JPH08272708A - Data transmission equipment - Google Patents

Abstract

PURPOSE: To eliminate transmission line switching operation at the time of occurrence of transmission line fault and improve the reliability by connecting doubled transmission lines to a control station which has plural data transmission control parts and equipping the control station with specific dual-port memories. CONSTITUTION: The doubled transmission lines 600 and 700 are connected to transmission controllers (data transmission control part) 113 and 114 of a remote data input/output controller (control station), and transmission controllers 221 and 222, 331 and 332, and 441 and 442 of process input/output devices (slave station) 200-400 are provided corresponding to the doubled transmission lines 600 and 700. And, the dual-port memories 116 and 117 are provided which correspond to the transmission controllers 113 and 114 of the control station, one to one. Therefore, the processor 111 of the control station can update data by using the two dual-port memories 116 and 117 at all times. Consequently, the transmission lines need not be switched in spite of a single fault occurring in a process input/output device and the reliability of received data is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device in which one management station and a plurality of slave stations are connected by a duplicated transmission line.

[0002]

2. Description of the Related Art FIG. 5 shows a block diagram of a conventional data transmission apparatus having a redundant transmission line configuration. An example is shown in which one remote data input / output control device 1 which is a management station and three process input / output devices 2, 3 and 4 which are slave stations are connected.

The remote data input / output device 1 comprises a processor 11, a main memory 12, transmission controllers 13 and 14 which are data transmission control units, and a switching circuit 15. The process input / output devices 2 to 4 are also provided with transmission controllers 21, 22, 31, 32, 41, 42 that perform transmission control.

Taking a power plant as an example, the remote data input / output device 1 is installed in a central control room, and the process input / output devices 2 to 4 are installed in a place apart from the central control room. The process input / output devices 2 to 4 mainly input process data from a detector (not shown) in a plant and transmit the process data to the remote data input / output device 1. The remote data input / output device 1 mainly transmits an operation command to a plant device (not shown) to the process input / output devices 2-4. The process input / output devices 2 to 4 output the sent operation command to the plant equipment. Upon receiving the broadcast transmission command from the remote data input / output device 1, the process input / output devices 2 to 4 transmit data to the remote data input / output device 1 in a predetermined order. In the case of power plants, the transmission cycle is 100 ms.

Now, the case where the processor 11 uses the switching circuit 15 to select the transmission controller 13 and performs data transmission with the process input / output devices 2 to 4 through the transmission line 6 will be described.

First, the processor 11 is a transmission controller.
21 is selected to perform transmission with the process input / output device 2.
That is, the processor 11 uses the main memory as a transmission operation.
The transmission data is read from 12 and transmitted to the transmission controller 21 via the transmission controller 13 and the transmission path 6.

Further, as a receiving operation, the processor 11 transmits the data to the transmission controller 13 via the transmission path 6 and the transmission controller 6.
Issue a data send command to 21. The transmission controller 21 receives it, and the transmission path 6 and the transmission controller 13
It is stored in the main memory 12 as data from the process input / output device 2 via.

Similarly, the process input / output devices 3,
The data is transmitted to and from No. 4, and these are periodically repeated to update the data. Here, consider the behavior when a failure occurs in the transmission system. The processor 11 determines that there is an abnormality in data transmission using the transmission controller 13 based on a check bit added to the received data, and switches the switching circuit 15 to select the transmission controller 14. After that, the transmission line 7 and the transmission controllers 22, 32, 42 are used to continue the data transmission, prevent the system from being down due to a single failure of the transmission system, and improve the operation rate.

[0009]

[Problems to be Solved by the Invention]

(1) Since one line of the transmission line is stopped due to duplication (cold standby state), initialization processing such as connection establishment at the time of switching when a failure occurs in the used system requires switching, so switching is required The time becomes longer, and the continuity of control cannot be maintained, leading to performance degradation.

(2) In applications where reliability is required, such as power needs, duplexing of transmission lines is indispensable, but in the conventional single system stop mode, for example, in FIG. 6, the transmission controllers 21 and 32 are In the case of a failure, the remote data input / output control device 1 is replaced by the process input / output device 2
It becomes possible to input data from and 3 at the same time. That is, the remote data input / output control device 1 is usually 100
Data is input from process input / output devices 2 and 3 during ms, and processing is performed, but since transmission controllers 22 and 31 are used, switching cannot be performed within 100 ms, and data inconsistency is lost. , Reliability decreases.

An object of the present invention is to realize a highly reliable remote data input / output control device which improves the performance by eliminating the transmission line switching operation which is necessary when a fault occurs in the transmission line.

[0012]

In order to achieve the above object, in claim 1, one management station having two data transmission control units and two data transmission control units of the management station are provided. In a data transmission device having a duplexed transmission line connected by a plurality of slave stations having two data transmission control units provided corresponding to the duplexed transmission line, the management station is the Provided is a data transmission device characterized in that a data transmission control unit of a management station is equipped with a 1: 1 compatible dual port memory.

According to another aspect of the present invention, the management station uses only an operation mode in which normal data is selected from data in two dual-port memories and used, and data in one of the dual-port memories is used. The data transmission apparatus according to claim 1, further comprising an operation mode.

According to a third aspect of the present invention, the management station is set to an operation mode in which only data in the other dual port memory is used when a plurality of abnormalities in the data in one dual port memory are continuously detected. The data transmission device according to claim 1, wherein the data transmission device is provided.

According to another aspect of the present invention, when the management station detects an abnormality in the data of a specific slave station in one of the dual port memories, it operates in an operation mode in which only the data in the other dual port memory is used. The data transmission device according to claim 1, wherein the data transmission device is provided.

According to a fifth aspect of the present invention, the management station uses the dual port memory as a backup of the main memory, thereby providing the data transmission apparatus according to the first aspect.

[0017]

In the device configured as described in claim 1,
Instead of the switching circuit for selecting the data transmission control unit, a dual port memory corresponding to the data transmission transmission control unit and 1: 1 for updating the data of the data transmission control unit (a memory accessible from both the processor and the transmission controller) ) Is provided.

According to another aspect of the present invention, the management station selects an operation mode in which normal data is selected from the data in the two dual port memories and uses it. And an operation mode that uses only the data described above to enable high-speed processing.

In the apparatus constructed as described in claim 3, when the management station detects a plurality of abnormalities in the data in one of the dual port memories in succession, only the data in the other dual port memory is detected. By using
Enables high speed processing.

In the apparatus constructed as described in claim 4, when an abnormality is detected in the data of a specific slave station in one of the dual port memories, the management station only uses the data in the other dual port memory. To ensure that important data entered by a particular slave station is not missed.

In the apparatus constructed as described in claim 5, the management station responds to the abnormality of the main memory by using the dual port memory as a backup of the main memory.

[0022]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a block diagram of an embodiment. One remote data input / output control device that is a management station
100 and three process input / output devices 200, 30 that are slave stations
An example is shown where 0 and 400 are connected.

The remote data input / output device 100 includes a processor 111, a main memory 112, transmission controllers 113 and 114 which are data transmission control units, and a dual port memory.
It is composed of 116 and 117.

The process input / output devices 200, 300, 400 include transmission controllers 221, 222, 33 for controlling transmission.
1, 332, 441, 442 are provided. Processor 11
1 activates the transmission controllers 113 and 114 simultaneously.
Now, transmission with the process input / output device 200 will be described.

As a transmission operation, the processor 111 reads transmission data from the main memory 112 and transfers it to the dual port memories 116 and 117. This can be realized by changing the addresses of the dual port memory 116 and the dual port memory 117. Then the transmission controller
113 transmits data to the transmission controller 221 via the transmission line 600, and at the same time, the transmission controller 114 transmits data to the transmission controller 222 via the transmission line 700. On the side of the process input / output device 200, either of the transmission controllers 221 and 222 normally used data is used.

In the case of the receiving operation, the management station 100 selects the transmission controller 221 via the transmission controller 113 and the transmission path 600, and at the same time selects the transmission controller 222 via the transmission controller 114 and the transmission path 700. The received data from the process input / output device 200 is stored in the dual port memories 116 and 117.

FIG. 2 shows an example of a data storage format in the dual port memories 116 and 117. The dual port memories 116 and 117 store the data of the process input / output devices 200, 300 and 400 in the same format. After this, the processor 111 operates the dual port memories 116 and 117.
Data received normally (determined by the status etc. in the stored data) is extracted, and the main memory 11
Transfer to 2 and use as received data.

For example, in the case of FIG. 3, a dual port memory
Since the data in the process I / O device 300 out of the data in 116 is abnormal, the processor 111 determines that the data from the process I / O device 300 is the dual port memory 11
Extract the data in 7. Any other data is used as the other data.

According to this embodiment, since the processor 111 can always update the data by using the two dual port memories 116 and 117, the transmission line can be switched by a single failure of the process input / output device. It becomes unnecessary, the processing time accompanying the switching operation is eliminated, and the performance is improved, and at the same time, the reliability of the received data is improved by the normal data extraction processing.

The data extraction process in the processor 111 is effective for improving the reliability of the received data. On the other hand, especially when many process input / output devices are connected, the time required for the data extraction process of the processor 111 is long. There are many drawbacks.

Therefore, as another embodiment, when a plurality of abnormalities continue in the data in the dual port memory 116 as in the case of FIG. 4, for example (two consecutive abnormalities in FIG. 4). It is judged that the transmission control unit (the transmission controller 113, the dual port memory 116, etc.) in the remote data input / output control device is not the failure of the process input / output device alone, and only the dual port memory 117 is used. This enables the processor 11 shown above.
The data extraction process in 1 is unnecessary and high-speed processing is possible. It should be noted that the switching to the mode using only one of the dual port memories can be performed when the remote data input / output control device is preferentially operated in addition to the above-described failure occurrence.

