JPH0310265B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention transmits status change (hereinafter abbreviated as status change) data of plant equipment collected at a slave station of a remote viewing control device to a master station. The present invention relates to a state change data transmission device for use in a business, and more particularly to a state change data transmission device having a function of controlling the amount of data transmitted when a large number of state change data is generated.

[Background of the invention]

A remote monitoring and control device that monitors the status of plant equipment from a distance is composed of a master station 1 connected via a transmission line 2 to slave stations 31 to 3N that take in the status of plant equipment, as shown in FIG. As shown in Fig. 2, the master station 1 sequentially calls the slave stations 31 to 3N to collect the status of the plant equipment taken in by the slave stations 31 to 3N. Collect plant equipment status as status change data to improve data transmission efficiency on transmission lines. In this case, for example, the slave station 31 (the same applies to other slave stations) connects the status change detection circuits 81 to 8n to the plant equipment status 9 as shown in FIG. 2 is connected to a processing device 4 via an address signal 5, a data signal 6, and a read signal 7. Plant equipment status 9
FIG. 4 shows an example of the configuration of the state detection input circuit 81 (others are the same). The plant equipment status 9 is connected to a signal conversion circuit 10, and its output is input to a data terminal D of a DT flip-flop 12 and a front-to-edge differential circuit 11 for detecting a change in status. The output of the leading and trailing edge differentiating circuit 11 is input to the trigger terminal T of the DT flip-flop 12 and the set terminal S of the SR flip-flop 13. Therefore, each time a change in condition occurs
The SR flip-flop 13 is set, and the current state 9 (on, off) is set in the DT flip-flop 12. On the other hand, the address signal 5 from the processing device 4 is input to the address comparator 14 together with the output of the address setting circuit 16 which sets the address of the self-state change detection circuit 81, and the coincidence output is input to the AND gate 17 together with the read signal 7. It detects that a read instruction has been issued to its own circuit 81, opens gates 18 and 19 in response to the output, and sends the outputs of the DT flip-flop 12 and SR flip-flop 13 to the transmission line 2 via the processing device 4. At the same time, the output of the AND gate 17 is input to the trailing edge differentiation circuit 15, and at the time of falling, the SR flip-flop 13 is reset by the output from the circuit 15 in preparation for the occurrence of the next state change.

State detection power circuits 81 to 81 configured as described above
8n, if the plant equipment status 9 is a contact, etc., the on-resistance of the contact increases, and the threshold level of the signal conversion circuit 10 increases as shown in FIG.
When the output of the signal conversion circuit 10 fluctuates around L _t , the state change is detected by the front and rear edge differentiating circuits 11 each time, and the state change status is set in the SR flip-flop 13, and the state change data of the processing device 4 is detected. This increases the load for collection and increases the amount of data transmitted to the master station 1. For this reason, there was a drawback that more status change data than necessary was transferred to the master station 1.

[Purpose of the invention]

An object of the present invention is to add a function of interlocking the detection of a change in the state of plant equipment 9 in the slave station 3, eliminate unnecessary load on the processing device 4 for collecting status change data, and An object of the present invention is to provide a status change data transmission device capable of controlling the amount of data transmitted.

[Summary of the invention]

The present invention includes a table that stores enable data that is assigned to each state and indicates whether or not to interlock state change detection in the detection mechanism, and a table that stores enable data that is assigned to each state and indicates whether or not to interlock state change detection in the detection mechanism. and means for instructing the detection mechanism regarding the state whether or not to interlock state change detection.

[Embodiments of the invention]

FIG. 6 is an explanatory diagram of the operation of one embodiment of the method of the present invention. In this embodiment, once the master station 1 takes in the status change data of the plant equipment from the slave station 3, the contents are Accordingly, the indicated input enable data is transferred to the corresponding slave station. This data bitwise corresponds to the plant equipment status input, and is 1 when the input is enabled (no interlock applied) and 0 when the input is disabled (interlock applied). For this input enable data, for example, a table as shown in FIG. 7 is prepared for each plant device of each slave station 31 to 3N, and the contents of this table are set in the master station 1 depending on the situation such as a change in status. I'll keep it.
In other words, this table contains device status numbers 1 to 8N+
8, and the data is 1-bit enable data, where "1" means an instruction not to apply interlock, and "0" means an instruction to apply interlock. For example, if the data of number 4 is "0", it means an instruction to apply an interlock to state number 4. When the processing device 4 of the slave station receives this data,
As shown in the flowchart of FIG. 8, enable processing or disable processing of the relevant plant equipment status input data is executed. That is, when the state change detection of the relevant plant equipment state input is interlocked, disable processing is executed for the relevant state detection input circuit 8, and when the state change detection is not interlocked, the enable processing is performed for the relevant state detection input circuit 8. The plant equipment status to be interlocked may be one (one bit) or a plurality of plant equipment states such as word units.

