JPH0259663B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] This invention relates to a reception control method for guaranteeing received messages in a redundant reception system, particularly a reception control method for guaranteeing received messages that prevents the occurrence of synchronization deviation between the working system and the protection system. , Based on the idea of using an external clock for synchronization between the working system and the backup system, the system is designed to prevent messages from being dropped or duplicated even if there is a discrepancy in the reception sequence numbers, and the system is designed to synchronize the working system and the backup system. This is a reception control method for guaranteeing received messages in a duplex receiving system, in which received messages are duplex received using a receiving device for use in duplication, and synchronization is performed between a working receiving device and a backup receiving device. , reception time setting processing element 322, reception file storage processing element 3
23, and a communication processing section 32 having a transmission processing section 324, an external storage section 36, a synchronization processing section 35, and a software clock section 34, and the backup reception device 25 has a reception time setting processing element 422, a reception file Storage processing element 423 and reception processing element 42
A communication processing section 42, an external storage section 46, a message erasure processing section 45, and a software clock section 44 are provided. Time information is supplied from the external clock 23, and in the reception time setting processing elements 322, 422, the software clock devices 34, 44 add the reception time information to the received message, and by associating the time information with the received message. The received message is stored with time information added thereto, and the transmission processing unit 324 in the current receiving device 24
In this way, the message received by the current receiving device is sent to the host system, and the message received by the current receiving device 24 is sent to the host system.
The synchronization processing unit 35 in the standby receiving device 2
The erasure information including the reception time information of the corresponding message on the active side is transmitted to the message deletion processing unit 45 in 5, and the erasure information including the reception time information of the corresponding message on the active side and the time information associated with the received message on the protection side are transmitted. is used to erase the received message in the external storage section 46 of the backup receiving device 25, thereby preventing the message from being dropped or duplicated when switching between the working receiving device and the backup receiving device. Configure.

[Industrial application field]

The present invention relates to a reception control method for guaranteeing received messages in a duplex reception system, and more particularly to a reception control method for guaranteeing received messages that prevents synchronization between the working system and the protection system from occurring.

[Prior art and problems to be solved by the invention]

Generally, in terminals using free-run procedures, even if the reception function of the center is down, the terminal operator cannot recognize it.
Even if a terminal operator sends a received message to the center, there is a risk that the center may be down and not receive the sent message. A common method is to use a dual system to receive messages in duplicate, and if the active system goes down, the remaining backup system continues to receive free-run messages sent from terminals. There is.

A conventional duplex receiving system for telegrams is shown in FIG. In the system shown in FIG. 1, telegrams sent from the terminal 11 are simultaneously received by the working and standby receiving devices 13 and 14 via the shunt 12. Working system and backup receiving device 13, 1
4 are each composed of a communication control unit (CCU) and a communication processing unit (CPU).
The received message is temporarily stored in the reception file (RF) in the communication processing unit (CPU) of the active system and the standby system. Further, during normal operation, the message received in the active system is transferred to the host system 15 and stored in the message file (TF). When the transfer is completed, the host system 15 transfers the
A reception notification is sent to the CPU, which causes the
At the same time as the received message is deleted in the CPU, a deletion notification is sent to the standby CPU. The message received by the protection system is sent to the host system 15, and is deleted by the deletion notification from the active system.

The general format of free-run messages is the second one.
As shown in the figure. The first “ZCZC” is SOM (Start
of Message), and the suffix “NNNN” is
EOM (End of Message). In the system shown in Fig. 1, the reception serial numbers are synchronized (matched) between the working system and the protection system when the receiving devices 13 and 14 start up.
In order to achieve this, in subsequent processing, the active system and standby system are synchronized using the reception sequence number. Furthermore, when recovering from a single-system system failure, the normal system notifies the received serial number, and the serial numbers are synchronized. Therefore, there must be no discrepancy in reception sequence numbers between the active system and the backup system. Note that the reception serial numbers 001 to 999 are usually used for cycling.

