JPH0556482A - Duplicate remote monitor controller - Google Patents

Abstract

PURPOSE:To realize duplication of transmission functions with a simple means and to attain multi-item and lots of transmission, high speed transmission and high efficiency transmission. CONSTITUTION:Master stations 1, 2 and slave stations 3, 4 are provided respectively with a sequence arithmetic operation function calculating a sequence including monitor control and system changeover and a start-stop transmission function and a programmable controller corresponding to duplicated transmission lines. Then the 1st master station 1, the 1st slave station 3, the 2nd master station 2 and the 2nd slave station 4 are connected by transmission lines 6, 7 via a MODEM and the various sequence is implemented based on the content of the arithmetic operation of the sequence of the programmable controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distant monitoring control device, and more particularly to a distant monitoring control device characterized by an information transmission function between a master station and a slave station.

[0002]

2. Description of the Related Art Conventionally, the Institute of Electrical Engineers of Japan cyclic digital information transmission system (established by the Institute of Electrical Engineers of Japan Communications Special Committee,
A distant monitoring control device (hereinafter abbreviated as TC / TM) complying with the specification standard of the CDT method has been used for monitoring control of various plants in remote locations.

The TC / TM of the CDT system is for transmitting a plurality of digital information cyclically sent from a master station / slave station to the slave station / master station in a predetermined order in a time division manner using a line. , Communication speed 1200 [bit / sec] or less,
Full duplex, NTT line 3.4 [kH _Z] in 4-wire,
The error test is based on the inverted double-transmission parity test.

[0004]

By the way, when a plant at a remote place is monitored and controlled, line disconnection or line congestion becomes a problem. In this case, it is possible to deal with this by making the transmission line a dual system of a normal line and a standby line, but in the conventional TC / TM, it was necessary to provide an external switching circuit to switch the transmission line.

Recently, there have been demands for multi-item mass transmission, high-speed transmission, and high-efficiency transmission including information indicating a state change, etc. In the conventional TC / TM based on the CDT method, the following principle is used. There was a limit.

(1) As described above, the specifications of the CDT method are 12
Since the communication speed is 00 [bit / sec] or less, high-speed transmission cannot be expected.

(2) Since the transmission format is specified in the cyclic method, the number of items that can be transmitted is limited, and when the status of the plant to be monitored and controlled changes, that information can be transmitted efficiently and preferentially. Difficult to do.

(3) An HLDC type TC / TM has been devised in addition to the cyclic type, but its processing is too expensive and the cost is high for a simple transmission device to which a programmable sequencer is applied. Absent.

(4) The inverted double-transmission parity check adopted as an error check method has high reliability, but on the other hand, the check bit is long, so that the transmission efficiency is low.

(5) Since it has a transmission function, but does not have a sequence control function, a separate sequence circuit is required when performing a logical operation based on the captured information.

The present invention has been made under such a background, and an object of the present invention is to realize duplication of the transmission function by a simple means and to enable multi-item mass transmission, high-speed transmission and high-efficiency transmission. The purpose is to provide a duplicated TC / TM.

[0012]

Dual TC / T of the present invention
M replaces the conventional CDT-based TC / TM with a dual system that connects a master station and a slave station via a transmission line to exchange information, and when an abnormality occurs in one of the systems due to the healthy check function. Is a system for automatically switching to the other system. Specifically, the master station and the slave station, the sequence calculation function for calculating the sequence of monitoring control and system switching, and the master station and the slave station, respectively. It is equipped with a start-stop synchronization type transmission function that can transmit information by either cyclic transmission method or state change transmission method depending on the sequence calculation content while taking switching synchronization.
In addition, it is characterized in that it is configured by using a programmable controller capable of supporting transmission line duplication.

The slave stations share a process input / output unit.

[0014]

Since the main constituent parts of the master station and the slave station are programmable controllers, the system structure can be downsized and simplified. Further, since each programmable controller has a sequence calculation function, it is possible to arbitrarily calculate and set the transmission format and the switching sequence. Furthermore, if an error occurs in one system including the transmission line due to the health check function, the switching sequence of the programmable controller automatically switches to the other system while synchronizing the master station with the slave station. -The system operation is continued without stopping the monitoring control function even at the time of inspection.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a dual TC according to an embodiment of the present invention.
It is a block diagram of / TM. In the figure, 1 and 2 are first and second master stations, and 3 and 4 are first and second slave stations, each of which is configured using a programmable controller.

Further, 5 is a switching R _Y sequence circuit for selecting a switching mode between "manual" and "automatic", 6 is an A-system transmission line, 7 is a B-system transmission line, and 8 is a common process input / output unit ( Common PI / O), 9 is a process section.

The programmable controllers used in each of the master stations 1 and 2 and the slave stations 3 and 4 operate in sequence while synchronizing the master station and slave stations with a sequence calculation function for calculating a sequence of supervisory control and system switching. CPU units 1b, 2b, 3b, 4b having a start-stop synchronization transmission function capable of transmitting information in either a cyclic transmission method or a state change transmission method depending on the contents of calculation
And direct connection data input / output units (direct connection DI / O) 1a, 2a, 3a, 4a, and redundant data input / output units (duplication DI / O) 1c, 2c, 3 for enabling transmission line duplexing.
c, 4c.

The redundant DI / O between the master stations 1 and 2 and the slave stations 3 and 4 and the direct connection DI / O between the slave stations 3 and 4 are directly connected to each other by data lines. Direct connection DI /
The O's are connected by a data line via the switching R _Y sequence circuit 5.

The CP of the first master station 1 and the first slave station 3
Us are connected to each other via a modem via an A system transmission line,
The CPUs of the second master station 2 and the second slave station 4 are connected to each other by a B-system transmission line via a modem. Furthermore, each slave station 3, 4
A common PI / O8 is connected to the CPU of
/ O8 exchanges information with the process 9.

Note that each of the master stations 1 and 2 communicates with a CRT oper computer, a console (CD) controller, and a graphic panel (GP) controller, which are provided as a central monitoring device via a local area network realized by a coaxial cable. It is carried out.

Hereinafter, a system in which the first master station 1 and the first slave station 3 are connected by the A system transmission line 6 via a modem is referred to as an A system, and the second master station 2 and the second slave station are described. A system in which 4 and 4 are connected by a B transmission line 7 via a modem is referred to as a B system, and one of the systems is set as a master (regular) and the other is set as a slave (standby). To do.

In the duplex system configured as described above, the operation of the CPU is basically the same for both the master and the slave, but the processing of the remote I / O scanner (not shown) is performed by each system. Different. That is,
Only the master sends and receives information to and from the shared memory (not shown), and the slave only receives. In addition to exchanging information by the data line, various control signals are exchanged between the master and the slave. In addition, a healthy check is performed to detect abnormalities in the partner system.

Next, an example of a sequence in the duplex TC / TM having the above configuration will be described.

2A and 2B are state explanatory views when an abnormality occurs in one of the master stations. FIG. 2A shows a state before the abnormality occurs and FIG. 2B shows a state after the abnormality occurs.

FIG. 2A shows that the A system is the master and the first master station 1 has failed. In this case, when the switching R _Y sequence circuit 5 is in the “automatic” mode, as shown in FIG.
Is automatically switched from master to slave with dual DI / O1c, and at the same time the second master station 2 is duplicated with DI / O2c.
Switch automatically from slave to master. This automatic switching is mainly performed by the slave CPU.

As the master station is switched, a slave station switching command is issued from the second master station 2 to the second slave station 4 in order to make the master / slave mode of the slave station the same as that of the master station. Is output. As a result, the second slave station 4 receives the duplicated DI / O.
4c switches from slave to master.

When the switching R _Y sequence circuit 5 is in the "manual" mode, the master / slave modes of the master stations 1 and 2 and the slave stations 3 and 4 can be manually switched.

3A and 3B are state explanatory views when an abnormality occurs on the slave station side or on one of the transmission lines. FIG. 3A shows a state before the abnormality occurs and FIG. 3B shows a state after the abnormality occurs.

FIG. 3A shows that the A system is the master, and the failure of the first slave station 3 or the transmission abnormality of the A system transmission line 6 has occurred. In this case, when the switching R _Y sequence circuit 5 is in the “automatic” mode, FIG.
As shown in FIG. 3, the first slave station 3 is automatically switched from the master to the slave by the redundant DI / O 3c, and at the same time, the second slave station 4 is automatically switched from the slave to the master by the redundant DI / O 4c. I / O for common PI / O8
Even when the scanner is abnormal, the master / slave mode of the slave station is similarly switched.

In the first master station 1 which is the master, A
The line status of the system transmission line 6 is monitored by a test data transmission check with the first slave station 3, but if there is an abnormality in this transmission line 6, transmission will not be possible. The master / slave mode of is automatically switched.

Each slave station 3, 4 can transmit the status of each slave station to the master stations 1, 2 except when there is a serious failure such as power failure. Therefore, the second slave station 4 that has become the master notifies the second master station 2 that the master / slave mode has been switched. As a result, the second master station 2 has its duplicated D
I / O2c switches from slave to master.

When the switching R _Y sequence circuit 5 is in the "manual" mode, the master / slave mode of the master station and the slave station can be manually switched.

As described above, in this embodiment, since the master stations 1 and 2 and the slave stations 3 and 4 are configured by using the programmable controller which has the transmission function and is compatible with the duplication,
The system configuration is significantly downsized and simplified.

Further, since the process I / O 8 on the slave station side is made common, there is no effect on the various plants due to the master / slave switching, and moreover, effective use of resources can be achieved.

Further, since each programmable controller is provided with the sequence operation function, the process 9 on the slave station side is performed.
In addition to the supervisory control function of various plants connected to, the transmission format and switching sequence can be arbitrarily calculated and set. It has become possible to perform priority transmission and high-efficiency transmission with specified information.
Moreover, in the case of duplication, it is not necessary to provide an external switching circuit as in the conventional case.

Further, since each programmable controller is provided with an asynchronous transmission function, in principle 9600
The transmission speed can be increased to about [bit / sec], and high-speed transmission is possible. Further, when an abnormality occurs in one system including the transmission path, the master station and the slave station are automatically switched to the other system while synchronizing with each other. Therefore, even during maintenance / inspection, the system operation can be continued without stopping the monitoring control function, and the reliability of the system can be improved.

In addition to the asynchronous transmission function, other transmission control procedures such as the HDLC method, JIS BASIC procedure, and BISYNC method can provide the same effect as the present embodiment in principle.

[0039]

As described above, according to the redundant remote monitoring and control apparatus of the present invention, it is possible to realize a dual transmission function by a simple means, and moreover, it is impossible or difficult in the past to transmit a large number of items. High-speed transmission and high-efficiency transmission are now possible or easy.

Further, since the external switching circuit provided in the conventional apparatus of this kind is not required and the switching is realized by the sequence operation, the failure relating to the switching circuit can be eliminated from the overall failure and the reliability is improved. Has become possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a duplicated remote monitoring and control device according to an embodiment of the present invention.

2A and 2B are state explanatory diagrams when an abnormality occurs in one of the master stations in the present embodiment, FIG.
Is a state diagram after an abnormality occurs.

3A and 3B are state explanatory diagrams when an abnormality occurs on one of a slave station side and a transmission line in the present embodiment, FIG. 3A is a state diagram before the abnormality occurs, and FIG. 3B is a state diagram after the abnormality occurs. ..

[Explanation of symbols]

1, 2 ... Master station (programmable controller), 3, 4
… Slave station (programmable controller), 5… Switching R _Y
Sequence circuit, 6, 7 ... Transmission line, 8 ... Common process input / output section, 9 ... Process.

Claims (2)

[Claims] 1. A system for connecting a master station and a slave station via a transmission line to exchange information is duplicated, and when an abnormality occurs in one system by a healthy check function, the system is automatically switched to the other system. In the dual distant monitoring and control device thus configured, the master station and the slave station, respectively, while performing a sequence calculation function for calculating a sequence including monitoring control and system switching, while switching the master station and the slave station, A programmable controller that has a start-stop synchronous transmission function that can transmit information in either cyclic transmission method or state change transmission method according to the sequence operation content and is compatible with transmission line duplication A featured dual distance monitoring and control device. 2. The dual distant monitoring and controlling apparatus according to claim 1, wherein the slave stations share a process input / output unit in common.