JPS61123226A - Supervisory method of transmission system data - Google Patents

Abstract

PURPOSE:To detect an abnormality of transmission system data by storing two different reference voltages selected alternately at a period in a memory at the receiver side via a transmission system and comparing contents of the memory before and after the update. CONSTITUTION:A measuring data W converted into an analog value of a proper level by a converter 1 and a reference voltage S1 or a common voltage S2 of a DC voltage source 6 selected alternately by a switch 9 are multiplexed by a multiplexer 2 and transmitted to a transmission line 5a via an analog- digital converter 3, a serial/parallel converter 4 and a modulator 5. Thus, the data W and S1 and the data W and S2 are stored alternately in the memory 8 of the receiver 7. Since the data S1 and S2 are not equal, if the contents of the memory 8, the data S1 and S2 are compared and they are coincident, an abnormality of the switch 9 or the multiplexer 2 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for supervising m transmission data transmitted during data transmission and reception between electrical stations.

[Conventional technology]

No. 6 is a block diagram showing a conventional transmission data monitoring method for monitoring AC power data measured at an electric power station and transmitted via a transmission system. The obtained data is converted into an analog value of an appropriate level representing the fixed width of 7. 2 is a multiplexer that multiplexes the data of converter 1, and 3 is an analog-to-digital converter (hereinafter abbreviated as ADC), which multiplexes the data from converter 1. Convert the data in step 2 into digital value data. 4 is a parallel-to-serial converter that converts the ADC 3 into bit-serial data; 5 is a modulator; the parallel-to-serial converter 5
It converts the data into a transmission signal in the format shown in No. 7@, and transmits it to the receiver T of another electric station via the transmission line 5at. 8, the data from the receiver T is stored in the memory as shown in FIG.

W, diagram 7 shows the history of modulator 5? 5 is a format diagram of number 5a. In the figure, W indicates the data of the converter 1, and S indicates the data of the reference voltage generated by the reference voltage source 6.

FIG. 8 is a data layout diagram showing the data contents of the memory 8, and data W and S? Store it in the location shown.

Explain the action to the arrow. When the transmission equipment including the multiplexer 2 to the receiving island T shown in the sixth factor, that is, each part of the transmission system is functioning normally [the converter 1 and the reference voltage source 60
The reference voltages are alternately selected by multiplexer 2 n, A
The data is digitized by the DC 3, converted into bit-serial data by the parallel-to-serial converter 4, and further converted into a transmission signal by the modulator 5, which is sent to the transmission line 5a. In this case, data W and S as shown in FIG. 7 appear alternately in the transmission signal.

Here, for example, an abnormality occurs in the multiplexer 2.

When only the reference voltage of the reference voltage source 6 is selected, the transmission signal frame contains only data S as shown in FIG. 9, and the data S is stored in the memory 8 every cycle as shown in FIG. Only t is stored.

However, even if the receiver 7 side encounters an abnormal state in which only the data S is written fn to the memory 8, such an abnormal state cannot be detected unless the data S contains transmission error pits or the like.

[Problem that the invention seeks to solve]

The conventional transmission system data monitoring method is configured as described above, so even if the data from the reference voltage source is correctly received, the multiplexer stops as shown above, and the multiplexer converts the output of the converter to the ADC. If the reference voltage source remains connected to the multiplexer when it should be connected to the multiplexer, the data in the frame converter will be replaced by the data from the reference voltage source, but the receiver will not be able to use the received data. The problem was that data abnormalities could not be detected unless there were errors.

The present invention was made to solve the above-mentioned problems of the conventional methods, and therefore provides a transmission system monitoring method that can detect that the data to be monitored is correctly transmitted to the receiving side. The purpose is to

[Means for solving problems]

A method for monitoring transmission system data according to the present invention includes alternately selecting two reference voltages having different values at a certain period, and cyclically storing them in a specific location of a memory on the °C receiver side via the transmission system. 5, the validity of the transmission system data is monitored by comparing the contents of the specific location of the memory in which the reference voltage is stored before and after updating.