By the way, in the communication control unit CCU,
The pulse waveform of the received telegram signal is sampled (the voltage at the center of the pulse is taken out) and the bits are
Since characters are assembled by recognizing ON/OFF,
Due to differences in sampling, etc., characters may be omitted or incorrect characters may be recognized. Therefore, if such erroneous recognition occurs only in one CCU at the "NNNN" location at the end of the message, the reception serial number will be different between the active system and the backup system. In such a state, if the active receiving device goes down and system switching is performed, there is a risk that messages will be missed or duplicated.

The main object of the present invention is to take into account the problems of the conventional system, and based on the idea of using an external clock for synchronization between the active system and the standby system, it is possible to prevent the transmission of messages even when there is a discrepancy in the received serial numbers. An object of the present invention is to provide a reception control method for guaranteeing received messages in a duplex reception system, which can prevent dropout or duplication of messages.

[Means to solve the problem]

According to the present invention, reception control for guaranteeing received messages in a redundant reception system that receives received messages in duplicate using a working receiving device and a backup receiving device and synchronizes between the working receiving device and the backup receiving device In this method, the current receiving device 24 includes a reception time setting processing element 322 and a reception file storage processing element 3.
23, and a communication processing section 32 having a transmission processing section 324, an external storage section 36, a synchronization processing section 35, and a software clock section 34, the backup reception device 25 has a reception time setting processing element 422, a reception file a communication processing unit 42 having a storage processing element 423 and a reception processing element 424;
It is equipped with an external storage section 46, a message deletion processing section 45, and a software clock section 44, and the time information from the common external clock 23 is transmitted to the software clock sections 34 and 44 in the active receiving device and the backup receiving device. The software clock devices 34 and 44 add reception time information to the received message in the reception time setting processing elements 322 and 422, and add time information to the received message by associating the time information with the received message. The transmission processing unit 324 in the current receiving device 24
In this way, the message received by the current receiving device is sent to the host system, and the message received by the current receiving device 24 is sent to the host system.
The synchronization processing unit 35 in the standby receiving device 2
The erasure information including the reception time information of the corresponding message on the active side is transmitted to the message deletion processing unit 45 in 5, and the erasure information including the reception time information of the corresponding message on the active side and the time information associated with the received message on the protection side are transmitted. is used to erase the received message in the external storage section 46 of the backup receiving device 25, thereby preventing the message from being dropped or duplicated when switching between the working receiving device and the backup receiving device. A reception control method for guaranteeing received messages in a duplex reception system is provided.

〔Example〕

A reception control system for guaranteeing received messages in a duplex reception system as an embodiment of the present invention will be explained below with reference to FIG.

In the system shown in FIG. 3, when a message is input from the free-run terminal 21, the input message is simultaneously received by the active receiving device 24 and the backup receiving device 25 via the shunt 22. Each receiving device 24,
At step 25, the bit pattern data is assembled into characters by the communication control units 31, 41 and transferred to the communication processing units 32, 42.
In the communication processing units 32 and 42, the procedure control sections 321 and 421 add the reception line number of the transferred message, and the reception time setting processing sections 322 and 422 add the reception time to the transferred message.
The reception time setting processing units 322 and 422 read the time from the software clock devices 34 and 44, respectively. The received message to which the reception time has been added is stored in the external storage devices 34, 46 by the received file storage processing units 323, 423.

During normal operation, the active transmission processing unit 324
reads the message from the external storage device 36 and transmits it to the host system 26. On the other hand, the backup transmission processing unit 424 reads the message from the external storage device 46 and sends it to the host system 26 in a pseudo manner. In order to match the software clock devices 34 and 44 of the active receiving device 24 and the backup receiving device 25, the software clock correction processing units 33 and 43 periodically read the time from the common external clock device 23,
The value is set in the software clock devices 34, 44.
After receiving the message from the active receiving device 24, the receiving unit 261 of the host system 26 sends the message to the message file storage processing unit 262. The message file storage processing unit 262 recognizes the destination of the message based on the content of the message, stores it in the external storage device 263, and sends a control message to the reception completion notification processing unit 264. The reception completion notification processing unit 264 notifies the active synchronous processing unit 3 that the message has been successfully received.
Notify 5.

