JP2723281B2 - Remote monitoring and control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a high-level data link control procedure (hereinafter referred to as a "high-level data link control procedure").
The present invention relates to a remote monitoring control device that transmits information necessary for monitoring and controlling a controlled device between a control station (master station) and a controlled station (slave station) using an HDLC transmission method).

(Prior Art) Conventionally, in a remote monitoring control device that transmits information between a master station and a slave station using the HDLC transmission method, the accuracy of time information added for the purpose of analyzing accident information is improved. In addition, the time is regularly adjusted between the master station and the slave stations.

FIG. 4 shows an example of a schematic configuration thereof, and FIG. 5 shows a state of an interrupt signal transmitted from the master clock. In FIG. 4, the relationship between the master station and the slave stations is shown as a one-to-one case. That is, in FIG. 4, the master station A is composed of a main microprocessor 41 and a sub-microprocessor 42 provided separately from the main microprocessor 41. An interrupt signal is input at a period (T), for example, every minute.

On the other hand, the slave station B comprises a main microprocessor 44 and a sub-microprocessor 45 provided in the transmission section.

In the remote monitoring control apparatus having the above configuration, in order to set the time between the master station and the slave station, the master clock 43 sends the sub-microprocessor 42 of the master station A to the sub-microprocessor 42 at a fixed period (T), for example, every minute. Is sent. At this time, in the master station A, a fixed period T ₀ (T <T ₀ ) set in advance in a timer (not shown) provided therein, for example, a timer input from the master clock 43 every hour. The time synchronization data is transmitted to the slave station B according to the input signal. FIG. 5 shows the state of the signal. T ₀ is a period in which time synchronization data is transmitted at regular intervals to start time adjustment.... T _n−1 , T _n , T _{n + 1} ,. , …… (I _n-1 ),
(I _n ), (I _{n + 1} ),... Are interrupt input signals from the master clock at the time of interrupt input.

Then, the master station A interrupts the current transmission protocol processing with the slave station a predetermined time (t ₀ ) before the interrupt input signal (I _n ) is input at the time of the start of the time adjustment, and the interrupt input signal ( I _n ) Enter wait state. In this case, the interrupt signal from the master clock 43 is input to a sub-microprocessor 42 different from the main microprocessor 41, so that processing for the interrupt input signal is performed exclusively. Therefore, the error factor of the delay time (t ₁ ) can be minimized as compared with the case where the main microprocessor 41 performs the input process for the interrupt signal from the master clock 43.

When the master station A enters the waiting state for the interrupt input signal, the flag defined by the HDLC transmission procedure (the 8 bits of 01111110) is used.
Start transmission. Therefore, it is possible to establish bit synchronization even when using an asynchronous modem.

Next, when an interrupt signal is input to the sub-microprocessor 42 at the transmission end time adjustment start time (T _n ) of the flag, the master station A shifts to time synchronous data transmission processing.
The time synchronization data is transmitted, and the time is adjusted for the slave station B.

Figure 6 shows the state of a state with the transmission data to the interrupt processing in the input processing slave station B of the interrupt signal in the parent station A, t ₁ is delayed with respect to the input process of the master station interrupt signal time (transmission data state transmission protocol), t _u is undefined delay time (transmission state flag transmitted) at 0-8 in the range of bits in the interrupt reception wait state, t ₂ is the time synchronous data transmission processing time (transmission state of time synchronization data transmission), t ₃ is a transmission path delay time of the time synchronization data, including the Tsu搬delay in the modem, t ₄
Is the slave station interrupt processing delay time until the time synchronization data at the slave station B is interrupted and input and the time adjustment is completed.

The added value of the time delay until (t ₁ ), (t _u ), (t ₂ ), (t ₃ ), and (t ₄ ) becomes the time data correction value (Δt),
Conventionally, in the slave station, the time is adjusted by adding the value of (Δt) to the received time data.

Further, in the remote monitoring control apparatus having such a configuration, a transmission format for performing time adjustment between the master station and the slave station is an HDLC transmission procedure format as shown in FIG. Here, the information field includes the station address corresponding to the slave station B shown in FIG. 4 and time synchronization data for time adjustment.

(Problems to be Solved by the Invention) As described above, in the conventional method of transmitting time data from the master station to the slave station and adjusting the time in the remote monitoring and control apparatus, the slave station may be reset for some reason such as an overflow of the reception buffer. When the time synchronization data is not received in the above, a retransmission request is made to the master station according to the HDLC transmission procedure, and the time synchronization data is sent again from the master station.

In this case, even if the time synchronization data is successfully received in the slave station B by one retransmission, the normal time data correction value (Δt) is obtained by a new indefinite delay time (t _r ) due to the retransmission procedure during that time. However, there is a disadvantage that correction cannot be performed.

Further, the retransmission request in this case is defined by the system.
It is performed up to the number of retransmission requests in the HDLC transmission procedure, and there is a possibility that the time lag will further increase. In addition, slave station B
The slave station interrupt processing delay time (t ₄ ) until the time synchronization data is interrupted and input and the time adjustment is completed is determined by the time until the transition to the interrupt processing accompanying the processing state in the slave station B. Includes variable delay factor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a remote monitoring control device that can improve the accuracy of time setting in a slave station.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention performs transmission protocol processing in accordance with HDLC transmission means, and controls a control station (master station) and a controlled station (slave station). In a remote monitoring control device that monitors and controls a controlled device by transmitting information necessary for monitoring control between the master station, the master station fetches an interrupt signal sent from the master clock at regular intervals, and Means for recognizing that the input signal is a time to start time adjustment, and when the signal to start time adjustment is recognized a predetermined time before every hour after the time adjustment start time, UI (Unnumbered Informatio) in defined control field
n) means for generating time cycle data for time adjustment configured by a command, and transmitting the time cycle data by interrupting the transmission protocol processing with the current slave station; Means for determining whether the data is time-synchronized data composed of a UI command when receiving time-synchronized data sent from the master station, and determining that the determination result is based on the UI command If the reception fails, the means for discarding the received data without making a retransmission request to the master station even if the reception fails, and when the determination result is determined not to be based on the UI command, the received data is the data. Means for processing as an error.

(Operation) When the time information from the master clock is input to the main microprocessor via the input unit 11, the master station determines whether the time information is the time to start the time adjustment. Here, when it is determined that it is time to start the time adjustment, the transmission unit 13 is notified of that. Next, when a signal to start time adjustment is output from the master clock, the transmission unit 13 generates time synchronization data constituted by a UI command. If it is determined at the start of the time adjustment that the current time is before a predetermined time (t ₀ ) at which the interrupt input signal (I _n ) is input, the current transmission protocol processing with the slave station is interrupted, and the HDLC transmission procedure is performed. Start transmission of the flag defined in. After the input of the interrupt signal, the transmission unit 13 performs a transmission process of the time synchronization data.

Next, the slave station performs the time synchronization data interrupt processing,
Determine whether this is time-synchronized data composed of UI commands, and if it is determined to be a UI command, discard the received data without requesting retransmission even if reception fails .

(Example) Hereinafter, an example is described with reference to drawings.

FIG. 1 is a block diagram of an embodiment of a remote monitoring control apparatus according to the present invention, showing a case where the relationship between a master station and a slave station is one-to-one.

In FIG. 1, reference numeral 10 denotes a master clock, which generates an interrupt signal at regular intervals (T) in order to set the time for the slave station B. The master station A includes an input unit 11, a main microprocessor 12, and a transmission unit 13. The input unit 11, the main microprocessor 12, and the transmission unit 13 are connected to each other via an internal bus. The function of each component will be described below.

The input unit 11 takes in the time information from the master clock 10 and transfers it to the main microprocessor 12 through the internal bus. When the main microprocessor 12 receives the time information from the input unit 11, it has a function of recognizing an interrupt input signal for time setting for the slave station. For example, T = 1 minute, T ₀ = 1 hour When the time is adjusted every hour, when the main microprocessor 12 recognizes one minute before the hour, the main microprocessor 12 notifies the transmission unit 13 of the fact. The transmission unit 13 performs a transmission process such as a transmission protocol of the HDLC procedure, receives an interrupt signal transmitted from the master clock 10 at regular intervals, and includes a sub-microprocessor. And this transmission unit 13
When a signal one minute before the hour is input from the main microprocessor 12, it recognizes that the next interrupt input signal to be output from the master clock 10 is a signal to start time adjustment, and, at the same time, recognizes the HDLC transmission procedure. Generates time synchronization data for time adjustment configured by a UI (Unnumbered Information) command in the control field defined in the above.

Further, the transmission unit 13 interrupts the current transmission protocol processing with the slave station before a predetermined time (t ₀ ) at which the interrupt input signal (I _n ) at the time of the start of the time adjustment is input, and performs the HDLC transmission. It has the function of starting transmission of the flag defined in the procedure and entering a state of waiting for an interrupt input signal (I _n ).

On the other hand, the slave station B has the same configuration as the conventional configuration shown in FIG.
That is, the sub-microprocessor in the transmission unit 15 processes the time synchronization data from the master station by interruption. However, in the slave station B, the transmission unit 15 includes means for performing the following input processing when time synchronization data cannot be received due to some reason such as overflow of the reception buffer. That is, since the received time synchronization data is composed of UI commands, even if the reception of the time synchronization data fails, the received data is discarded according to the HDLC transmission procedure without shifting to the retransmission request.

Next, the operation of the remote monitoring control device having the above configuration will be described with reference to the flowchart shown in FIG.

First, in step S21, when the time information from the master clock 10 is input to the main microprocessor 12 via the input unit 11, the time information is used to start the time adjustment, for example, one minute before the hour. It is determined whether or not. If it is determined that it is time to set the time, step S2
In 2, the transmission unit 13 is notified of the fact. Step transmitting unit 13 in S23, the next interrupt signal which is output from the master clock 10 (I _n) is, at the same time recognizes that it is a signal to start the time-setting, and time synchronization at UI command Generate data. If it is determined in step S23 that the current time is before a fixed time (t ₀ ) before the interrupt input signal (I _n ) is input at the time of starting the time adjustment, step S25 is performed.
Suspends the transmission protocol processing with the current slave station at
Start transmission of the flag defined in the transmission procedure. When the input of the interrupt signal (I _n ) is recognized in step S26, in step S27, the transmission unit 13 performs a process of transmitting time synchronous data. Through such processing, the time synchronization data is sent from the master station A to the slave station B via the transmission path.

On the other hand, the slave station B performs an interrupt process of the time synchronization data in step S28. In step S28, it is determined whether or not the time synchronization data is configured by the UI command,
If it is determined in S29 that the received command is a UI command, the received data is discarded in step S31 without shifting to the retransmission request even if the reception fails in step S30. If it is not a UI command in step S29, an error processing is performed as a data error in step S32.

As is clear from the above embodiment, since the process does not shift to the retransmission request of the time synchronization data in the slave station, a new indefinite delay time (t _r ) accompanying the retransmission procedure can be eliminated, and Can be improved when the time is adjusted.

In the above embodiment, the case where the time synchronization data is constituted by the UI command has been described. However, the present invention is not limited to this, and the address field may be a global address. Thus, even in a configuration in which the relationship between the master station and the slave stations is 1: n as shown in FIG. 3, data can be transmitted simultaneously and simultaneously, and each slave station can simultaneously transmit the time synchronization data. Since the data is captured, the accuracy of the error between slave stations can be improved.

The other internal processes in the parent and slave stations are exactly the same as in the above embodiment. Finally, data loss due to not performing the retransmission request process can be dealt with by a method of transmitting the time synchronization data, which has been performed every hour, every 30 minutes, for example.

As is clear from the above-described embodiment, in the slave station, after inputting the time synchronization data from the master station in advance, temporarily suspending other processing and preparing for the start of execution of the next time adjustment. The factor of the indefinite delay time included in the delay time (t ₄ ) can be eliminated, and the accuracy of time adjustment in the slave station can be improved.

[Effects of the Invention] As described above, according to the present invention, when time-synchronous data is transmitted, an indefinite delay factor accompanying a retransmission procedure,
An object of the present invention is to provide a remote monitoring control device capable of improving the accuracy of time setting for a slave station by removing an indefinite delay factor included in an interrupt processing delay time in the slave station. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a remote monitoring control apparatus according to the present invention, FIG. 2 is a flowchart for explaining the operation of the embodiment, and FIG. 3 is a configuration showing another embodiment of the present invention. FIG. 4, FIG. 4 is a block diagram showing an example of a conventional remote monitoring control device, FIG. 5 is a diagram showing the state of an interrupt input signal from a master clock, and FIG. FIG. 7 is a diagram showing a state of transmission data, and FIG. 7 is a diagram showing a format of an HDLC transmission procedure. DESCRIPTION OF SYMBOLS 1 ... master station, B ... slave station, 10 ... master clock, 11 ... input part 12 ... master station main microprocessor, 13 ... master station transmission part 14 ... slave station main microprocessor, 15 ... slave station transmission part

Claims (1)

(57) [Claims] 1. A transmission protocol process is performed in accordance with HDLC transmission means, and information necessary for monitoring and control is transmitted between a control station (master station) and a controlled station (slave station) to monitor and control a controlled device. In the remote monitoring control device, the master station captures an interrupt signal transmitted from the master clock at regular intervals, and recognizes that the interrupt signal is a time to start time adjustment. When a signal to start time adjustment is recognized a predetermined time before every hour after the adjustment start time,
In the control field defined in the HDLC procedure
In addition to generating time synchronization data for time adjustment consisting of UI (Unnumbered Information) commands,
A means for interrupting the current transmission protocol processing with the slave station and transmitting the time synchronization data is provided. When the slave station receives the time synchronization data sent from the master station, the data is configured by a UI command. Means for determining whether or not the received time-synchronized data is obtained, and, if the result of the determination is determined to be based on a UI command, requesting a retransmission to the master station even if reception fails. A means for discarding the received data, and a means for processing the received data as a data error when it is determined that the determination result is not based on a UI command.