[Effect]

In this invention, the memory is updated with data of two reference voltages at regular intervals.

The contents of the specific location in the memory that stores the reference voltage before and after the update are compared, and if the contents are the same, the data is transmitted via the transmission line and receiver etc. that transmits the data. It is determined that there is an abnormality in the transmission system data obtained by -f.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, numerals 1 to 8 denote the same or equivalent parts as those shown in FIG. 6. 9a is a switch that alternately selects the reference voltage of the DC voltage source 6 and the ground voltage as another reference voltage at a constant cycle and inputs the selected values to the multiplexer 2.

In this case, the voltage S of the DC voltage source 6 is not equal to the ground voltage.

FIG. 2 is a format diagram of the transmission signal sent from the modulator 5 to the transmission line 5a, where W is the data of the converter 1, 81
2 shows data on the reference voltage of the DC voltage source 6 and data on the S2a ground voltage.

FIG. 3 is a data arrangement diagram showing the contents of the memory 8, and shows that data W and S□ and data W and S2 are stored in the memory 8 alternately as indicated by arrows in accordance with reception of transmission signals.

Let me briefly explain the operation. When each part of the transmission system shown in FIG. Since all voltages are selected alternately, the outputs U and Al of multiplexer 2
) C3, parallel to serial converter 4, and modulator 5 to become a transmission signal in the format shown in FIG.
sent upwards. Therefore, the data W and S and the data W and S2 are alternately stored in the memory 8 on the side of the receiver 7. Since the contents of data S and S2 are not equal,
By checking this content, for example, the function of the multiplexer 2 can be calibrated. If the switch 9 or the multiplexer 2 becomes abnormal and only the reference voltage of the DC voltage source 6 is selected, the transmission signal will contain only the data S as shown in FIG. The contents of 8 also include only data S1. Therefore.

The contents of data S1 or 52t in memory 8 are the same and when the contents of both are compared, they match, so it is detected that an abnormality has occurred in switch 9 or multiplexer f'2. can do.

〔Effect of the invention〕

As described above, the present invention can reduce the power of one generator by 50%.
Even when transmitting measured quantity data with little change, the system is configured to check the contents of the memory on the receiver side, so abnormalities in each part of the transmission system can be detected correctly, and data with high potential for damage can be detected. It has a cooling effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a transmission device illustrating a transmission system data monitoring method according to an embodiment of the present invention, FIG. 2 is a format diagram of a transmission signal of the modulator shown in FIG. 1, and FIG. 4 is a format diagram showing the contents of the transmission signal shown in FIG. 2; FIG. 5 is a data arrangement diagram showing the contents of the memory shown in FIG. 1;
Fig. 6 is a block diagram of a transmission device explaining a conventional transmission system data monitoring method, Fig. 7 is a format diagram of the transmission signal of the modulator shown in Fig. 6, and Fig. 8 is a diagram of the format of the transmission signal of the modulator shown in Fig. 6. FIG. 9 is a format diagram showing the contents of the transmission signal shown in FIG. 7; FIG. 10 is a data layout diagram showing the contents of the memory shown in FIG. 6. 2 is the multiplexer % 5a is the transmission line, T is the receiver, 8
9 is the memory, and 9 is the switch. Note that the same reference numerals in Figure 1 indicate the same and corresponding parts. Patent applicant Mitsubishi Electric Corporation Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] Two reference voltages with different values are alternately selected by a switch at a certain period, the data output from this switch and the data to be transmitted are multiplexed by a multiplexer, and the data from the multiplexer is converted into a transmission signal. , the data of the switch is transmitted to a receiver via a transmission path, and the data of the switch received via the receiver is stored in a specific location of a memory connected to the receiver in a format that is periodically updated, and the data is updated. A method for monitoring transmission system data, wherein the validity of the data to be transmitted transmitted via the transmission path is monitored by comparing the data at the specific position before and after the transmission.