In the synchronization processing unit 35, the reception processing unit 353 receives the control message from the host system 26 and sends it to the active system message deletion processing unit 352. The active system message deletion processing unit 352 searches for the message in the external storage device 36 based on the contents of the control message (reception line number, reception time), performs deletion processing, and sends the control message to the deletion notification processing unit 351. The deletion notification processing unit 351 notifies the backup message deletion processing unit 45 in the backup receiving device 25 of deletion information (reception line number, reception time). The backup system message deletion processing unit 45 searches for the relevant message in the external storage device 46 based on the notification information from the active system, and performs deletion processing.

In the receiving system shown in FIG. 3, when setting the time in the receiving time setting processing units 322 and 422, there is a possibility that a slight time difference may occur between the working system and the backup system. Therefore, the standby message deletion processing unit 45 uses the time obtained by adding a few seconds to the reception time in the notification information as a key time, and erases messages older than the key time in the external storage device 46.

〔Effect of the invention〕

According to the present invention, it is possible to provide a reception control system for guaranteeing received messages that can prevent dropping or duplication of messages when switching between the active system and the backup system in a duplex reception system for free-run messages.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing a redundant reception system using a conventional reception control system for guaranteeing received messages;
This figure shows the format of a received message, and FIG. 3 is a circuit diagram of a redundant reception system using the reception control method for guaranteeing received messages according to the present invention. Explanation of symbols, 11... terminal device, 12... shunt, 13... active system receiving device, 14... protection system receiving device, 15... host system, 21... terminal device, 22... shunt, 23...external clock device,
24... Active receiving device, 25... Backup receiving device, 26... Host system, 261... Receiving unit, 262... Message file storage processing unit, 263
...External storage device, 264...Reception completion notification processing unit, 31...Communication control unit, 32...Communication processing unit, 321...Procedure control unit, 322...
... Reception time setting processing section, 323 ... Reception file storage processing section, 324 ... Transmission processing section, 33 ... Software clock correction processing section, 34 ... Software clock device,
35... Synchronization processing unit, 351... Erasure notification processing unit, 352... Message erasure processing unit, 353...
Reception processing unit, 36...external storage device, 41...communication control unit, 42...communication processing unit, 4
21...procedure control section, 422...reception time setting processing section, 423...reception file storage processing section, 42
4... Transmission processing section, 43... Software clock correction processing section, 45... Telegram erasure processing section, 46... External storage device.

Claims (1)

[Scope of Claims] 1. Reception for guaranteeing received messages in a duplex receiving system, in which a working receiving device and a backup receiving device are used to receive received messages in a duplex manner, and synchronization is performed between the working receiving device and the backup receiving device. The control method is such that the current receiving device 24 controls the reception time setting processing element 32.
2, a communication processing section 32 having a reception file storage processing element 323 and a transmission processing section 324, an external storage section 36, a synchronization processing section 35, and a software clock section 34, a communication processing unit 42 having a setting processing element 422, a reception file storage processing element 423, and a reception processing element 424;
It is equipped with an external storage section 46, a message deletion processing section 45, and a software clock section 44, and the time information from the common external clock 23 is transmitted to the software clock sections 34 and 44 in the active receiving device and the backup receiving device. The software clock devices 34 and 44 add reception time information to the received message in the reception time setting processing elements 322 and 422, and add time information to the received message by associating the time information with the received message. The transmission processing unit 324 in the current receiving device 24
In this way, the message received by the current receiving device is sent to the host system, and the message received by the current receiving device 24 is sent to the host system.
The synchronization processing unit 35 in the standby receiving device 2
The erasure information including the reception time information of the corresponding message on the active side is transmitted to the message deletion processing unit 45 in 5, and the erasure information including the reception time information of the corresponding message on the active side and the time information associated with the received message on the protection side are transmitted. is used to erase the received message in the external storage section 46 of the backup receiving device 25, thereby preventing the message from being dropped or duplicated when switching between the working receiving device and the backup receiving device. A reception control method for guaranteeing received messages in a redundant reception system characterized by the following: