JPS6324360B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote monitoring and control device using a microprocessor, and particularly to a remote monitoring and control device in which a slave station device is equipped with a non-volatile read/write memory and is controlled by a master station device. Regarding.

Conventionally, a remote monitoring and control device connects a control center device (hereinafter referred to as a master station device) and a controlled station device (hereinafter referred to as a slave station device) via a transmission path, and the remote monitoring control device It monitors the equipment in the control center and controls the equipment based on plant data set in the slave station device.

The above-mentioned plant data is usually semi-fixed or fixed, and changing the contents while the slave station device is in operation is generally not done because it involves temporarily stopping the device and changing the hardware.
In addition, in recent slave station devices using microprocessors, plant data is stored in a fixed memory such as a read/write memory (hereinafter referred to as
It is generally stored in a writable read-only memory (hereinafter referred to as PROM). Normally, the above RAM can be read and written freely, but if the power is turned off or a momentary power outage occurs, the stored data may be completely erased or the contents of the stored data may change. or Therefore, when the power is turned on again, the data in the RAM will be different from the data before the power was turned off, and necessary data must be reset again. on the other hand,
PROM does not change the contents of stored data when the power is cut off, but when increasing or decreasing equipment or changing data, a dedicated PROM eraser and writer are required, as well as writing data to the PROM. There is the inconvenience that the equipment must be stopped for a while.

In order to change semi-fixed or fixed plant data as described above, it is necessary to directly change the slave station device. In addition, remote monitoring and control equipment does not only have a one-to-one correspondence between a control center and a controlled station, but also generally has a large number of controlled stations corresponding to a single control station. For example, changes to plant data must be made for the number of controlled stations. This problem was very time-consuming and inconvenient, as each time there was a change, it was necessary to go to the controlled facility and make the change.

This invention was made in consideration of the above-mentioned circumstances, and its purpose is to cyclically transmit plant data from a master station device to a slave station device by putting it on transmission data, and to transmit this transmitted data to a slave station device. a first behavior circuit that determines the validity of the pattern signal given by activating the setting program upon acceptance;
A second behavior circuit that outputs a data write permission signal is activated by the output of the first behavior circuit to determine whether the pattern signal is valid and the data write command.
Writing of the plant data in the transmitted data to the non-volatile read/write memory is permitted based on the respective legitimate behavior operations in these first and second behavior circuits, and until the writing of the plant data Since the behavior is made to go through two behavior operations each time, the contents of the set plant data will not change even if the power is cut off. To provide a remote monitoring and control device that can reliably prevent erroneous writing and perform highly reliable remote monitoring and control.

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

In FIG. 1, reference numeral 1 denotes a master station device of a control station that controls slave station devices 2-1 to 2-n of a plurality of remotely located controlled stations. This master station device 1 always cyclically sends transmission data to the slave station devices 2-1 to 2-n each having a microprocessor in a corresponding controlled station in the format shown in FIG. It's summery. That is, as shown in FIG. 2, transmission data is first sent to a synchronization word 3 in a special form, followed by a setting word 4 for setting plant data, and then a selection control word 5 for selectively controlling equipment at the controlled station. A format of serial word data is constructed in the order of , and is constantly cyclically transmitted to the corresponding slave station devices 2-1 to 2-n.

The slave station devices 2-1 to 2-n are each provided with first and second behavior circuits shown in FIG. Third
In the figure, numeral 6 is a constant mark discrimination circuit that performs the first behavior. This fixed mark discrimination circuit 6 outputs a "1" signal when a fixed code is given to the data bus 7, and outputs a "0" signal when a wrong code is given. (hereinafter referred to as the FF circuit). The FF circuit 8 stores the constant mark discrimination result of the constant mark discrimination circuit 6, and receives the initial signal.
It is reset by S1, and the constant mark discrimination circuit 6
When a "1" signal is given from the AND circuit 9, a "1" signal is given, and when a "0" signal is given, a "0" signal is given to the AND circuit 9. The AND circuit 9 performs a two-behavior operation, and when it receives a “1” signal and a write signal S2 from the FF circuit 8, it sends a “1” signal to a non-volatile read/write memory (hereinafter referred to as N-RAM).
) give 10. The N-RAM 10 writes the plant data given to the data bus 11 by the setting program when a "1" signal is given from the AND circuit 9 after completing one behavior operation.

The operation of the apparatus configured as described above will be explained below.

First, the necessary plant data in the control center is set in the setting word 4, and this setting word 4 is set in the first
As shown in the figure, synchronization word 3 and selection control word 5
At the same time, the latest data is always sent cyclically from the control center to the controlled station through the transmission line as transmission data.

The sent configuration data is received by the slave station device for each frame. The slave station converts serial data into parallel data and checks whether there are any errors in the data. As a result, if there is an error in one word of data, for example, the data with the error is discarded, and the plant data is rewritten with a new word sent again in the next frame.