FIG. 9 shows an embodiment of a state change detection input circuit (detection mechanism) 8 equipped with the above-mentioned interlock mechanism. The configuration of this embodiment is based on the conventional circuit shown in FIG.
1 and an interlock circuit consisting of an AND gate 22 is added, but the other configurations are the same. Therefore, the settings for the SR flip-flop 13 as to whether or not there is a change in condition;
DT flip-flop 12 of state change data at that time
The settings and read operations are basically the same as in the past. However, front and rear edge differential circuit 11
An AND gate 22 is inserted between the DT flip-flop 21 and the flip-flops 12 and 13. Therefore, when the output of the DT flip-flop 21 is 0, the detection of state change data is interlocked, and only when the output is 1, detection is possible. Therefore, the processing device 4 of the slave station sets the enable signal 24 and the write signal 23 to 1 when starting state change detection (enable processing) in order to control the state change detection of the plant equipment state of the state change detection input circuit 8. , sends an address signal 5 to the status change detection input circuit 8. Then, the output of the address comparator 14 of the state change detection input circuit becomes 1, and this and the write signal 23 of 1 cause the output of the AND gate 20 to become 1, setting the enable signal 1 to the DT flip-flop 21, and detecting the state change. becomes executable. In addition, when stopping status change detection (disable processing), enable signal 2
If 4 is set to 0, the DT flip-flop 21 of the status change detection input circuit is set to 0 in the same manner as described above, and the AND gate 22 is turned off, and the output of the leading and trailing edge differentiating circuit 11 according to the plant equipment status 9 is set to 0. is inhibited and condition detection is interlocked.

〔Effect of the invention〕

According to the present invention, by setting enable data in a table allocated for each state, it is possible to interlock state change detection for each plant equipment state of a slave station. Furthermore, it is possible to control the load for collecting status data on the processing device 4, and also to control the amount of data transmitted to the master station 1.
There is an advantage that connection and disconnection can be realized only by the processing of the slave station 3.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a remote monitoring and control device to which the present invention is applied, FIG. 2 is a diagram showing a time chart of conventional status change data collection and transmission in the remote monitoring and control device, and FIG. 3 is a diagram showing the configuration of a remote monitoring and control device to which the present invention is applied. FIG. 4 is a diagram showing an example of the configuration of a part related to collecting station status change data. FIG. 4 is a diagram showing a configuration example of a conventional status change detection input circuit. FIG. 5 is a diagram showing an example of status change detection when plant equipment status is abnormal. , FIG. 6 is a time chart of status change data collection according to the present invention, FIG. 7 is a diagram showing a configuration example of a plant equipment status input enable data table, FIG. 8 is a flowchart of received data processing in a slave station, and FIG. FIG. 9 is a diagram showing an embodiment of a state change input circuit for carrying out the method of the present invention. 1... Master station, 2... Transmission line, 31-3N... Slave station, 4... Processing device, 81-8n... Status change detection circuit, 9... Plant equipment status, 20... AND gate, 21 ...DT flip-flop, 22...
AND gate, 23...Write signal, 24...Enable signal.

Claims (1)

[Scope of Claims] 1. A state change data transmission device comprising a detection mechanism that detects state changes of plant equipment for each state, and a transmission means that transmits the state changes detected by the detection mechanism to a higher level, A table that stores enable data that is assigned to each state and indicates whether or not to interlock state change detection in the detection mechanism; and according to the enable data read from this table for each state, A state change data transmission device comprising: means for instructing a detection mechanism whether or not to interlock state change detection. 2. The status change data transmission device according to claim 1, wherein the enable data of the enable table can be arbitrarily set by a higher-level system.