JPH0217998B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention has one master station and a plurality of slave stations, and transmits a synchronization word and a plurality of information words between the master station and each slave station. The present invention relates to a remote monitoring and control system that transmits frame transmission information.

[Conventional technology]

Conventionally, this type of remote monitoring and control system has been widely used to monitor and control the status of terminal devices scattered far away in power systems and the like.

FIG. 5 is a block diagram of a conventional system, which is composed of one master station 1 and a plurality of slave stations 2-1 to 2-N. Remote monitoring and control equipment 11-1 to 11-N consisting of a TC) or a cyclic digital information transmission device (CDT) are provided corresponding to the slave stations 2-1 to 2-N, and each slave station 2 -1 to 2-N are provided with remote monitoring and control equipment 20 consisting of a telecontrol device or a cyclic digital information transmission device.

The slave stations 2-1 to 2-N are terminal devices 3 to be monitored.
-1 to 3-N, respectively, and transmits and receives required transmission information using N pairs of transmission lines _L1 to _LN installed between the master station and the master station.

In this case, the remote monitoring and control equipment 11-1 to 11-
The transmission information mutually received by N and 20 is
It is encoded with NRZ code, and one frame is the 6th
As shown in the figure, a synchronization word SW having a specific bit pattern for frame synchronization, and multiple information words DW ₁ each word consisting of 44 bits.
It is composed of ~DW _M. And this one
Frame transmission information is frequency modulated and cyclically transmitted to each slave station. Note that a word address indicating the position within one frame is added to one information word DW, and this word address is used to identify information that should be processed preferentially. .

[Problem that the invention seeks to solve]

However, in this conventional system, two lines are required for each slave station: a line for receiving transmission information (control information) from the master station 1 and a line for sending transmission information (monitoring information) to the master station 1. For this reason, when the number of slave stations increases, the total length of transmission paths laid between the master station and the slave stations becomes extremely large, leading to an increase in transmission costs and maintenance costs.

[Means and actions for solving problems]

The present invention was made to solve the above-mentioned problems.
The present invention provides a remote monitoring and control system that can reduce transmission costs and maintenance costs by providing a relay device that reedits frame transmission information and transmits it to a master station or each slave station.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a relay device 4 is arranged between a master station 1 and N slave stations 2-1 to 2-N, and One frame of transmission information from the master station 2-N to the master station 1 is re-edited by this relay device 4 and transmitted via the transmission path _L0 , and conversely, from the master station 1 to each of the slave stations 2-1 to 2-2. −
One frame of transmission information for N is re-edited by this relay device 4 into one frame of transmission information for each slave station and transmitted to each slave station 2-1 to 2-N.

FIG. 2 shows the relay device 4 re-editing one frame of transmission information received from the master station 1 and transmitting it to the slave stations 2-1 to 2-2.
This figure shows how the relay device 4 receives one frame of transmission information consisting of a synchronization word SW and information words DW ₁ to _{DW 8} from the master station 1 as shown in the figure. Information word DW ₁
~Re-edit the word address information contained in DW ₈ . That is, among the information words DW ₁ to DW ₈ , DW ₁ to _{DW 3} are for the slave station 2-1, DW ₄ to _{DW 5} are for the slave station 2-2, and DW ₆ to _{DW 8} are for the slave station 2-1. If it is for the slave station 2-3, the word address contained in the information words DW ₄ to _{DW 8} is the _4th to 8th position in one frame of the information words DW 4 to DW ₈ . They are numbered "4" to "8". However, this word DW ₄ to _{DW 8} for slave stations 2-2 to 2-3
When dividing and sending, the word DW ₄ is in the first position within one frame, so the word address is "1". Also, since DW ₅ is in the second position, the word address is "2". Similarly, since the information words DW ₆ to DW ₈ sent to the slave station 2-3 are located in the first to third positions, respectively, the word addresses are "1" to "3". Therefore, the relay device 4 transmits such information words DW ₁ to _{DW 8} to the master station 1.
, the word addresses of information words DW ₄ to _{DW 8} to be sent to slave stations 2-2 to 2-3 are re-edited as above, and a synchronization word SW is added to make one frame of transmission information. Split, slave station 2-2
-Transmit to 2-3.