That is, if the setting data sent cyclically is correct, the setting program is activated to write data into the N-RAM 10. This setting program runs only the setting program with interrupt processing disabled, as shown in the flowchart shown in FIG. First, in order to enable writing into the N-RAM 10, a predetermined pattern is applied to the data bus 7 to the fixed mark discriminating circuit 6 shown in FIG. The fixed mark discriminating circuit 6 outputs a "1" signal if a fixed code is given, and outputs a "0" signal if a wrong code is given. If the output of the constant mark discrimination circuit 6 is a "1" signal, the FF circuit 8 supplies a "1" signal to the AND circuit 9. The operations up to this point complete one behavior.

After completing one behavior, the setting program outputs the write data onto the data bus 11 of the N-RAM 10 in the next step, and supplies the write signal S2 to the AND circuit 9. Since the AND circuit 9 is first given the "1" output of the FF circuit 8 due to the 1-behavior operation, the AND circuit 9 receives the "1" signal.
-RAM10 gate open command N-RAM10
give to Therefore, the N-RAM 10 writes plant data.

On the other hand, when the setting program that has written into the N-RAM 10 outputs a code other than the predetermined code to the fixed mark discrimination circuit 6 in the next step, the FF circuit 8 is inverted and the output is a "0" signal. becomes. Therefore, the output of the AND circuit 9 becomes a "0" signal, and the gate closing command called "0" signal becomes N-
N- is given to RAM10 by the setting program.
Even if a write operation is performed to RAM10, N-RAM
Unable to write data to 10. When a gate close command is issued, an interrupt processing permission command is issued.

On the other hand, in the worst case, if the same word causes errors in each frame, the transmission data transmitted from the control station to the controlled station will have N-
The data written in RAM10 is loaded and sent back to the control center, and the data set at the control center is compared with the returned data, and the data is transferred to the N-RAM of the actual slave station device.
Check at the control center whether the necessary plant data has been written to 10. As a result, N-RAM1
If the data written to 0 is correct, the process ends,
If the written data is incorrect, interrupt processing is prohibited again and the same processing as described above is performed.
The process is repeated until the data written in 10 is correct.

As described above, according to the present invention, plant data is set using the N-RAM 10 in the slave station device of a remote monitoring and control device using a microprocessor, and furthermore, the transmission format from the control center to the controlled station is set. Since we set up word 4 to control N-RAM10 online from the control center,
There is no need to stop the device in order to set or change the plant data of the slave station device, and there is no need to go to the controlled facility each time.

In addition, since the behavior operation is performed twice before writing the plant data, disturbances, noise,
It is possible to reliably prevent erroneous writing of plant data caused by program runaway, etc., and to perform highly reliable remote monitoring and control.

Note that this invention is not limited to the above embodiments. For example, in the embodiment described above, the behavior is performed twice, but the behavior may be performed twice or more.

As explained above, according to the present invention, plant data is placed on transmission data from a master station device and cyclically transmitted to a slave station device, and when this transmission data is received by the slave station device, a pattern is given by starting a setting program. A first behavior circuit that determines the validity of a signal, and a second behavior circuit that outputs a data write permission signal based on the pattern signal validity determination output from this first behavior circuit and a data write command are operated. Writing of the plant data in the transmitted data to the non-volatile read/write memory is permitted based on the respective legal behavior operations in the first and second behavior circuits, and by the time the plant data is written. Since the behavior operation is performed twice, the contents of the set plant data will not change even if the power is cut off, and errors in the plant data caused by disturbances, noise, program runaway, etc. will not occur. Therefore, it is possible to provide a remote monitoring and control device that can reliably prevent illegal writing and perform highly reliable remote monitoring and control.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention. FIG. 1 is a block diagram showing a remote monitoring and control device divided into a master station device and a slave station device, and FIG. 2 is a block diagram showing a remote monitoring control device divided into a master station device and a slave station device. FIG. 3 is a diagram showing a transmission format for transmission from a station device to a slave station device, FIG. 3 is a two-behavior operation circuit diagram, and FIG. 4 is a flowchart of a setting program for writing data to N-RAM. 1... Master station device, 2-1 to 2-n... Slave station device, 4... Setting word, 6... Constant mark discrimination circuit, 8... Flip-flop circuit, 10... Non-volatile read/write memory.

Claims (1)

[Claims] 1. A remote monitoring and control device that connects a control center and a controlled station via a transmission line, monitors the equipment of the controlled station from the control station, and controls the equipment using plant data set in the controlled station. a master station device installed in the control center and cyclically transmitting transmission data including the plant data to the controlled station; and a master station device installed in the controlled station receiving the transmission data transmitted from the master station device. Then, by starting the setting program, a predetermined pattern signal is given to a first behavior circuit that determines the validity of the pattern signal, and a data write command is issued on the condition that the first behavior circuit outputs a determination that the pattern signal is valid. a second behavior circuit that outputs a data write permission signal when given, and a slave station having a nonvolatile read/write memory into which the plant data in the transmission data is written by the data write permission signal of the second behavior circuit. A remote monitoring and control device comprising: