JPS6355257B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote monitoring and control device that centrally monitors and controls a plurality of slave stations using one master station, and particularly relates to a remote monitoring and control device that shortens scanning time and improves data transmission efficiency. It is something.

As shown in FIG. 1, n slave stations S1, S2,
There is a system in which a common master station CC is installed for S3, .
In order to simplify the explanation, a 1:N type centralized monitoring and control system will be described. When a master station is installed in one place in the system, the reception counter sequentially scans from the first slave station to the nth slave station. Even if there are idle slave stations, etc., all slave stations are scanned, resulting in a disadvantage that the scanning time becomes long. Particularly when a suspended slave station is undergoing expansion or modification work, there is a risk of erroneous control and other inconveniences.

The purpose of the present invention is to shorten scanning time and improve data transmission efficiency by skipping scanning for slave stations that are scheduled to be added in the future or that are suspended due to expansion/modification work. An object of the present invention is to provide a remote monitoring and control device that can improve safety during work.

In order to achieve the above object, the features of the present invention are as follows:
The master station is equipped with a slave station reception counter that increments by one operation when the last word of information from one slave station is detected, and its output signal becomes a signal that designates the next slave station to receive information. The master station is provided with a slave station suspension setting means for performing a suspension operation when the slave station is suspended, and a suspension station designation detecting means for detecting that the output signal of the slave station suspension setting means and the output signal of the slave station receiving counter have a predetermined relationship. , the slave station reception counter is incremented by one operation each time there is an output from the idle station designation detection means, and as soon as a slave station that has been suspended is designated by the output signal of the slave station reception counter, the slave station reception counter is incremented by one operation. advance,
As a result, the designated slave station is moved to the next one without acquiring information from the slave station that has been suspended, and in the case of a non-dormant station designation, the counter increment interval is changed depending on the slave station data word length. It is that you are.

The present invention will be explained below with reference to the drawings.

The n slave stations S1 to Sn are designed so that the device power can be turned on and off at will, and are designed and manufactured so that data can be transmitted cyclically in order to simplify the device. Therefore, the state in which data from the slave stations S1 to Sn is received by the master station is random as shown in FIG. Furthermore, data for each slave station generally has different word lengths due to differences in equipment capacity and the minimum necessary word structure to minimize data update time.
The master station cyclically stores such data in the order of slave station numbers S1, S2, S3, S as shown in Figure 2.
4, ..., Sn, S1, S2, ... are received.
This is the operation when all the slave stations are installed, but if we consider, for example, the case where the second slave station S2 is inactive, as shown in "before application of the present invention" in Fig. The operation is the same as when all the slave stations are installed, except that the second slave station S2 has missing data.

In this way, with conventional technology, when there are a large number of unimplemented slave stations or a large number of slave stations that are temporarily inactive due to modification work, the data update time becomes longer even though the number of slave stations that are actually in operation is small. It turns out.

Next, the operation will be explained with reference to FIG. In Figure 3, SW1, SW2, SW3, SW4, ...,
SWn is a slave station suspension setting device provided in the present invention, A11, A12, A13, A14,...
..., A1n and A21, A22, A23, A2
4,...,A2n is an AND gate, OR1, OR
2 and OR3 are OR gates, 1 is a rising differentiation circuit, 2 is a decoder, 3 is a slave station reception counter, 4 is a falling differentiation circuit, 5 is a final word detection circuit, and 6 is a parallel-to-serial conversion circuit. ANDGATE A ₁₁
~A ₁₄ , the OR gate OR ₁ and the differentiating circuit 1 form the idle station designation detection means set forth in the claims. While receiving data from the first slave station S1, the AND gate A21 opens the gate and the data received as a serial signal via the OR gate OR3 is output as a parallel signal word by word by the serial/parallel conversion circuit 6.
Among these, the final word of the first slave station S1 is detected by the final word detection circuit 5, and its falling edge is detected by the falling differentiation circuit 4, and the slave station reception counter 3 is incremented by one operation. As a result, the AND gate A21, which had been open until now, is closed by the decoder 2.
The next AND gate A22 opens the gate and receives data from the second slave station S2. Thereafter, data is sequentially received from the third slave station S3, the fourth slave station S4, and so on.

Up to this point, both the conventional device and the device of the present invention are the same. On the other hand, in the case of the present invention in which slave station suspension setting devices SW1 to SWn are provided, the operation is as follows. If all the slave station pause setting devices SW1 to SWn are left open, the operation is the same as that described above. If we now consider that the second slave station S2 is a slave station scheduled to be adopted in the future or a slave station suspended for modification work, the corresponding slave station suspension setting device SW2 is closed. With SW2 closed, when the first slave station S1 completes reception and detects the final word, the slave station reception counter 3 increments one step by the output from the falling differentiation circuit 4, and the output from the decoder 2 Therefore, the AND gate A12 generates an AND output (since SW2 is already closed), the rising edge of which is captured by the rising differentiation circuit 1, and a pulse output is generated, and this pulse output is used again to input the slave station reception counter. 3 advances by one action and enters the state of the third slave station S3, and the output of the decoder 2 causes the AND gate A23 to open its gate, thereby converting the serial signal of the third slave station S3 from serial to parallel. Input to circuit 6. Next, at the falling edge of the final word of the third slave station S3, the slave station reception counter 3 is similarly incremented by one operation, and the AND gate A24 is opened to receive the fourth slave station S4. In the same way, in the case of a slave station corresponding to the closed setting device among the slave station pause setting devices SW1 to SWn, step by step,
It automatically advances one step and skips over the receiving slave station.

Time charts of the signals of each part of the circuit of the embodiment shown in FIG. 3 are shown in FIG. 4 when no idle station is set, and in FIG. 5 when the second slave station S2 is set as an idle station.

In this way, the slave station whose slave station pause setting device is closed becomes the same as being disconnected without stopping the master station common to all slave stations, even though it is connected to the device. Expansion or modification of slave stations can be carried out safely and easily, and data update time can be shortened.

In the above embodiment, a case has been described in which the centralized monitoring and control device uses a 1:N method for monitoring and the data word lengths are uneven. The present invention can be applied to devices of one system or devices of systems with the same data word length, and similar effects can be produced.

As explained above, according to the present invention, by providing a slave station pause setting device for each slave station on the master station side, it is possible to prevent erroneous control, improve workability, and shorten data update time. There is.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram of a conventional device, Fig. 2 is an explanatory diagram of a data reception situation, Fig. 3 is a circuit diagram of an embodiment of the present invention, Fig. 4 is a time chart of signals of each part when no idle station is set, FIG. 5 is a time chart of various signals when the second slave station is set as a dormant station. 1... Rising differential circuit, 2... Decoder, 3...
...Slave station reception counter, 4...Falling differentiation circuit, 5
...Final word detection circuit, 6...Serial-to-parallel conversion circuit,
SW1 to SWn...Slave station pause setting device.

Claims (1)

[Claims] 1. In a remote monitoring and control device that centrally monitors and controls multiple slave stations by sequentially specifying them one by one using a master station, one step is taken when the last word of information from one slave station is detected, and the output signal is used as the next information. A slave station reception counter that is a signal for specifying a slave station to receive data, a slave station suspension setting means for performing a suspension operation for each slave station, an output signal of the slave station suspension setting means, and an output signal of the slave station reception counter. Inactive station designation detection means for detecting that a predetermined relationship has been established is provided in the master station, and the slave station reception counter is incremented by one operation each time there is an output from the inactive station designation detection means; A remote monitoring and control device characterized in that, when a station is designated as a dormant station, a counter increment interval is changed depending on the slave station data word length.