On the other hand, when transmitting the transmission information received from the slave stations 2-1 to 2-N to the master station 1, completely opposite frame conversion processing is performed.

FIG. 3 shows the situation when the relay device 4 re-edits one frame of transmission information received from each slave station 2-1 to 2-3 and transmits it to the master station 1.
-1 receives one frame of transmission information having information words DW ₁ to _{DW 3} from slave station 2-2 to 2-3.
When one frame of transmission information having information words DW ₁ , DW ₂ , DW ₁ to _{DW 3} respectively is received from
Re-edit the word addresses of information words DW ₁ and DW ₂ of slave station 2-2 to "4" and "5", and further edit the word addresses of information words DW ₁ to DW ₃ of slave station 2-3 to "6". to "8" and recombined into one frame of transmission information starting with the information words DW ₁ to DW ₃ of the slave station 2-1 and transmitted to the master station 1.

In this way, the master station 1 and the plurality of slave stations 2-1 to 2-
By providing a relay device between N and N, a hierarchical remote monitoring and control system as shown in FIG. 4 can be constructed. In other words, if a plurality of slave stations A to P that are located close to each other are grouped and a relay device Z is arranged for each group, the transmission path between master station 1 and slave stations A to P can be The length is significantly shorter than that of conventional systems. This can significantly reduce transmission costs and maintenance costs.

Note that when using a hierarchical transmission format like this, as the number of slave stations increases, the frame length of the transmission information transmitted from the relay device to the master station increases, resulting in a delay in the response from the master station to the slave stations. This is a concern. Therefore, if a priority processing function is added to the relay device that detects this state change information only when the state of the terminal device changes and transmits this information preferentially to the master station, the response from the master station can be improved. Monitoring result information of terminal devices can be effectively transmitted without worrying about delays.

Although the transmission information is assumed to be frequency-modulated and transmitted, it may be transmitted as is, or it may be modulated using another modulation method and transmitted.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, since a relay device is provided between a master station and a plurality of slave stations to transmit information, the length of the transmission path laid between the master station and the slave stations is This has the excellent effect of significantly shortening transmission costs and reducing maintenance costs, resulting in an extremely economical configuration. Particularly, when the system is configured in a hierarchical structure, extremely remarkable effects can be obtained.

Furthermore, according to the present invention, since the relay is performed while maintaining the format structure of transmission information, it is possible to provide versatility in the processing at the slave station and the master station, and the data of each part can be Effects such as compatibility can also be obtained when monitoring.

[Brief explanation of drawings]

FIG. 1 is an overall block diagram showing one embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining the frame conversion function of a relay device, and FIG. 4 is a system configuration showing an application example of the present invention. 5 is a diagram showing the configuration of a conventional system, and FIG. 6 is a diagram showing the transmission information format of one frame in the conventional system. 1...Master station, 2-1~2-N...Slave station, 3-1~3
-N...terminal equipment, 4...relay device, _L1 to _LN , _L0 ...
transmission line.

Claims (1)

[Claims] 1. A master station and a plurality of slave stations, and between the master station and the plurality of slave stations, a synchronization word and a plurality of information to which word address information is added, respectively. In a remote monitoring system that transmits transmission information in a predetermined format structure including words, a plurality of transmission information in a predetermined format structure is input from the plurality of slave stations, and word address information of a plurality of information words included in the transmission information is input. and assembles the transmission information of a predetermined format structure from the plurality of slave stations into one transmission information of the same format structure and transmits it to the parent device, and also assembles the transmission information of the predetermined format structure from the parent device into one transmission information of the predetermined format structure. By inputting information and re-editing the word address information of the plurality of information words included in this transmission information, one of the predetermined format structures from the parent device
A relay device that divides one transmission information into a plurality of transmission information for a plurality of slave stations having the same format structure and transmits the divided information to the plurality of slave stations is connected to a transmission path between the master station and the plurality of slave stations. A remote monitoring system characterized by the following: