JPH012492A - Remote monitoring control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a remote monitoring and control device that transmits and receives signals using a polling method between a master station and a plurality of slave stations connected in a chain. be.

[Conventional technology]

FIG. 2 is a block diagram showing a conventional remote monitoring and control device disclosed in, for example, Japanese Unexamined Patent Publication No. 57-69496.
The part of the signal transmission system which is omitted in the above publication is shown in detail. In the figure, 0 is a master station, 1 and 2 are slave stations, and 3aib, 4ae, 4b+5a+5b are transmission lines connecting this master station O and each slave station 1, 2 in a chain. In addition, in the master station 0, 01 is the central processing circuit, 02
is a digital output circuit connected to the central processing circuit 01 by bus, 03 is a digital input circuit also connected to the central output circuit 01 by bus, 04 is a display panel connected to digital output circuit 02, and 05 is a digital input circuit 034C connection. 06 is a code transmitting/receiving circuit connected to the central processing circuit port 1 via a bus, 07 is a modulator connected between the code transmitting/receiving circuit 06 and the transmission line 3a, and 08 is a code transmitting/receiving circuit 06 and the transmission line 3b. A demodulator connected between the Furthermore, in slave station 1゜2, 10.20 is a central processing circuit;
11.21 is a digital output circuit connected to the central processing circuit 10.20 by a bus, and 12.22 is a central processing circuit 10.20.
Digital input circuit bus connected to 20, 13.23
10 and 20 are code transmitting and receiving circuits connected to the central processing circuit 10 and 20 by a bus, and 14a and 24b are transmission lines 3a from the master station side.

4a is a demodulator connected to 14 a e 24 b is a demodulator connected to transmission paths 4b and 5b from the slave station side, 15
a, 25a are modulators connected to the transmission line 4a*5a to the slave station side, 15b, 25b are the transmission lines 3b, 4 to the master station side.
modulators 16a and 26a connected to the jaw adjuster 14a;
, 24a and the modulator 15a, a regenerative repeater circuit inserted as necessary between the demodulator 14a, 16b and 26b.
b, a regenerative repeater circuit inserted between 24b and the modulators 15b, 25b as necessary; 11°27 is the modulator 15b;
, 25b are connected to the code transmitting/receiving circuit 13゜23 and demodulators 14b, 24b (or regenerative repeating circuits 16b, 26).
This is a switching circuit that connects to b') and #).

Next, the operation will be explained.

The central processing circuit 10.20 of each slave station 1, 2 constantly checks the status of monitored equipment (not shown), which is input to the digital input circuit 12.22, such as the open/closed status of a breaker, and detects any changes in status. If so, it is stored in the memory within its own circuit. Further, the central processing circuit 01 of the master station 0 instructs the number transmitting/receiving circuit 06 to transmit a code for polling each of the slave stations 1 and 2 in sequence.

The case where polling of slave station 1 is performed will now be explained. When the central processing circuit 01 instructs the code transmitting/receiving circuit 06 to transmit a code for polling the slave station 1,
The code transmitting/receiving circuit 06 creates the corresponding code and passes it to the modulator 07. Modulator 07 matches the sign of the DC pulse to the transmission path, such as frequency shift keying (FSX) and CMI (F-)' mark inversion in optical pulse transmission), and also controls noise and noise. The signal is modulated into a strong signal and sent to the transmission path 3a.

In the slave station 1, the demodulator 14a demodulates the incoming signal into a DC pulse code and passes it to the code transmitting/receiving circuit 13. At the same time, the modulator 15a performs the same modulation as described above to transmit the signal to the transmission path 4a.
Send K. Here, the regenerative repeater circuit 16a is provided as necessary to reshape and transmit when the pulse waveform is distorted during long-distance transmission.

In the slave station 2, the demodulator 24a demodulates the incoming code and passes it to the code transmitting/receiving circuit 23. Therefore, the code transmitting/receiving circuit 13 of the slave station 1 and the code transmitting/receiving circuit 23 of the slave station 2 receive the code transmitted by the code transmitting/receiving circuit 06 of the master station 0 almost simultaneously, with only a slight difference in transmission delay time. do.

The central processing circuit 10.20 of each slave station 1, 2 decodes the code received by the respective code transmitting/receiving circuit 13.23. Since the received code is a polling code for slave station 1,
The central processing circuit 10 of the slave station 1 switches the switching circuit 17 to the code transmitting/receiving circuit 13 side, and also informs the code transmitting/receiving circuit 13 whether or not the status of its own station has rarely changed, and if there has been a change, An instruction is given to transmit a code indicating specific details of the change, such as which interrupter has automatically cut off. The code transmitting/receiving circuit 13 creates a code based on instructions from the central processing circuit 10, and sends it to the transmission path 3b via the modulator 15b.