According to this embodiment, since the data update with the continuous process input / output device is disabled during the data update using the transmission lines 600 and 700, the use of the data from the corresponding transmission line is prevented. High-speed processing becomes possible by stopping and switching to a mode in which only data from the other transmission line is used.

As another embodiment, as a means for detecting a failure of a single-sided transmission line in a mode in which only one of the dual port memories is used, a plurality of data in the above dual port memory is abnormal. In addition to the above, the process input / output devices 200 and 30 are devices that are indispensable for maintaining the control function of the remote data input / output control device 100.
Either 0 or 400 is specified in advance, and when the data in the dual port memory from the relevant process I / O device becomes abnormal, the use of the transmission path of that dual port memory system is stopped and the other system is stopped. Means for switching to only use may be provided. For example, the process input / output device 20
If the data from 0 is important, the process I / O device 200 data in the dual port memory 116 has become abnormal, regardless of whether the data of other process I / O devices is normal or abnormal. Switch to using 117.

According to this embodiment, during the data update using the transmission lines 600 and 700, the use of the data from the corresponding transmission line is stopped and the other transmission line is stopped due to the abnormality of the process input / output device designated in advance. High-speed processing is possible by switching to the mode in which only the data from is used.

As another embodiment, means for using the dual port memory as a random access memory of the main memory of the remote data input / output control device may be provided. That is, as the operation of the remote data input / output control device 100, when there are few process input / output devices connected to the transmission line, an empty area is created in the dual port memory, and this is used to cause an abnormality in the main memory 112. In this case, the mode in which the area in the dual port memory 116 or 117 is used as a backup area is provided.

FIG. 5 shows a remote data input / output control device 10
FIG. 3 is a schematic diagram showing an address configuration of 0 memory. Normally, the main memory 112 uses addresses 0000 to 7FFF. Dual port memory 116 has address E000
~ EFFF is assigned, but not all are used. Dual port memory 117 has addresses F000-FF
FF is assigned, but not all are used.
When an abnormality is detected in 7F00 to 7FFF in the area of the main memory 112, the processor 111 transfers the data to be accessed in 7F00 to 7FFF to the addresses EF00 to EFFF in the dual port memory 116 to access the data. This allows
It is possible to prevent the loss of function of the remote data input / output control device due to a single main memory failure.

[0037]

According to the first aspect of the present invention, since the duplicated data transmission control unit and the dual port memory corresponding to 1: 1 are provided, it is possible to use the input data from both transmission lines. Therefore, the switching performance when a failure occurs in the transmission path can be improved, and the reliability of the received data can also be improved.

According to the second aspect, the data reliability is emphasized by providing two modes, a mode in which input data from both transmission lines is used and a mode in which only input data from either transmission line is used. It is possible to select whether to prioritize processing speed or not, and it is possible to realize the optimum device for the system.

According to the third aspect, by providing the mode in which only the input data from one of the transmission lines is used, it is possible to realize an apparatus most suitable for a system in which processing speed is emphasized.

According to the fourth aspect, by providing the mode in which only the input data from one of the transmission lines is used, it is possible to realize an apparatus most suitable for a system in which processing speed is emphasized, and moreover, important data is lost. Fear can be reduced.
According to claim 5, the reliability can be improved by having the mode in which the dual port memory can be used as the backup memory of the main memory.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment.

FIG. 2 is a schematic diagram of a format of a dual port memory according to an embodiment.

FIG. 3 is a schematic diagram of a format of a dual port memory according to an embodiment.

FIG. 4 is a schematic diagram of a format of a dual port memory according to another embodiment.

FIG. 5 is a schematic diagram showing an address configuration of a remote data input / output control device of another embodiment.

FIG. 6 is a conventional block configuration diagram.

[Explanation of symbols]

100 ... Remote data input / output control device, 200, 300, 400 ... Process input / output device, 111 ... Processor, 112 ... Main memory, 113, 114, 221, 222, 331, 332, 441, 442 ... Transmission controller, 116, 117… Dual port memory.

Claims (5)

[Claims] 1. A management station having two data transmission control units, a duplexed transmission line connected in correspondence with the two data transmission control units of the management station, and the duplexed transmission line. In a data transmission device having a plurality of slave stations having two data transmission control units provided correspondingly, the management station has a dual port memory corresponding to the data transmission control unit of the management station at a ratio of 1: 1. A data transmission device comprising: 2. The management station comprises an operation mode in which normal data is selected from data in two dual-port memories and used, and an operation mode in which only data in one of the dual-port memories is used. The data transmission device according to claim 1, further comprising: 3. The management station is provided with an operation mode that uses only the data in the other dual-port memory when a plurality of abnormalities are continuously detected in the data in the one dual-port memory. The data transmission device according to claim 1. 4. The management station, when an abnormality is detected in data of a specific slave station in one of the dual port memories,
2. The data transmission device according to claim 1, further comprising an operation mode in which only data in the other dual port memory is used. 5. The data transmission device according to claim 1, wherein the management station uses the dual port memory as a backup of the main memory.