JPH06189370A - Monitor and control system - Google Patents

Abstract

PURPOSE:To reduce the time from stop of polling due to occurrence of a fault in a master station to polling restart by a slave station by providing a timer and a polling request generation/polling reply detection means to all slave stations. CONSTITUTION:A timer 55 provided to a slave station 5 starts the operation when a polling request to the station is detected and when a polling request cannot be detected even after lapse of a prescribed time from the scheduled time of a succeeding polling request, an output of the time is sent. Then the slave station 5 sending its timer output activates a polling request generation/ polling reply detection means 52Y in the station to send a polling request to other slave station 5 in place of the master station 1. Through the constitution above, the state of disabling monitoring of all the slave stations 5 is almost eliminated and the time from the polling stop due to occurrence of a fault in the master station 1 to polling restart by the slave station 5 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring / control system for monitoring / controlling a wireless line.

For example, in a monitoring / control system in which a polling request is sequentially sent from a master station to a plurality of slave stations via a wireless line to collect information of each slave station, when a failure occurs in the master station, Even if the station is normal, the information of all the slave stations cannot be collected and the monitoring becomes impossible. Therefore, in order to prevent this, the authority to send the polling request is transferred to the specific slave station and the sending of the polling request is restarted instead of the master station, but it is necessary to shorten the time before restarting.

[0003]

2. Description of the Related Art FIG. 4 is an explanatory diagram of a conventional monitoring / control system, in which (a) is a wireless circuit configuration diagram, (b) is a frame format diagram for polling request and polling response, and (c) is for a specific slave station. It is a polling right transfer explanatory drawing. Also,
FIG. 5 is a block diagram of a main part of a conventional example of a master station and a slave station. (A) is a block diagram of a master station, (b) is a block diagram of a slave station, and (c) is a signal of the slave station. It is a principal part block diagram of a processing part.

When a failure occurs in the master station, a dotted line timer is provided in the signal processing portion of the slave station (hereinafter referred to as a specific slave station) having the right to send a polling request on behalf of the master station. ing. Hereinafter, FIG. 4 will be described with reference to FIG.

First, in FIG. 4 (a), station A and station F are B
The station A, station C, station D, and station E are connected by a wireless line, and station A as a parent station has the right to send polling requests to stations B, C, D, E, and F (see below). , And has the polling right), but it is set in advance to take over the polling right of station A when station F detects the failure of station A.

If the station A is normal, the polling request is sent out every T ₀ as shown on the left side of FIG. 4 (c)-, so that the polling request at the station F is also detected every T _0. To be done. Therefore, when station F cannot detect a polling request within (T ₀ + ΔT), station F determines that station A failure has occurred and station F sends a polling request to station B, for example (Figure 4 (c)-
(See the right side of). However, ΔT is a preset time.

Here, the polling request and the polling response are transmitted in the frame format shown in FIG. 4 (b).
In the figure, F is the flag sequence, A is the address, the slave station address of the destination when the polling request is made, and the slave station address of the source when the polling response is made. The information is a polling request or a polling response, and the FCS is an error detection signal.

Next, when the station A sends a polling request, it generates a polling request of the format shown in FIG. 4 in the transmitting side signal processing section 11 of FIG. 5 (a), and then, for example, via the transmitter 12, , Send to station B.

The receiver 24 of the station B demodulates the received signal, extracts the polling request, and sends it to the signal processing section 23 on the receiving side. When it is detected that the polling request is addressed to itself, the detection result is sent to the transmitting side. It is sent to the signal processing section 21. The transmitting-side signal processing section 21 generates a polling response in the above format using the status information of its own station collected in advance, and sends it to the A station via the transmitter 22.

The receiver 14 of station A extracts the polling response from the received signal and sends it to the signal processing section 13 on the receiving side, where the status information of station B is collected. Here, the transmitting side signal processing part and the receiving side signal processing part of station A and station B are shown in Fig. 5 (c).
The ROM 32 stores a program required for the transmission side processing or the reception side processing, and the RAM 34 stores the data required for the processing. Further, the interface 33 has a function of interfacing with a signal processing part with an external circuit. The signal processing part of the F station, which is a specific slave station, has both the functions of the A station and the slave station and the timer 35 indicated by the dotted line.

Now, the F station, which is a specific slave station, sends a polling response to the A station while the A station is operating normally, like the other slave stations. However, if the polling request addressed to the own station cannot be detected within the predetermined time, the timer output is sent from the signal processing part on the receiving side to the signal processing part on the transmitting side. So station F is A
Since the polling right has been transferred from the station, the polling request generated by the station itself is sent to the next slave station.

[0012]

As described above, according to the conventional method of delegating the polling right, if polling is stopped due to the failure of station A immediately after polling to the specific slave station F, all stations F are The polling right is transferred with the latest time up among the slave stations. Therefore, there is a problem that it takes a considerable amount of time from the occurrence of failure of station A to the sending of polling request by station F.

As a result, it becomes impossible to monitor the failure during that time, which may delay the processing for the failure. It is an object of the present invention to shorten the time from the polling stop due to the failure of the master station to the polling restart by the slave station.

[0014]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, 1 is a master station having polling request generation means and polling response detection means, 5 is a slave station, and 55 is a time when operation is started when a polling request for the self station is detected and there is a next polling request. Is a timer that outputs a timer output when a polling request cannot be detected within a predetermined time, 52Y is a polling request generation /
It is a polling response detecting means.