In the master station 0, the demodulator 08 receives and demodulates the signal, and passes it to the code transmitting/receiving circuit 06. The central processing bag ff01 checks whether there is a change in the status of the received code or the slave station 1, and if there is a change, changes the display on the corresponding display on the display board 04 via the digital output circuit 02.

Next, the central processing circuit 01 of the master station 0 instructs the code transmitting/receiving circuit 06 to transmit a code for polling the slave station 2 . Hereinafter, the operation until this code reaches the code transmitting/receiving circuit 13.23 of each slave station 1.2 is concave compared to the case of polling the slave station 1. This time, since the received code is a polling code for the slave station 2, the central processing circuit 20 of the slave station 2 switches the switching circuit 27 to the code transmitting/receiving circuit 23 side, and also instructs the code transmitting/receiving circuit 23 to send the code to the local station. Instructs to transmit a code indicating whether or not there has been a change in status, and if there has been a change, the specific details of the change. The code transmitting/receiving circuit 23 creates a code based on instructions from the central processing circuit 20, and sends it to the transmission path 4b via the modulator 25b.

In the slave station 1, the demodulator 16b receives and demodulates the signal, modulates it again in the modulator 15b (via the regenerative relay circuit 16b), and sends it out to the transmission line 3b.

In the master station 0, the demodulator 08 receives this and thereafter processes it in the same way as the transmission from the slave station 1, and if there is a change in status, the display on the corresponding display on the display panel 04 is changed.

The status display of the monitored equipment of each slave station 1.2 has been described above, and next, the control of each slave station 1.2 will be explained.

When performing flflJ control from master station 0 to slave station 1, when the operator operates a switch on the control console 05, the central processing unit 01 reads it via the digital input circuit 03,
The code transmitting/receiving circuit 06 is instructed to send the code for controlling the corresponding device to the corresponding slave station 1.

The code transmitting/receiving circuit 06 creates and sends the corresponding code based on instructions from the central processing bag fif01. This code is transmitted to each slave station 1, 2 by the same operation as a polling code, and the central processing unit 10.20 of each slave station 10, 2 first determines whether or not it is a control code for its own station. However, since this is for the slave station 1, the central processing circuit 10 of the slave station 1 further decodes the code and issues a control command to the corresponding device via the digital output circuit 11.

[Problem that the invention seeks to solve]

Since the conventional remote monitoring and control device is configured as described above, in order to transmit signals between the master station 0 and the slave stations 1 and 2 connected in a chain without any trouble, it is necessary to The transmission system in the downward direction from 0 to slave stations 1 and 2 and from slave stations 1 and 2 to master station 0
Therefore, the transmission lines 3a, 4a, 5a for the lower υ and the transmission lines M3b, 4b, 5b for the lower υ must be provided separately. 2%j for cables, 2% j for optical cables, etc.)
transmission path is required, and each slave station 1 and 2 has a modulator 1.
5a.

1 sb, 25a, 25b %ill adjuster 14a
, 14b, 24a, 24b-, and further regenerative relay circuit 1
6a, 16b, 26a, 26b, etc. also need to be provided separately for the upper and lower parts, which poses problems such as increased cost.

This invention was made to solve the above-mentioned problems, and requires at least one set of transmission paths for remote monitoring and control of a plurality of slave stations. The purpose of this invention is to obtain an economical remote monitoring and control device that can be used in both upstream and downstream relay circuits.

[Means for solving problems]

A device for remote monitoring control according to the present invention integrates transmission paths in the up and down directions, and a master station is provided with a modulator on the transmission path when transmitting from the master station and when transmitting from a slave station. A switching circuit is provided to disconnect the demodulator, and the slave station has 1g when transmitting from the master station and when transmitting from the slave station.
A switching circuit for reversing the connection direction of the modulator and demodulator of the transmission line -\ with time, and a switching circuit for correcting the difference in the incoming signal level of the demodulator I4 due to the reversal are provided.

Further, a remote monitoring control device according to another invention of the present invention includes:
In the above-mentioned system, an automatic gain adjustment type demodulator is used to correct the difference in the received level of the demodulator caused by the inversion.

[For production]

In the remote monitoring and control device according to the present invention, when transmitting from a master station, the master station connects a modulator to the transmission path, and each slave station connects a demodulator to the transmission path of the master station and a modulator to the transmission path on the opposite side. Connect and
In addition to receiving signals from the master station, the signals are relayed and sent to the transmission path on the opposite side from the master station. When the slave stations receive polling from the master station and transmit, the master station installs a demodulator on the transmission path. Each slave station connects a modulator to the transmission line on the master station side and a demodulator to the transmission line on the opposite side, and the slave stations between the transmitting slave station and the master station By sequentially transmitting station signals to the master station and correcting the difference in incoming signal levels at the demodulator caused by this inversion using switching circuit control, the upward and downward transmission paths are integrated, and each child The modulator and demodulator of the station can be shared between the upper and lower stations.

Further, in another aspect of the present invention, the difference in the incoming signal level of the demodulator caused by the inversion is corrected by the automatic gain control function of the demodulator.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 3, 4.5 are conventional transmission lines 3a, 3b, 4
Transmission line integrating a and 4b, 5a and 5b, 09
14.24 is a switching circuit that switches and connects the master station modulator o7 and the master station demodulator 08 to the transmission line 3; 14.24 is a conventional reconnaissance device 14;
A slave station 1 that integrates a and 14b, 24a and 24b,
2 demodulators, 15.26 are also modulators 15a and 15b.
, 25a and 25b are integrated into the modulators of the slave stations 1 and 2, 16.26 is the same regenerative relay circuit 16a and 16b,
Regenerative relay circuit integrated with 26a and 26b, 18a, 28
A is a first switching circuit that selectively connects the demodulator 14.24 to the transmission lines 3, 4 and 4.5, and 18b and 28b are connected to the modulator 15.24 in conjunction with the first switching circuit 18a*28a. 25
A second switching circuit 19.29 is connected to the demodulator 14.24 of the slave station 1.2, and the first switching circuit 18a, 28b K There is a third interlocking switching circuit, and the other parts are the same as or equivalent to those in the prior art with the same reference numerals in FIG. 2, so detailed explanation will be omitted.

Next, the operation will be explained.

The codes and procedures for transmission and reception between the master station 0 and each slave station 1 and 2 are exactly the same as in the conventional case shown in Fig. 2, and therefore the functionality is exactly the same as in Fig. 2. Since the routes through which signals flow and their circuit configurations are different, the differences will be mainly explained.

First, the polling code or control code from the master station 0 is sent from the code transmitting/receiving circuit 06 to the transmission line 3 via the modulator o7 and the switching circuit 09. In the slave station 1, the code sent from the master station 0 is passed to the code transmitting/receiving circuit 13 via the first switching circuit 18a and the demodulator 14, and
(regenerative relay circuit 16), switching circuit 17. The signal is sent to the transmission line 4 via the modulator 15 and the second switching circuit 18b. In the slave station 2, the code relayed by the slave station 1 is passed to the code transmitting/receiving circuit 23 via the first switching circuit 28a and the demodulator 24.

In each slave station 1, 2, when the code transmitting/receiving circuit 13.23 finishes receiving the polling code from the master station 0, the first switching circuit 1
8a, 28a I second switching circuit 18b, 28b.

The third switching circuits 19 and 29 are switched in the opposite direction from that shown to prepare a circuit for the polled slave station to transmit to the master station 0. At this time, in the master station 0, the switching circuit 09 is switched in the opposite direction to that shown in the figure, and the demodulator 08 is switched to the transmission path 3.
connected to.

When the slave station 1 is polled, the switching circuit 17 in the slave station 1 is switched in the opposite direction to that shown in the figure, and the code transmitted by the code transmitting/receiving circuit 13 is switched to the switching circuit 17. Modulator 15
．． The signal is sent to the transmission line 3 via the second switching circuit 18b. In master station 0, switching circuit 09. The code transmitting/receiving circuit 06 receives this via the demodulator 08.

Next, when the slave station 2 is polled, the switching circuit 27 in the slave station 2 is switched in the opposite direction to that shown in the figure, and the code transmitted by the code transmitting/receiving circuit 23 is changed to the switching circuit 27. Modulator 25. The signal is sent to the transmission line 4 via the second switching circuit 28b. In the slave station 1, the demodulator 14 receives the signal via the first switching circuit 18m and demodulates it once (regenerative relay circuit 16).
, is passed to the modulator 15 via the switching circuit 11, modulated again, and sent to the transmission line 3 via the second switching circuit 18b. In master station 0, switching circuit 09. The code transmitting/receiving circuit 06 receives this □ via the demodulator 08.

Here, the modulators 07, 15.25 normally transmit at a constant level, such as OdBm in the case of the voice band frequency deviation method, but the reception level of the demodulator 08.14.24 depends on the transmission distance and other factors. It varies from person to person depending on the conditions. Therefore, measure the level during testing before operating the equipment, and set the attenuator's tap 8 adjustment to an appropriate value. However, slave station 1
, 2, the first switching circuit 18as
By switching 28a, signals from different directions are received. For example, if the distance between master station 0 and slave station 1 and the distance between slave station 1 and slave station 2 are significantly different, the first switching circuit 18a
Due to this switching, the incoming signal level at the demodulator 14 will vary significantly, making normal reception impossible or causing problems in checking for abnormal incoming signal levels. Therefore, slave station 1.
2, the third switching circuit 19.29 is the first switching circuit 18a.
, 28a, depending on its transmission direction, the demodulator 14.
Switch the incoming call level setting of 15. The level setting can be easily changed back by changing the tap of the attenuator.

