembling unit 24c when it detects the completion of transmission. Second line fifth word generated during the above - de th ninth word fourth line - de th third line sixth word - each state change detection unit 22 is de-th state change _2, 22 _4, It is detected by 22 ₃ and is notified to the state change processing unit 24 to be queued.

The packet assembling unit 24c checks whether or not the queue exists by the transmission completion notification. In this case, all the CDT data of the second line, all the CDT data of the third line, and all of the fourth line are present. The CDT data of 1 is assembled into one packet, and a transmission request is made to the transmission unit 24d.
When transmission is performed from the transmission unit 24d via the driver 26a, a completion notice is sent from the driver. The packet assembling unit 24c checks whether or not the queue exists by the transmission completion notification, and if the queue does not exist, waits until the queue is generated due to the state change.

As described above, by dividing the processing into the state change processing section 24 and the fixed cycle processing section 25, it is possible to prevent the state change processing from interfering with the transmission processing of the fixed cycle data.
In addition, the state change detectors 22 _{1 to} 22 ₁₂ are connected to the CDT data receiver 2
By providing every 1 _{1 to} 21 ₁₂ , it is possible to notify the state change for each line. Therefore, the packets assembled by the packet assembling unit 24c of the state change processing unit 24 can be bundled and transmitted on a line-by-line basis. Therefore, the number of packets transmitted by the transmitting unit 24d and the driver 26a is reduced and an increase in load is suppressed. be able to. Similarly, the number of packets to be assembled can be reduced and an increase in load can be suppressed by performing the assembly for each line and for all the status change data until the transmission completion notification comes. Although the present invention has been described above with reference to the embodiments, the present invention can be variously modified according to the gist of the present invention described in the claims, and the present invention does not exclude these.

[0019]

As described above, according to the present invention, the state change detecting section for detecting the state change of the received data is provided corresponding to the transmitting device (line), and the packet assembling section for packetizing the data having the state change is provided. When a state change is detected by the state change detector, the packet assembler assembles the state-changed data into a packet and inputs it to the sending side, and thereafter occurs until the sending side receives a transmission completion notification. Since the state change data is configured to be assembled and transmitted in one packet, the CDT data that has undergone the condition change can be packetized and transmitted even if the condition changes frequently. Can reduce the load of
Therefore, the loss of the CDT data can be eliminated, and the reliability of the data collection system can be improved without waiting for the transmission process and the assembling process.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a configuration diagram of a state change processing unit.

FIG. 4 is an explanatory diagram of a data flow of the present invention.

FIG. 5 is an overall configuration diagram of a CDT data communication system.

FIG. 6 is a configuration diagram of a conventional data collection system.

FIG. 7 is a configuration diagram of CDT data.

FIG. 8 is an explanatory diagram of a conventional CDT data state with frequent occurrence.

[Explanation of symbols]

11 ... Data collection system 12 ₁ , 12 ₂ , ... 12 ₁₂ ... CDT data transmitter 21 _{1 to} 21 ₁₂ ... CDT data receiver 22 _{1 to} 22 ₁₂ ... Condition change detector 23 ... Data buffer 24a .. Queuing unit 24c .. Packet assembling unit 26 .. Packet transmitting side

Claims (1)

[Claims] 1. Status data sent periodically from a plurality of transmitters is packetized at predetermined time intervals and transmitted to a higher-level device, and data whose status has changed is immediately packetized and transmitted to a higher-level device. In the packet transmission load reduction method when the status change frequently occurs in the data collection system, the status change detection unit that detects the status change of the received data is provided corresponding to the transmission device, and the packet assembly unit that packetizes the changed data is provided. When a state change is detected by the state change detector, the packet assembler assembles the data with the changed state into a packet and inputs it to the transmission side, and then occurs until the transmission completion notification is received from the transmission side. A packet transmission load reduction method characterized in that the changed state data is assembled into a packet and transmitted.