Then, the slave station which has sent the timer output operates the polling request / polling response detecting means in its own station to send the polling request to another slave station on behalf of the master station.

[0016]

According to the present invention, all slave stations start operating when a polling request for the local station is detected, and the polling request is issued even if a predetermined time ΔT has elapsed from the time T ₀ predicted to be the next polling request. A timer for sending a timer output when it cannot be detected and a polling request generation / polling response detection means are provided.

When station A stops sending the polling request, the station that first sends the timer output after the polling request is stopped generates the polling request and sends the polling request to the next slave station. . As a result, it is possible to almost eliminate the situation in which all slave stations cannot be monitored, and it is possible to reduce the time from the polling stop due to the failure of the master station to the polling restart by the slave stations.

[0018]

FIG. 2 is an explanatory view of a monitoring / control system to which the present invention is applied. (A) is a wireless line configuration diagram, (b) is a polling operation explanatory diagram, and (c) is a polling right delegation explanatory diagram. Further, FIG. 3 is a main part configuration diagram of an embodiment of the present invention, (a) is a main part configuration diagram of each slave station, and (b) is a main part configuration diagram of a signal processing part in (a).

Here, the configuration diagram of the main part of the master station, station A, is omitted because it is the same as FIG. 5 (a). The operation of FIG. 2 will be described below with reference to FIG. 3, but the parts described in detail above will be briefly described, and the part of the present invention will be described in detail. Since FIG. 3 is a drawing common to each slave station, B
42B when showing station transmitter, 42C when showing station transmitter
To distinguish by adding the station name after the symbol.

First, when the master station A sends a polling request, it generates a polling request in the transmitting side signal processing section 11 shown in FIG. 5 (a), and then sends it to station B via the transmitter 12. Send out.

In the station B, the receiver 44B shown in FIG. 3 (a) extracts the polling response from the received signal and sends it to the receiving side signal processing portion 43B. The signal processing part 43B on the receiving side is shown in FIG. 3 (b).
I am using the program 52XB in the ROM of the above, but if it detects that it is a polling request addressed to my station, it will use the timer 55
B is reset to operate from the initial state, and at the same time, the detection result addressed to itself is sent to the transmission side signal processing section 41B. Therefore, the status information is sent to the A station via the transmitting side signal processing section 41B and the transmitting section 42B (see the B station in FIG. 2B).

Station A repeatedly collects the status information of station B via the receiver 14 and the receiving side signal processor 13 shown in FIG. 5 (a), and repeatedly sends the polling request signal to station C (
See station B to station F in Figure 2 (b)).

As shown in FIG. 2 (c), if station A fails and a polling request cannot be sent to station D, timer 55D of station D shown in FIG. Send output to CPU 51D. Therefore, the CPU 51D determines that the polling right has been transferred, accesses the program in the area of the address Y in the ROM 52D, and sends a polling request signal to the E station via the signal processing section 41D on the transmission side and the transmission section 42D. Send out. As a result, there is almost no possibility that all stations will be unable to be monitored.

In the above, the polling right was transferred due to the failure of station A, but when station A wants to transfer the polling right for some reason, the master station requests polling without controlling the slave station. It suffices to stop the signal transmission.

According to the present invention, the detection of the polling stop due to the occurrence of the failure of the master station is accelerated, and therefore the polling restart is accelerated. As a result, there is almost no possibility that all stations will be unable to be monitored, and highly reliable polling can be realized.

[0026]

As described above in detail, according to the present invention, there is an effect that the time from the polling stop due to the failure of the master station to the polling restart by the slave station can be shortened.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

2A and 2B are explanatory diagrams of a monitoring / control system to which the present invention is applied, in which FIG. 2A is a wireless line configuration diagram, FIG. 2B is a polling operation explanatory diagram, and FIG.

3A and 3B are main-part configuration diagrams of an embodiment of the present invention, in which FIG. 3A is a main-part configuration diagram of each station, and FIG. 3B is a main-part configuration diagram of a signal processing part in FIG.

FIG. 4 is an explanatory view of a conventional monitoring / control system, (a) is a wireless circuit configuration diagram, (b) is a frame format diagram for polling request and polling response, and (c) is a delegation of polling rights to a specific slave station. It is a figure.

[Fig. 5] Fig. 5 is a main part configuration diagram of a master station and a slave station in a conventional example, (a) is a main part configuration diagram of the master station, (b) is a main part configuration diagram of the slave station, and (c) is a specific slave station. 3 is a configuration diagram of a main part of a signal processing part of FIG.

[Explanation of symbols]

 1 Master station 5 Slave station 52Y Polling request generation / polling response detection means 55 Timer

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Claims (1)

[Claims] 1. A master station (1) having a polling request generating means and a polling response detecting means, sequentially to a plurality of slave stations,
In a monitoring / control system that sends polling requests and collects information on each slave station, all slave stations (5) start operating when a polling request for their own station is detected, and there is a next polling request. A timer (55) that outputs a timer output when a polling request cannot be detected within a predetermined time from the predicted time
And the polling request generation / polling response detection means (55
Y) is provided, and the slave station transmitting the timer output operates the polling request / polling response detecting means in its own station to transmit the polling request to another slave station on behalf of the master station. A monitoring and control system characterized by that.