Although only two slave stations 3 are shown in FIG. 1, and the operation has been explained for slave stations 1 and 2, the third slave station
The same goes for the case where the slave stations below 6th are connected sequentially.
9. If there are only slave stations up to slave station 1 or slave station 2, there is no need to make connections beyond that, or they may be added in the future.

In the above embodiment, the switching circuit 09 of the master station, the first switching circuit 18a of the slave station, '28a e second switching circuit'
18b, 28b, third switching circuit 19, 29, etc. are conceptual diagrams of circuits that perform switching operations, and in actuality, optical switches may be used in the case of non-contact switches or optical transmission. Of course, the switching circuit 17.2T company,
Since only the slave stations that have been logically polled will transmit codes, this is omitted (that is, both the output of the regenerative repeater circuit 16.26 and the output of the code transmitter/receiver circuit 13.23 are sent to the modulator). 15.25) is also possible.

Further, the third switching circuit 19.29 controls the demodulator 14.24 with variable gain control (Automatic Ga1n Con
It is also possible to omit this by making it possible to automatically respond to changes in the incoming call level by using a ``trol'' format.

〔Effect of the invention〕

As described above, according to the present invention, the modulator, demodulator, and regenerative repeater circuit of each slave station are shared between the upstream and downstream stations, and are switched and used, and the demodulator's signal level is switched according to the connection direction. Since the configuration is such that the transmission path can be changed at least one
If you only need one set, the equipment can be configured economically, and you can afford to have the same number of transmission lines, modems, and relay circuits as before, you can use one set for regular use and one set for backup. If configured in this way, it has the effect of increasing the reliability of the entire system.

Further, in another aspect of the present invention, the above-mentioned effects are obtained by correcting the difference in incoming call level caused by the reversal of the connection direction using an automatic gain adjustment type demodulator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a remote monitoring and control device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional remote monitoring and control device. 0 is the master station, 1 and 2 are slave stations, 3.4.5 is the transmission line, 07 is the modulator of the master station, 08 is the demodulator of the master station, 09 is the switching circuit,
14.24 is a demodulator of the slave station, 15.25 is a modulator of the slave station, 18a and 28a are first switching circuits, and 18b. 28b is a second switching circuit, and 19.29 is a third switching circuit 0. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a remote monitoring and control device that connects a parent station and a plurality of slave stations in a chain via a transmission path, and transmits and receives signals between the master station and each of the slave stations by a polling method, the master station is equipped with a switching circuit that connects the modulator of the master station to the transmission path when transmitting from the master station, and the demodulator of the master station when transmitting from the slave station, and each of the slave stations connects the modulator of the master station to the transmission path when transmitting from the master station. a first switching circuit that connects the demodulator of the slave station to the transmission path in the direction opposite to the master station when transmitting to the slave station; a second switching circuit that connects the modulator of the slave station to the transmission path in the direction of the slave station, and to the transmission path in the direction of the master station when transmitting to the slave station; and an incoming signal level of the demodulator of the slave station. and a third switching circuit that switches the setting according to the connection direction,
When the master station transmits, each slave station receives a signal from the master station, relays it, transmits it to a transmission path in the opposite direction to the master station, and receives polling from the master station. A remote monitoring and control device characterized in that when the slave station transmits, the slave station located between the slave station and the master station sequentially transfers the signal of the slave station to the master station. (2) In a remote monitoring and control device that connects a parent station and a plurality of slave stations in a chain via a transmission path, and transmits and receives signals between the master station and each of the slave stations by a polling method, the master station is equipped with a switching circuit that connects the modulator of the master station to the transmission path when transmitting from the master station, and the demodulator of the master station when transmitting from the slave station, and each of the slave stations connects the modulator of the master station to the transmission path when transmitting from the master station. a first switching circuit that connects the demodulator of the slave station to the transmission path in the direction opposite to the master station when transmitting to the slave station; A second switching circuit is provided for connecting the modulator of the slave station to the transmission path in the direction of the slave station, and to the transmission path in the direction of the master station when transmitting to the slave station; The transmitter is of an automatic gain adjustment type, and when the master station is transmitting, each of the slave stations receives a signal from the master station, and relays the signal and transmits it to a transmission path in the opposite direction from the master station. , when the slave station transmits after receiving polling from the master station, the slave station located between the slave station and the master station sequentially transfers the signals of the slave station to the master station. A remote monitoring and control device.